CN102466170A

CN102466170A - Backlight module

Info

Publication number: CN102466170A
Application number: CN2010105407514A
Authority: CN
Inventors: 张玉芬; 简克伟
Original assignee: Rongchuang Energy Technology Co ltd; Zhanjing Technology Shenzhen Co Ltd
Current assignee: Rongchuang Energy Technology Co ltd; Zhanjing Technology Shenzhen Co Ltd
Priority date: 2010-11-11
Filing date: 2010-11-11
Publication date: 2012-05-23

Abstract

The invention provides a backlight module. The backlight module comprises a light emitting diode, a diffuser plate, a prism sheet and a polarizer, wherein light emitted by the light emitting diode exits through the diffuser plate, the prism sheet and the polarizer; fluorescent powder is arranged on the surface of the prism sheet in an optical propagation path of the light emitting diode. According to the backlight module, a uniform light mixing effect can be acquired.

Description

Module backlight

Technical field

The present invention relates to a kind of module backlight, be meant a kind of LED backlight module especially.

Background technology

But display screen plays in daily life widely and uses as the electronic installation of a kind of display text and image.Present display screen can mainly be divided into two kinds according to its material: a kind of is Organic Light Emitting Diode screen (OLED; Organic light-emitting display); A kind of in addition is TFT screen (TFT, thin film transistor).Because the cost of OLED screen is higher, though therefore plurality of advantages is arranged, range of application is restricted.The TFT screen then relies on its bigger price advantage, and application at present still accounts for main flow.Yet the TFT screen itself does not have lighting function, therefore need be equipped with the corresponding backlight module to it usually and throw light on.

The light source that is adopted in the existing module backlight is generally two types of cathode fluorescent tube (CCFL, cold cathode fluorescent lamp) and light emitting diodes (LED, light emitting diode).Cathode fluorescent tube since its time of occurrence early, technological comparative maturity remains the first-selection of most of display screen module backlight at present.The technology of light emitting diode is started late, and also just on part display screen product, related application is arranged at present.Yet, owing to numerous advantages are arranged than cathode fluorescent tube, such as volume is little, in light weight, energy consumption is low, pollution-free etc., the application of following light emitting diode will be expanded gradually, it is imperative to replace cathode fluorescent tube.

Because display screen needs white light to throw light on, and for the light emitting diode of single chip, also can't directly produce white light at present, therefore normally adopt the mode of mixed light to come synthesize white light.The mixed light mode of current comparatively main flow adds yellow fluorescent powder for the blue-light-emitting chip.Yet, because the volume of light emitting diode is less, cause easily being doped in the fluorescent material skewness in its packaging body, make the white light of output the phenomenon of colour cast occur, and then influence the display effect of display screen.

Summary of the invention

Therefore, be necessary to provide a kind of module backlight of even light mixing.

A kind of module backlight comprises light emitting diode, diffuser plate, prismatic lens and Polarizer, and the light that light emitting diode sends is through diffuser plate, prismatic lens and Polarizer outgoing, and prismatic lens is provided with fluorescent material on the surface in the light emitting diode propagation path of light.

Because fluorescent material is arranged on the prismatic lens surface, its bigger area can guarantee that fluorescent material is evenly distributed, and then makes even light mixing, avoids the phenomenon of colour cast to take place.

With reference to the accompanying drawings, in conjunction with specific embodiment the present invention is done further description.

Description of drawings

Fig. 1 is the sketch map of the module backlight of first embodiment of the invention.

Fig. 2 is the sketch map of the module backlight of second embodiment of the invention.

Fig. 3 is the sketch map of the module backlight of third embodiment of the invention.

The main element symbol description

LGP	10
		Incidence surface	12
Exiting surface	14
		Light emitting diode	20
Diffuser plate	30
		Incidence surface	32
Exiting surface	34
		Prismatic lens	40
Incidence surface	42
		Exiting surface	44
Polarizer	50
		Yellow fluorescent powder	60
Red fluorescence powder	62
		Green emitting phosphor	64

The specific embodiment

See also Fig. 1, show the module backlight of first embodiment of the invention.This module backlight is used for display screen (figure does not show) is thrown light on, and to make things convenient for the user display screen institute content displayed is observed.Module backlight comprises a LGP 10, some light emitting diodes 20 that is arranged at LGP 10 opposite ends, be located at LGP 10 tops a diffuser plate 30, be arranged at a prismatic lens 40 of diffuser plate 30 tops and be arranged at a Polarizer 50 of prismatic lens 40 tops.

This LGP 10 can be by the acrylic resin, to gather the higher material of transparencies such as carbon resin made.LGP 10 is rectangular, and its two side faces that is right against light emitting diode 20 is an incidence surface 12, and its end face is an exiting surface 14.The light that light emitting diode 20 sends gets into LGP 10 inside through the incidence surface 12 of LGP 10, and part light is directly from exiting surface 14 outgoing, and part light is through the bottom surface total reflection of LGP 10 and then from exiting surface 14 outgoing in addition.For avoiding light to reveal from the bottom surface of LGP 10, the bottom surface of LGP 10 also can further form a reflecting layer (figure does not show).This reflecting layer can be made by metal material, like silver, aluminium, gold etc.In addition, also can form a plurality of diffusion points (figure does not show) on the bottom surface of LGP 10, in order to light is spread.These diffusion points can be formed through screen painting or other modes by the ink material (like titanium dioxide or silica) of high reflectance.These diffusion points can be arranged in specific pattern to reach different astigmatic effects.The effect of this LGP 10 is it upwards to be propagated the light adjustment direction of self-luminous diode 20 levels ejaculation.

These light emitting diodes 20 are divided near two incidence surfaces 12 of LGP 10.Each light emitting diode 20 is and adopts the blue-light-emitting chip blue light diode of (figure does not show) in the present embodiment.This blue-light-emitting chip can adopt semiconductive luminescent materials such as gallium nitride, InGaN, aluminum indium nitride gallium made.Light emitting diode 20 is right against the incidence surface 12 of LGP 10, so that light level is injected in the LGP 10.Can directly fit between the incidence surface 12 of light emitting diode 20 and LGP 10, also can be bonding through transparent colloid (figure does not show), to reduce light loss in the air.

Diffuser plate 30 is arranged at LGP 10 tops.This diffuser plate 30 can be made by the Merlon or the polymethyl methacrylate that are doped with the diffusion particulate.Diffuser plate 30 will spread from the light that LGP 10 exiting surfaces 14 are injected through its inner diffusion particulate, makes light equably from its exiting surface 34 directive prismatic lenses 40.

Prismatic lens 40 is arranged at diffuser plate 30 tops.Prismatic lens 40 can be made by transparent materials such as polynary ester or Merlon.Prismatic lens 40 is formed with a plurality of continuous triangle corner angle (figure is mark not) on its exiting surface 44.Preferably between 24 μ m～110 μ m, the angle of each corner angle is preferably between 90～110 degree for spacing between the adjacent ribs angular vertex.Prismatic lens 40 is used to adjust the angle of the light of being injected from diffuser plate 30, the light through diffuser plate 30 scatterings is collimated and makes it to be limited to outgoing in the specific angular field of view, thereby promote the briliancy in this angular field of view.Be coated with one deck yellow fluorescent powder 60 on each corner angle of prismatic lens 40, be used to change the color of output light.Originally be that yellow fluorescent powder 60 can be made between the fluorescent material of yellow band for transmitted spectrums such as yttrium-aluminium-garnet, silicate compound, nitride, nitrogen oxide among the embodiment.Because light can repeatedly reflect on corner angle and reflect to reach the collimation effect, being coated on yellow fluorescent powder 60 on each corner angle gold-tinted that is sent that is stimulated can mix with blue light fully, thereby obtains the higher white light of the uniformity.In addition, because the area of the exiting surface 44 of prismatic lens 40 is much larger than the area of light emitting diode 20, yellow fluorescent powder 60 can be smeared comparatively equably, thereby further guarantees the uniformity of mixed light.Certainly, the position of yellow fluorescent powder 60 is not limited on the corner angle on prismatic lens 40 exiting surfaces 44, and it can also be coated on the incidence surface 42 of prismatic lens 40, can reach the purpose of even light mixing equally.

Polarizer 50 is positioned at prismatic lens 40 tops.Polarizer 50 is made up of the multilayer materials film, and it is used for the light polarization with prismatic lens 40 outputs, and the light that makes a certain polarised direction is through filtering the light of other directions.

Be appreciated that ground, above-mentioned yellow fluorescent powder 60 can also as shown in Figure 2ly be coated on the incidence surface 32 of diffuser plate 30.Through repeatedly refraction and the reflection of light in diffuser plate 30, can reach the purpose of even mixed light equally.In addition, add the blue synthetic not enough problem of white light color rendering, can also apply one deck red fluorescence powder 62 (being to be coated on the exiting surface 44 of prismatic lens 40 among Fig. 2) on the exiting surface 44 of prismatic lens 40 or the incidence surface 42 for remedying yellow.It is made that this red fluorescence powder 62 can be positioned at the fluorescent material of red spectral band by transmitted spectrums such as alkaline earth sulfide, zinc sulphide type sulfide, silicate compound, aluminate compound, nitrogen oxide.Through adding red fluorescence powder 62, the color rendering of final white light can rise to about in the of 80 by original about 70.

It is also understood that ground, for further promoting the color rendering of output white light, the mode synthesize white light that also can adopt the RGB three primary colors to mix.Such as, can be on any two faces in the exiting surface 14 of the exiting surface 44 of the exiting surface 34 of diffuser plate 30 and incidence surface 32, prismatic lens 40 and incidence surface 42 and LGP 10 coated red fluorescent material 62 and green emitting phosphor 64 respectively.A kind of in the above-mentioned various combination has been shown among Fig. 3, and promptly red fluorescence powder 62 is positioned on the exiting surface 44 of prismatic lens 40, and green emitting phosphor 64 is positioned on the exiting surface 14 of LGP 10.It is made that this green emitting phosphor 64 can be positioned at the fluorescent material of green light band by transmitted spectrums such as yttrium-aluminium-garnet, aluminate compound, nitride, nitrogen oxide.Through the mixing of three kinds of light of RGB, can make the color rendering of output white light be promoted to 90～100, thereby adapt to the lighting demand of some particular screen curtain.

In addition, above-mentioned various

fluorescent material

60,62,64 can also just be entrained in its inside in advance in above-mentioned each element manufacture process, and are not limited to be coated on the surface of each element.

In addition, light emitting diode 20 all is to be provided with the luminous mode of side among above-mentioned each embodiment, therefore needs LGP 10 to change the radiation direction of light emitting diode 20, makes its outgoing towards the top.Be appreciated that ground, light emitting diode 20 can also adopt the mode of straight-down negative to be provided with, even the light direction of light emitting diode 20 directly up, thereby saves LGP 10, further saves cost.

Claims

1. module backlight; Comprise light emitting diode, diffuser plate, prismatic lens and Polarizer; The light that light emitting diode sends is through diffuser plate, prismatic lens and Polarizer outgoing, and it is characterized in that: the surface that prismatic lens is positioned at the propagation path of light of light emitting diode is provided with fluorescent material.

2. module backlight as claimed in claim 1 is characterized in that: the exiting surface of prismatic lens is provided with fluorescent material.

3. module backlight as claimed in claim 2 is characterized in that: have a plurality of corner angle on the exiting surface of prismatic lens, fluorescent material is arranged on the corner angle.

4. module backlight as claimed in claim 2 is characterized in that: the transmitted spectrum of the fluorescent material that is provided with on the prismatic lens exiting surface is between yellow band.

5. module backlight as claimed in claim 1 is characterized in that: also be provided with fluorescent material on the incidence surface of diffuser plate.

6. module backlight as claimed in claim 5 is characterized in that: the transmitted spectrum of the fluorescent material on the diffuser plate incidence surface is between yellow band.

7. module backlight as claimed in claim 6 is characterized in that: the transmitted spectrum of the fluorescent material that is provided with on the prismatic lens surface is between red spectral band.

8. module backlight as claimed in claim 1 is characterized in that: also comprise LGP, light emitting diode is provided with near the side of LGP.

9. module backlight as claimed in claim 8 is characterized in that: the exiting surface of LGP is provided with green emitting phosphor, and the fluorescent material that is provided with on the prismatic lens surface is red fluorescence powder.

10. like each described module backlight of claim 1 to 9, it is characterized in that: light emitting diode is a blue light diode.