CN201462582U

CN201462582U - Sidelight type backlight module of CCFL

Info

Publication number: CN201462582U
Application number: CN2009201104820U
Authority: CN
Inventors: 郑效盼; 金�雄; 尚飞; 刘海军; 孙海威
Original assignee: Beijing BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Beijing BOE Optoelectronics Technology Co Ltd
Priority date: 2009-08-04
Filing date: 2009-08-04
Publication date: 2010-05-12
Anticipated expiration: 2019-08-04

Abstract

The utility model provides a sidelight type backlight module of a CCFL (Cold Cathode Fluorescent Lamp), which comprises a light guide plate and a CCFL arranged on the side surface of the light guide plate. The sidelight type backlight module is characterized in that along the lengthwise direction of the CCFL, the thickness from the upper surface of the light guide plate to the lower surface of the light guide plate increases from the center to two ends. The sidelight type backlight module provided by the utility model can effectively improve the brightness on the left side and the right side of the backlight module and improve the homogeneity of the backlight module through adopting the light guide plate higher at two ends and lower in the center, thereby solving the problem of brightness homogeneity relating to angel in TCO and improving the utilization rate of a light source.

Description

CCFL side-light type back light module

Technical field

The utility model relates to backlight of LCD and makes the field, relates in particular to a kind of CCFL side-light type back light module.

Background technology

Backlight module is LCD (Liquid Crystal Display; Hereinafter to be referred as: LCD) providing light source, is the important composition parts of LCD.In the prior art in view of cathode fluorescent tube (hereinafter to be referred as: CCFL) have technical maturity, steady performance, generally all select for use CCFL as the electroluminescent lamp group in the backlight module.In order to reduce the thickness of LCD, the side of CCFL operated by rotary motion LGP in backlight is used as doing the sidelight source.

Fig. 1 is existing CCFL side-light type back light modular structure schematic diagram, as shown in Figure 1, this backlight module comprises the LGP 2 that is arranged on the backboard 1, the top of LGP 2 is provided with the optics module 3 that comprises diffusion sheet, prismatic lens and following diffusion sheet, be provided with CCFL4 in the side of LGP 2 and provide light for backlight, in order to improve the luminous efficiency of CCFL4, around CCFL4, be provided with reflector 5, the cross section of reflector 5 is " U " type structure, and the light that CCFL4 is emitted all is transmitted into LGP 2 inside.

In the existing C CFL side-light type back light structure, LGP is identical along thickness on the length direction of CCFL.Because the luminous efficiency at CCFL center and two ends is different, therefore LGP adopts the set-up mode of same thickness, do not consider the problem of effective light-emitting zone of CCFL, cause the centre of LGP exiting surface different, cause backlight source module all once bad with two ends brightness.In addition, owing to have certain space between the upper surface of reflector and LGP, therefore be easy to generate the white line phenomenon in the prior art.

The utility model content

In order to solve all once bad defective of backlight module in the prior art, the utility model provides a kind of CCFL side-light type back light module, thereby solves the TCO problem.

The utility model provides a kind of CCFL side-light type back light module, comprise LGP, and the CCFL that described LGP side is set, along on the length direction of described CCFL, the upper surface of described LGP is increased progressively by middle mind-set two ends to the thickness of the lower surface of described LGP.

The CCFL side-light type back light module that the utility model provides, by LGP being arranged to the low shape in high center, two ends, can improve the brightness of the backlight module left and right sides effectively, improve the homogeneity of backlight module, thereby can solve the problem and the utilization rate that improves light source of the brightness homogeneity of angle association among the TCO.

Description of drawings

Fig. 1 is existing CCFL side-light type back light modular structure schematic diagram;

Fig. 2 is brightness and the length relation curve synoptic diagram of CCFL;

Fig. 3 is the thickness of LGP and the optical efficiency relation curve schematic diagram of light inlet;

Fig. 4 is the thickness change curve schematic diagram in the longitudinal direction of LGP;

Fig. 5 is the utility model CCFL side-light type back light module example structure schematic diagram;

Fig. 6 is a reflector structural upright schematic diagram in the utility model CCFL side-light type back light module;

Fig. 7 is a reflector structure side view in the utility model CCFL side-light type back light module.

The specific embodiment

Further specify the technical scheme of the utility model embodiment below in conjunction with the drawings and specific embodiments.

In the side-light type back light module of CCFL as the lamp assembly, be specially a little less than the brightness at CCFL two ends because the luminous efficiency at CCFL two ends and center is different, the brightness at center is stronger, prior art is not considered the problem of the effective light-emitting zone of above-mentioned CCFL, in backlight module, adopt the LGP of equal thickness, like this because CCFL brightness irregularities in the longitudinal direction, upwards the intensity of the light of emission is also inhomogeneous to cause LGP, be specially LGP two ends emissions light a little less than, center emission light is stronger, has therefore caused all once bad defective of backlight module.There is effective light-emitting zone at CCFL, and LGP is with the also different characteristics of different its leaded light efficient of thickness, the utility model provides a kind of novel CCFL side-light type back light module, in this side-light type back light module, be that backlight module provides light source as the lamp assembly still with CCFL, CCFL is arranged on the side of LGP, for the intensity homogenising that makes that light is upwards launched in corresponding CCFL two ends of LGP and corresponding CCFL center, and in conjunction with CCFL two ends emissions light a little less than, the stronger characteristic of center emission light, make the thickness of LGP clocklike change LGP as particular processing, be specially along on the length direction of described CCFL, the upper surface of LGP increases progressively the above-mentioned LGP that provides to the thickness of the lower surface of LGP by middle mind-set two ends and is applied in the common side-light type CCFL backlight, can improve the brightness of the backlight module left and right sides effectively, improve the homogeneity of backlight module; Thereby can solve the problem and the utilization rate that improves light source of the brightness homogeneity of angle association among the TCO.

Below introduce design principle of the present utility model.The thickness of LGP is to change on the CCFL length direction along the long axis direction of LGP, and Fig. 2 is brightness and the length relation curve synoptic diagram of CCFL, and as shown in Figure 2, the brightness of CCFL center is approximately 68000cd/m ², the brightness at end points place is approximately 60000cd/m ², the CCFL center brightness is bigger than two ends brightness as can be known.Fig. 3 is the thickness of LGP and the optical efficiency relation curve schematic diagram of light inlet, and as shown in Figure 3, when light guide plate was 6mm, optical efficiency was approximately 65%, and light guide plate is when being 6.2mm, and optical efficiency is approximately 74%.Hence one can see that, when light guide plate is big, and the optical efficiency height.In summary, for improve backlight module all once, can change the thickness of LGP, thereby it is identical to make CCFL two ends and mid portion inject the luminous flux of LGP.Fig. 4 is the thickness change curve schematic diagram in the longitudinal direction of LGP, and the varied in thickness of LGP can be referring to preparation shown in Figure 4 in the utility model.

Fig. 5 is the utility model CCFL side-light type back light module example structure schematic diagram, as shown in Figure 5, comprise the LGP 2 on the backboard in this CCFL side-light type back light module, and LGP 2 tops comprise diffusion sheet, the optics module (not shown) of prismatic lens and following diffusion sheet, side at LGP 2 is provided with CCFL4, for improve backlight module all once, and a little less than the brightness in conjunction with the CCFL two ends, the characteristic that the brightness at center is stronger, the incidence surface of LGP 2 is arranged to special shape, the incidence surface of described LGP 2 is the side surface 23 of LGP 2 towards CCFL4, and the light that CCFL4 emits enters LGP 2 by this incidence surface.It is not a rectangle to the special shape of LGP 2 as shown in the figure, and is the shape that the two ends area is big, the center area is little.Particularly, along on the direction of CCFL4 length L, the upper surface 21 of LGP 2 increases progressively to the thickness of the lower surface 22 middle mind-set two ends by LGP 2, in Fig. 2, the upper surface 21 of LGP 2 is H to the distance of lower surface 22 on the position at the two ends of LGP 2, the upper surface 21 of LGP 2 is h to the distance of lower surface 22 on the position at the center of LGP 2, and H＞h.The upper surface 21 that should be noted that LGP 2 can be a deformationization linearly, also can be curved variation, and the amplitude of the thickness-tapered of LGP 2 can be with reference to the luminosity change curve of CCFL fluorescent tube.

The LGP that present embodiment provides with special shape, the characteristics that corresponding CCFL two ends brightness is weak, center brightness is strong, along the CCFL length direction, the two-end thickness of LGP is big, center thickness is little, the LGP two ends are because of the weak relatively light of the big and many receiving intensity of incidence surface like this, the LGP center position lacks the strong relatively light of receiving intensity because of incidence surface is little, the brightness in the two ends of LGP exiting surface and centre is close like this, the influence that variation by light guide plate comes the effective light-emitting zone of balance CCFL to be brought, provide backlight module all once.

Fig. 6 is a reflector structural upright schematic diagram in the utility model CCFL side-light type back light module, and Fig. 7 is a reflector structure side view in the utility model CCFL side-light type back light module.Further, the light that emits for good utilisation CCFL more, present embodiment also is provided with a reflector around CCFL, shown in Fig. 5,6 and 7, the cross section of reflector 5 is " U " type structure, and the last reflecting plate 51 of reflector 5 closes on the marginal position of LGP 2, is provided with to following reflecting plate 52 directions of reflector 5 to be used to stop that light passes through the shutter 53 that the gap between last reflecting plate 51 and the LGP 2 is penetrated.The shutter 53 of the setting on the reflector 5 can prevent that light that CFFL4 emits is by the gap 54 between last reflecting plate 51 and the LGP.

In order to mate the characteristics that the LGP two-end thickness is big, center thickness is little, shutter 53 on the reflector 5 that provides in the utility model backlight module can be prepared into the shape that is complementary with LGP 2 shapes, promptly along on the length direction L of CCFL4, the height of shutter 53 is increased progressively to the center by two ends, shutter 53 is upside-down triangle shape as shown in Figure 2, and shutter 53 can shelter from the concave portions that the LGP upper surface occurs just.

In the reflector that has shutter that the foregoing description provides, reflector and shutter can be wholely set, and specifically can carry out different settings according to the actual requirements.

The CCFL side-light type back light module that the utility model provides, by LGP being arranged to the low shape in high center, two ends, can improve the brightness of the backlight module left and right sides effectively, improve the homogeneity of backlight module, thereby can solve the problem and the utilization rate that improves light source of the brightness homogeneity of angle association among the TCO; And the shutter on the reflector can also prevent light leak effectively, avoids occurring between LGP and the reflector white line phenomenon.

It should be noted that at last: above embodiment only in order to the explanation the technical solution of the utility model, is not intended to limit; Although the utility model is had been described in detail with reference to previous embodiment, those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the spirit and scope of each embodiment technical scheme of the utility model.

Claims

1. CCFL side-light type back light module, comprise LGP, and the CCFL that described LGP side is set, it is characterized in that, along on the length direction of described CCFL, the upper surface of described LGP is increased progressively by middle mind-set two ends to the thickness of the lower surface of described LGP.

2. CCFL side-light type back light module according to claim 1, it is characterized in that, also comprise be around in around the described CCFL, cross section is the reflector of " U " type structure, and the last reflecting plate of described reflector closes on the marginal position of described LGP, is provided with to the following reflecting plate direction of described reflector to be used to stop that light passes through the described shutter of going up the gap ejaculation between reflecting plate and the described LGP.

3. CCFL side-light type back light module according to claim 2 is characterized in that along on the length direction of described CCFL, the height of described shutter is increased progressively to the center by two ends.

4. according to claim 2 or 3 described CCFL side-light type back light modules, it is characterized in that described reflector and described shutter are structure as a whole.