CN103851410A

CN103851410A - Backlight module

Info

Publication number: CN103851410A
Application number: CN201210502178.7A
Authority: CN
Inventors: 陈柏洲
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2012-11-30
Filing date: 2012-11-30
Publication date: 2014-06-11

Abstract

A backlight module comprises a light-emitting diode, a lens and a diffusion plate. The light-emitting diode comprises a light-emitting chip, scattering particles and fluorescent powder particles are evenly distributed in the diffusion plate, light emitted by the light-emitting diode enters the diffusion plate through the lens and is scattered through the scattering particles to excite the fluorescent powder particles to emit light, and mixed light is formed and discharged out of a light guide plate. The backlight module can effectively prevent color shift, and a screen can have the uniform lighting effect.

Description

Backlight module

Technical field

The present invention relates to a kind of backlight module, refer to especially a kind of down straight aphototropism mode set.

Background technology

Light emitting diode, as emerging light source, has been widely used in the middle of various uses.The comparatively general field of current light emitting diode application surely belongs to display backlight module.Because the cause that light emitting diode size is little, use light emitting diode can manufactured place comparatively frivolous as the display of backlight module, thereby the portability of display or sight are greatly promoted.

The mode that existing down straight aphototropism mode set normally adopts light emitting diode, lens and diffuser plate to coordinate is thrown light on to screen.The white light that light emitting diode sends enters in diffuser plate after the diffusion of lens, then passes through the further scattering of diffuser plate, forms uniform bright dipping to screen illumination.

But in this kind of backlight module, light emitting diode is by being coated in yellow fluorescent powder on blue-light-emitting chip and producing white light.Because luminescence chip area is less, yellow fluorescent powder is also not easy to be coated in equably on luminescence chip.Once apply unevenly, will easily cause the problem of blue light and yellow light mix inequality, make white light that light emitting diode sends occur the phenomenon of colour cast.Even through the scattering of diffuser plate, be also difficult to the situation of the colour cast of eliminating white light, cause the light that finally exposes to screen to occur aberration, have influence on the display effect of screen.

In addition, the refractive index difference of the lens that light emitting diode is equipped with to blue light and gold-tinted, thereby the white light that sends of light emitting diode is through after lens, blue light will, with outside different angles of emergence ejaculation lens, further aggravate the phenomenon of colour cast with gold-tinted.

Summary of the invention

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

A kind of backlight module, comprise light emitting diode, lens and diffuser plate, light emitting diode comprises luminescence chip, diffuser plate inside is evenly distributed with microscopic scatterers and fluorescent powder grain, after the light that luminescence chip sends enters diffuser plate via lens, the fluorescence excitation powder particles via the scattering of microscopic scatterers, and then be mixed into uniform white light ejaculation diffuser plate.

Because the size of diffuser plate is conventionally larger, therefore fluorescent material is easier to be distributed in equably in diffuser plate, can avoid the colour cast phenomenon causing due to fluorescent material skewness.And light is excite in diffuser plate and mix, therefore can further reduce because lens are for the different colour casts that cause of refractive index of different colours light.

With reference to the accompanying drawings, the invention will be further described in conjunction with specific embodiments.

Brief description of the drawings

Fig. 1 shows the schematic diagram of the backlight module of one embodiment of the invention.

Main element symbol description

Screen	10
		Substrate	20
Light emitting diode	30
		Luminescence chip	32
Packaging body	34
		Pedestal	36
Lens	40
		Incidence surface	42
Exiting surface	44
		Supporting surface	46
Cavity	48
		Diffuser plate	50
Microscopic scatterers	52
		Fluorescent powder grain	54

Following detailed description of the invention further illustrates the present invention in connection with above-mentioned accompanying drawing.

Detailed description of the invention

Refer to Fig. 1, show the backlight module of first embodiment of the invention, it is for throwing light on to a screen 10.This backlight module comprises a substrate 20, a light emitting diode 30, lens 40 and a diffuser plate 50.

In the present embodiment, substrate 20 is a circuit board, thinks that light emitting diode provided thereon 30 provides electric energy.Preferably, this substrate 20 is an aluminium base or copper base circuit board, light emitting diode 30 is dispelled the heat in power supply.

Light emitting diode 30 is fixed on substrate 20 end faces.Light emitting diode 30 comprises that a pedestal 36, a luminescence chip 32 and that is fixed on pedestal 36 end faces cover the packaging body 34 of luminescence chip 32.This pedestal 36 preferably adopts the heat-conducting insulation materials such as pottery to make, and so that luminescence chip 32 is worked, the heat producing is passed on substrate 20.In the present embodiment, this luminescence chip 32 is blue chip, and it can be made up of semiconductive luminescent materials such as gallium nitride, InGaN, aluminum indium nitride galliums.Certainly, other semiconductive luminescent materials also can be used for manufacturing the luminescence chip 32 of the present embodiment, to produce different glow colors.This packaging body 34 is made up of transparent material, as epoxy resin, silica gel, glass etc.Packaging body 34 is fixed on pedestal 36 end faces with by isolated to luminescence chip 32 and external environment, prevents that luminescence chip 32 is subject to the impact of extraneous moisture or dust.This packaging body 34 is an individual dome-like structures, its as Primary lens so that the light of luminescence chip 32 is tentatively regulated.

These lens 40 cover light emitting diode 30.These lens 40 are also made up of transparent material, as Merlon or polymethyl methacrylate.Lens 40 comprise that an incidence surface 42, an exiting surface 44 and relative with incidence surface 42 connect the supporting surface 46 of incidence surface 42 and exiting surface 44.In the present embodiment, this incidence surface 42 is a concave surface, and exiting surface 44 is a convex surface, and supporting surface 46 is a plane.This supporting surface 46 is placed in the end face of substrate 20 so that lens 40 are supported on substrate 20.This incidence surface 42 encloses and forms a cavity 48, to accommodate light emitting diode 30.The curvature of this incidence surface 42 is preferably greater than the curvature of exiting surface 44, thereby makes lens 40 have the effect of scattered beam.The light that these lens 40 send light emitting diode 30 as Secondary lens spreads, and blue light is incident on diffuser plate 50 with the larger angle of emergence.

Diffuser plate 50 is made up of the material of printing opacity, as polymethyl methacrylate or polystyrene resin.The interior Uniform Doped of diffuser plate 50 has microscopic scatterers 52 and fluorescent powder grain 54.Microscopic scatterers 52 can be made up of the material such as such as silica gel, polymethyl methacrylate, polystyrene resin, and its particle diameter is preferably between 0.5 ~ 20 μ m.Fluorescent powder grain 54 adopts the fluorescent material that goes out gold-tinted such as yttrium-aluminium-garnet, silicate equal excitation to make, and its particle diameter is preferably between 1 ~ 30 μ m.Certainly, fluorescent powder grain 54 can also adopt red fluorescence material and green fluorescent material to mix and manufacture, to obtain better color rendering.In the present embodiment, the particle diameter of fluorescent powder grain 54 is greater than the particle diameter of microscopic scatterers 52.Microscopic scatterers 52 and fluorescent powder grain 54 can just mix still in liquid diffuser plate 50 materials before diffuser plate 50 moulding, and then by stirring or after other modes mix, together injecting moulding with liquid diffuser plate 50 materials.

The blue light that light emitting diode 30 sends, via after lens 40 diffusions, is injected in diffuser plate 50 with the larger angle of emergence.In the communication process of blue light in diffuser plate 50, via the refraction of microscopic scatterers 52 and reflection to all directions random scatter.The blue light of scattering and then fluorescence excitation powder particles 54, make its transmitting gold-tinted.The gold-tinted exciting further acts on microscopic scatterers 52 again, is scattered into all directions and launches at random once again.Finally, after fully mixing with gold-tinted through the blue light of Multiple Scattering, penetrate and expose to screen 10 from diffuser plate 50, thereby make screen 10 obtain uniform white light.

Because diffuser plate 50 sizes are larger, therefore fluorescent powder grain 54 is easy to be evenly distributed in diffuser plate 50 in the middle of manufacture process, on processing procedure, easily controls.And, because blue light becomes gold-tinted to mix in diffuser plate 50 internal conversions again, therefore can reduce because lens 40 are for the different colour cast phenomenons that cause of refractive index of the light of different spectral.Therefore, backlight module of the present invention can be realized illuminating effect comparatively uniformly.

Claims

1. a backlight module, comprise light emitting diode, lens and diffuser plate, light emitting diode comprises luminescence chip, it is characterized in that: in diffuser plate, be evenly distributed with microscopic scatterers and fluorescent powder grain, the light that light emitting diode sends is after lens are incident to diffuser plate, the excitated fluorescent powder particle light-emitting via the scattering of microscopic scatterers, and then formation mixed light penetrates from LGP.

2. backlight module as claimed in claim 1, is characterized in that: the light that light emitting diode sends is blue light, and the fluorescent powder grain light sending that is stimulated is gold-tinted.

3. backlight module as claimed in claim 1, is characterized in that: the particle diameter of microscopic scatterers is less than the particle diameter of fluorescent powder grain.

4. backlight module as claimed in claim 1, is characterized in that: lens comprise incidence surface and the exiting surface relative with incidence surface, and the incidence surface of lens surrounds the cavity of accommodating light emitting diode.

5. backlight module as claimed in claim 4, is characterized in that: the incidence surface of lens is concave surface, and exiting surface is convex surface.

6. backlight module as claimed in claim 5, is characterized in that: the curvature of the incidence surface of lens is greater than the curvature of exiting surface.

7. backlight module as claimed in claim 4, is characterized in that: also comprise the substrate that supports light emitting diode, lens are fixed on substrate.

8. backlight module as claimed in claim 7, is characterized in that: substrate is a metal-based circuit board.

9. backlight module as claimed in claim 7, is characterized in that: lens also comprise the supporting surface that connects incidence surface and exiting surface, and the supporting surface of lens is placed on substrate.

10. backlight module as claimed in claim 1, is characterized in that: light emitting diode also comprises the packaging body that covers luminescence chip, doping fluorescent powder not in packaging body.