CN1800941A - Backlight module assembly - Google Patents

Abstract

The invention discloses a negative phototropic mould, which consists of light conducting plate and at least one point light source, wherein the light conducting plate contains a light inlet face, a light outlet face and a soffit corresponding to the light outlet face; the point light source is set near the light conducting plate, whose surface is covered by packing resin to protect the point light source; the resin is filled between the point light source and light inlet face, which makes the refractive index of resin more than the air dielectrics' to reduce the light energy loss and improve the brightness of negative phototropic mould.

Description

Module backlight

[technical field]

The invention relates to a kind of backlight liquid crystal display module that is used for.

[background technology]

Because advantages such as LCD has gently, approaches, power consumption is little are widely used in modernized information equipments such as notebook, mobile phone, personal digital assistant.Because liquid crystal itself does not have the characteristics of luminescence, being required to be it provides module backlight to realize Presentation Function.

Existing module backlight comprises light source and light guide plate, and light source is the incidence surface setting of relative light guide plate, and the transmission direction that this light-guide plate guides is sent light beam from light source converts line source or pointolite to the area source ejaculation.A plurality of sites that distribute, the bottom surface of this light guide plate in order to the total reflection condition of broken beam in the light guide plate internal transmission, and make its scattering improving the homogeneity of light guide plate outgoing beam, thereby promote the overall performance of module backlight.The density of this site, size all can have different designs to adapt to different modules backlight.The pointolite that module backlight mainly uses is LED (Light EmittingDiodes, a light emitting diode) light source.

Seeing also Fig. 1 and Fig. 2, is the module a kind of backlight that the TaiWan, China patent of on October 1st, 2004 bulletin discloses for the 245th, No. 426.This module 1 backlight comprises a light guide plate 11 and a plurality of pointolite 12, i.e. LED.This light guide plate 11 is plate shaped light guide plate, is to adopt transparent materials such as acryl, glass or polycarbonate to make, and it comprises exiting surface 112 and and exiting surface 112 opposed bottom surface 113 that an incidence surface 111 links to each other with incidence surface 111.This pointolite 12 is in a side of the incidence surface 111 of this light guide plate 11, and it is not damaged for protecting this pointolite 12 in order to emit beam, and its surface is surrounded by potting resin 121.The transmission direction that these light guide plate 11 these pointolites 12 of guiding send light beam is converted into area source and penetrates.

Because the surface of this pointolite 12 is surrounded by potting resin 121, so the light that this pointolite 12 sends has two secondary reflections before entering light guide plate 11, first reflection produces in the junction of this potting resin 121 and air dielectric, and the junction that is reflected in air dielectric and incidence surface 111 for the second time produces.Energy loss in the secondary reflection is learnt according to the Fresnel law:

The reflectivity of first reflection equals $R_P=\frac{n_K\cos {\mathrm{\θ}}_1-n_F\cos {\mathrm{\θ}}_2}{n_K\cos {\mathrm{\θ}}_1+n_F\cos {\mathrm{\θ}}_2},$ Reflectivity equals for the second time $R_s=\frac{n_K\cos {\mathrm{\θ}}_1-n_D\cos {\mathrm{\θ}}_2}{n_K\cos {\mathrm{\θ}}_1+n_D\cos {\mathrm{\θ}}_2},$ θ in the formula ₁Be incident angle, θ ₂Be refraction angle, n _FRefractive index, n for potting resin 121 _KRefractive index, n for air dielectric _DBe the refractive index of light guide plate 31, the total reflectivity that gets from formula equals $R=\frac{1}{2}(R_S+R_P),$ Transmitance L=1-R.

Suppose that light all is vertical incidence, promptly all θ are equal to 0 degree, n _FEqual 1.5, n _KEqual 1, n _DEqual at 1.5 o'clock, calculate in two secondary reflections total reflectivity and decrease R and equal 8%, promptly the energy loss of light is 8%, and this moment, transmitance L=1-R equaled 92%.If it is bigger that incident angle θ is not equal to the energy loss of 0, two secondary reflection, then can reduce the brightness of this module 1 backlight.

[summary of the invention]

In order to overcome big, the low problem of brightness of prior art module light ray energy loss backlight, the invention provides the module backlight that a kind of energy loss is little, brightness is higher.

The scheme that technical solution problem of the present invention is adopted is: a kind of module backlight is provided, and it comprises a light guide plate and at least one pointolite, and this light guide plate comprises the bottom surface of at least one incidence surface, an exiting surface and a relative exiting surface; The incidence surface setting of contiguous this light guide plate of this pointolite, its surface is surrounded by the potting resin that is used to protect pointolite, wherein between this pointolite and this incidence surface potting resin is arranged.

Compared to prior art, be provided with potting resin between the incidence surface of the light guide plate of the present invention's module backlight and the pointolite, be not have air dielectric between pointolite and the incidence surface, the refractive index of this potting resin is greater than the refractive index of air dielectric, notify the volume reflection that reduces light by calculating, the transmitance that promptly can increase light reduces the energy loss of light, thus the brightness that can improve module backlight.

[description of drawings]

Fig. 1 is the stereographic map of prior art module backlight.

Fig. 2 is the vertical view of module backlight shown in Figure 1.

Fig. 3 is the stereographic map of the present invention's module backlight.

Fig. 4 is the vertical view of module backlight shown in Figure 3.

[embodiment]

Seeing also Fig. 3 and Fig. 4, is the stereographic map and the vertical view of the present invention's module first embodiment backlight, and this module 3 backlight comprises a light guide plate 31 and a plurality of pointolite 32.This light guide plate 31 is plate shaped light guide plate, is to adopt transparent materials such as acryl, glass or polycarbonate to make, and it comprises exiting surface 312 and and exiting surface 312 opposed bottom surface 313 that an incidence surface 311 and this incidence surface 311 vertically link to each other.These a plurality of pointolites 32 equidistantly are arranged in incidence surface 311 1 sides of light guide plate 31; for protecting pointolite 32 not impaired; the surface of this pointolite 32 is surrounded by potting resin 321, and the pointolite 32 that it can be by disposing a plurality of different colours is to allocate required light source colour and brightness.The light that this pointolite 32 sends enters in the light guide plate 31 from the incidence surface 311 of this light guide plate 31, penetrates through the exiting surface 312 of the bottom surface of this light guide plate 31 313 reflections from this light guide plate 31.That is, the light transmission direction of these light guide plate 31 these pointolites 32 of guiding is converted into area source and penetrates.

Gapped between this pointolite 32 and this incidence surface 311, be when between pointolite 32 and this incidence surface 311 air dielectric being arranged, the light ray energy loss of this pointolite 32 is bigger, for reducing the energy loss of light, between this pointolite 32 and this incidence surface 311, be added with the potting resin 33 of different refractivity, between the incidence surface 311 with the potting resin 321 that prevents this pointolite 32 and this light guide plate 31 air dielectric arranged.First reflection produces in the junction of this potting resin 321 and potting resin 33, and the reflectivity of first reflection equals $R_P=\frac{n_T\cos {\mathrm{\θ}}_1-n_F\cos {\mathrm{\θ}}_2}{n_T\cos {\mathrm{\θ}}_1+n_F\cos {\mathrm{\θ}}_2},$ The junction that is reflected in for the second time potting resin 33 and this incidence surface 311 produces, and reflectivity equals for the second time $R_s=\frac{n_T\cos {\mathrm{\θ}}_1-n_D\cos {\mathrm{\θ}}_2}{n_T\cos {\mathrm{\θ}}_1+n_D\cos {\mathrm{\θ}}_2},$ The total reflectivity that gets from two formula equals $R=\frac{1}{2}(R_S+R_P),$ Transmitance L=1-R.By calculating down column data:

The refractive index n of working as potting resin as can be seen from the table _F, light guide plate 31 refractive index n _DBe constant 1.5, intermediate medium is a refractive index when being 1 air dielectric, and the transit dose L of light is minimum, and promptly the energy loss of light is maximum.When middle medium is the refractive index n of potting resin 33 and potting resin 33 _TMore near the refractive index n of potting resin _FOr the refractive index n of light guide plate 31 _D1.5 the time, the transmitance L of light is more near 1, and promptly the transit dose of light is many more, and energy loss is just few more, so, should make the refractive index n of potting resin 33 _KRefractive index n with potting resin _FOr the refractive index n of light guide plate 31 _DClose or identical, it can increase the transit dose of light, in other words can reduce the energy loss of pointolite 32 light, thereby improves the brightness of entire aphototropism mould 3.

Claims (8)

1. module backlight; comprise a light guide plate and at least one pointolite; this light guide plate comprises the bottom surface of an incidence surface, an exiting surface and a relative exiting surface; the incidence surface setting of contiguous this light guide plate of this pointolite; its surface is surrounded by the potting resin that is used to protect pointolite, it is characterized in that: be filled with potting resin between this pointolite and this incidence surface.

2. module backlight as claimed in claim 1 is characterized in that: the width of this potting resin is identical with the width of this incidence surface.

3. module backlight as claimed in claim 1 is characterized in that: the refractive index of this potting resin is identical with the refractive index of this potting resin.

4. module backlight as claimed in claim 1 is characterized in that: the refractive index of this potting resin is identical with the refractive index of this light guide plate.

5. module backlight as claimed in claim 1 is characterized in that: the refractive index of this potting resin is greater than the refractive index of air dielectric.

6. module backlight as claimed in claim 1 is characterized in that: incidence surface one side of this pointolite equidistantly to be arranged in this light guide plate.

7. module backlight as claimed in claim 1 is characterized in that: this light guide plate is plate shaped.

8. module backlight as claimed in claim 1 is characterized in that: this light guide plate is made by transparent materials such as acryl, glass or polycarbonate.

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