CN101046576A

CN101046576A - New LED back light module

Info

Publication number: CN101046576A
Application number: CNA200610066421XA
Authority: CN
Inventors: 刘敬伟; 王刚; 李俊峰; 任建昌; 王大巍; 孙润光
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2006-03-30
Filing date: 2006-03-30
Publication date: 2007-10-03
Anticipated expiration: 2026-03-30
Also published as: CN100587567C

Abstract

The new LED back light module includes LED units on a base plate, one casing and one light scattering and refracting mechanism with outer vertical plane as the outgoing plane. It features the partially reflecting and partially transmitting optical structure unit set in the light outgoing direction of the LED units and with structure independently to the LED units. The light from the LED' s is transmitted partially and scattered mostly in the optical structure unit so as to avoid LED shade spot in the light outgoing plane of the module. The optical structure unit may be regulated flexibly to reach proper ratio between the transmitted light and the scattered light. The present invention is suitable for various kinds of LED light source.

Description

A kind of new LED-backlit module

Technical field

The present invention is about a kind of LED (Light Emitting Diode) backlight module, particularly the LED-backlit module of the array of forming about a kind of optical texture unit with partial reflection and part transmission function.

Background technology

At present, LCD (LCD) has become the main flow in flat pannel display field.Because liquid crystal itself is not luminous, so LCD need realize that transmission or reflection show by external light source.Existing LCD great majority are transmission-types, and for these transmission-types LCD, backlight is indispensable ingredient.

With respect to traditional cold cathode fluorescent lamp (CCFL), with LED be that the backlight module of light source has that color reducibility is good, advantage such as power saving, good environmental adaptability, pollution are little.Adopt the LCD of LED-backlit can show chromatic colour more, its color rendition scope can reach more than 105% of NTSC, be higher than far away CCFL backlight 75%.As the light source of full curing, LED has very strong environmental suitability.What is more important, CCFL contains the mercury metal that environment is had significant damage, and then there is not the problem of this respect in LED.Though at present the price of LED-backlit is than the CCFL height, and according to rule in the industry, per 10 years prices of LED descend about 10 times and performance improves about 20 times.Can predict, about 2008, LED will replace CCFL gradually and become the backlight source of main flow.

The most general in the market LED as shown in Figure 1.This class LED is a top light emitting, and promptly light is optical axis with the top normal L of light-emitting area (some light-emitting area is a sphere), and light concentrates on upwards emission in certain angle (as ± 60 °) scope.If according to known backlight technology, directly adopt this class white light LEDs to make as shown in Figure 3 direct-light-type backlight, on exiting surface, be easy to occur the lamp shadow hot spot.In order to eliminate hot spot, often need to widen exiting surface to the distance between LED, thereby increase the thickness of backlight greatly.If adopt red bluish-green (R G B) three-color LED to make light source, by the colour mixture synthesize white light, so above-mentioned common LED is owing to emission angle is too upwards concentrated the effect that is difficult to reach mixed light.In order to overcome the above-mentioned shortcoming of common LED, LED-backlit LED that adopt in the source as shown in Figure 2 at present.On the exiting surface of this class improvement LED, a hemispherical lens and back taper catoptron have been added, the light that sends of LED is just by original top-emission like this, changed side-emitted into, being that 80 ° light path is the strongest luminous position with normal L angle both, is main light-emitting area in ± 20 ° angle.Side-emitting ledly not only can well eliminate the lamp shadow hot spot, and help R G the mixing of B three coloured light.Utilize this class LED to produce the direct LED backlight of thinner thickness.But owing to be added with and incorporate hemispherical lens of LED and back taper catoptron, making this class backlight special LED need be through accurate and complicated technology, and manufacture difficulty is big and cost is high.In addition, because LED, hemispherical lens and back taper catoptron are produced on together, greatly reduce the degree of freedom in the optical design.All above-mentioned shortcomings have all hindered applying of LED-backlit technology to a certain extent.Therefore, press for a kind of general commercial LED that can either be applicable to as shown in Figure 1 in the industry, and make the backlight technology simple, that design freedom is high.

Summary of the invention

The present invention seeks to defective, provide a kind of and can be applicable to most general commercial at prior art, and low, the easy realization of cost, LED-backlit module that design freedom is high.

In order to achieve the above object, the invention provides a kind of new LED-backlit module, comprise, the LED luminescence unit, shell, light scattering and refraction means, the LED luminescence unit is installed on the substrate, the outer facade of light scattering and refraction means is an exiting surface, it is characterized in that: the light output direction of LED luminescence unit is provided with the optical texture unit of partial reflection and part transmission function, and structurally discrete with the LED luminescence unit.

Wherein, each the LED luminescence unit in the described led array can be single or one group of white light LEDs, or single or one group of R G B LED.Described optical texture unit can be for one or more, and the optical texture unit is corresponding with the LED luminescence unit.Described optical texture cell surface is shaped as nonplanar structure, as taper or sphere etc.Described optical texture unit also can be Fresnel Lenses.In addition, can be added with other optical textures such as diffusion barrier or prism film between described LED unit and the optical texture unit.Described side wall of outer shell and plate inner wall card are with the reflection horizon.Light scattering and refraction means are made up of some diffusion barriers (plate) and prism film optical textures such as (Prism Sheet).

The invention provides the array of optical texture unit composition with partial reflection and part transmission function, its ranks number is corresponding with led array, the optical texture cell array can be made up of a plurality of nonplanar reflecting surface with partial reflection part transmission function that is placed on the transparency carrier, top, unit in each led array is all to there being this reflecting surface, like this, the light that comes out from each LED top-emission, a part sees through the back and continues to propagate, another part is reflexed to periphery and base plate by an on-plane surface reflecting surface, after periphery and base plate reflection, launch from exiting surface, so just avoided the appearance of lamp shadow hot spot on the module exiting surface.

One group of LED that the present invention adopts a plurality of LED that closely are arranged in together to form helps luminescence efficiency between the average LED and the difference between the light intensity attenuation, also help R G B LED send monochromatic mixing.

The present invention is because optical texture cell array and LED structurally are independently, so can separately make, the optical texture cell array just can be complementary with various LED like this.At first, the parameter of optical texture unit can be regulated easily; Secondly, pairing LED unit, each optical texture unit can be a LED, also one group of LED that can be made up of a plurality of LED; At last, can add other optical textures such as diffusion barrier (plate) or prism film in addition between optical texture cell array and led array, these measures that can select flexibly all help the effect of astigmatism.These advantages have all improved the degree of freedom in the backlight module optical design greatly,

In a word, the present invention can provide a kind of can either be applicable to general commercial LED, realizes the backlight technology that design freedom is high again again easily.Manufacture craft of the present invention is simple, and cost is very low, is very beneficial for improving the competitive power of industry.

Description of drawings

Fig. 1 is common top-emission LED;

Fig. 2 is side-emitted LED;

Fig. 3 is known LED-backlit module side cross section view;

Fig. 4 is a LED-backlit module side cross section view of the present invention;

Fig. 5 is another embodiment of the present invention side cross section view;

Fig. 6 is another embodiment of the present invention side cross section view;

Fig. 7 a is the led array vertical view of arranging in another embodiment of the present invention;

Fig. 7 b is a LED layout viewing in the led array unit;

Fig. 7 c is the led array unit surface of intensity distribution.

The drawing reference numeral explanation:

L, normal; A, arrow; R, light;

1, led array; 13, the led array unit of forming by a plurality of LED;

21, outer casing bottom; 22, side wall of outer shell; 23, outer casing bottom reflectance coating; 24, side wall of outer shell reflectance coating; 3, light scattering and refraction means;

41, taper half-reflecting half mirror; 42, taper half-reflecting half mirror array base palte; 43, Fresnel Lenses;

5, diffusion barrier (plate)

Embodiment

Embodiment one: Figure 4 shows that a LED-backlit module embodiment provided by the present invention.The light scattering and the refraction means 3 that shell, led array 1, taper half-reflection and half-transmission lens array 41 are wherein arranged, form by some diffusion barriers (plate) and prism film.

Dug and led array 1 corresponding array of orifices at outer casing bottom 21, led array 1 just is installed in this array of orifices, and light scattering and refraction means 3 are installed in the module top, and its upper surface is exactly the exiting surface of module.The material of shell can be metal materials such as aluminium alloy etc.Used LED is highlighted top-emission White LED, and the white light emission mechanism of this LED can be by excitated fluorescent powder emission white light, also can be R G B be mixed into white light.

Post outer casing bottom reflectance coating 23 and side wall of outer shell reflectance coating 24 at the place and the side wall of outer shell of outer casing bottom 21 inwalls except that aperture, reflectance coating can be minute surface transmitting film or diffusive reflective film.Same technique known (Fig. 3) is compared, between led array 1 and light scattering and refraction means 3, add a taper half-reflection and half-transmission lens arra, this array is by being arranged in that a plurality of taper half-reflecting half mirrors 41 on the taper half-reflecting half mirror array base palte 42 are formed and corresponding one by one with the luminescence unit of led array, the half-reflecting half mirror 41 of this taper also can be the device of other nonplanar partial reflections and part transmission, as sphere or class sphere.Taper half-reflecting half mirror array base palte 42 can be the good inorganic or organic materials of various light transmissions, as optical quartz glass, acryl material etc.A concrete method for making of tapered lens 41 can be: utilize mould to produce cone-shaped body on substrate, stick the half-reflection and half-transmission blooming on the cone-shaped body surface then.

Light scattering and refraction means 3 are made up of some known diffusion barriers (plate) and prism film.

Embodiment two: as shown in Figure 5, on the basis of specific embodiment one, improved, add one diffusion barrier (plate) 5 between led array 1 and taper half-reflection and half-transmission lens array, wherein diffusion barrier (plate) 5 also can be prism film or other bloomings and their combination.

Embodiment three: as shown in Figure 6, different with specific embodiment one is that the optical texture unit with partial reflection and part transmission function is a Fresnel Lenses 43.Fresnel Lenses can utilize known knowledge, utilizes the method for injection mo(u)lding to make at an easy rate.

Embodiment four: as shown in Figure 7, on the basis of above-mentioned specific embodiment one to embodiment three, improved, used LED11 is miniwatt top-emission LED in the foregoing description, and this LED11 can be white luminous LED, also can be launch separately R G the monochromatic LED of B.Be one group with a plurality of LED in the present embodiment, form the led array 1 shown in Fig. 7 a.The evenly distributed mode of such arrangement and all LED is compared following advantage: because the luminous characteristics of each LED all has difference (comprising luminous intensity difference own and later stage light intensity attenuation difference), be a led array unit 13 with a plurality of LED so, the average difference of each LED, the general performance of every group of LED more single led 11 is more uniform and stable; LED closely is arranged in one group, help R G the monochromatic abundant mixing of B.The led array unit 13 that Fig. 7 b is made up of 16 LED, Fig. 7 c is the light effect that of this unit, as seen, a such led array unit 13 sends the light intensity distribution and a great power LED sends the light intensity distributional class seemingly.So just can utilize the similar structures design backlight module among the embodiment one to embodiment three.

The structure of LED in the various embodiments described above is applicable to various LED encapsulating structures, as the lateral emitting formula; In addition, the quantity of the quantity of LED luminescence unit and each luminescence unit LED and color are selected; The quantity and the structure of the optical texture unit of partial reflection and part transmission function all can carry out freely designing according to the optical demands of reality.

More than explanation and accompanying drawing have provided specific implementations of the present invention, but it is self-evident, the present invention can carry out various distortion by those skilled in the art and implement, as change the structural design of LED, change quantity and the distribution situation of LED, change the structure of partial reflection and part transmission optics structural unit etc.The embodiment that has been out of shape like that etc. can not break away from technological thought of the present invention or prospect is individually understood, and must regard the structure that comprises in the appending claims of the present invention as.

Claims

1, a kind of new LED-backlit module, comprise, the LED luminescence unit, shell, light scattering and refraction means, the LED luminescence unit is installed on the substrate, and the outer facade of light scattering and refraction means is an exiting surface, it is characterized in that: the light output direction of LED luminescence unit is provided with the optical texture unit of partial reflection and part transmission function, and structurally discrete with the LED luminescence unit.

2, according to right 1 described a kind of new LED-backlit module, it is characterized in that: described LED luminescence unit can be for one or more, and each unit in the LED luminescence unit can be made up of single or multiple LED.

3, according to right 2 described a kind of new LED-backlit modules, it is characterized in that: described optical texture unit can be for one or more.

4, a kind of new LED-backlit module according to claim 3, it is characterized in that: described optical texture unit is corresponding with the LED luminescence unit.

5, according to the arbitrary described a kind of new LED-backlit module of claim 1 to 4, it is characterized in that: described optical texture cell surface is shaped as nonplanar structure.

6, a kind of new LED-backlit module according to claim 5, it is characterized in that: described nonplanar structure is taper or sphere.

7, according to the arbitrary described a kind of new LED-backlit module of claim 1 to 4, it is characterized in that: described optical texture unit is a Fresnel Lenses.

8, according to the arbitrary described a kind of new LED-backlit module of claim 1 to 4, it is characterized in that: between described LED luminescence unit and the optical texture unit other optical textures are arranged.

9, a kind of new LED-backlit module according to claim 8, it is characterized in that: described other optical textures can be diffusion barrier or prism film.

10, according to the arbitrary described a kind of new LED-backlit module of claim 1 to 4, it is characterized in that: described side wall of outer shell and plate inner wall have the reflection horizon.