CN1421727A - Multiple-angle reflecting plate for back lighting module - Google Patents

Abstract

The back lighting assembly includes several light tubes, one diffusing plate and one multiple-angle reflecting plate. The multiple-angle reflecting plate includes one substrate and several reflecting lugs, the substrate has one top side towards the light tubes, and each of the reflecting lugs on the substrate has one reflecting surface with several different reflecting angles to reflect the light from the light tubes to the diffusing plate. According to practical requirement, the multiple-angle reflecting plate may be regulated in its reflecting angle to raise light homogeneity. The reflecting lugs may be very small to reduce the thickness of the multiple-angle reflecting plate.

Description

The multiple-angle reflecting plate that is used for direct type backlight module

Technical field

The present invention relates to a kind of backlight module, in detail, is the multiple-angle reflecting plate that is used for direct type backlight module about a kind of.

Background technology

With reference to figure 1, be the direct type backlight module synoptic diagram of Japanese kokai publication hei 05-323312 patent, this backlight module 1 comprises a plurality of fluorescent tubes 11, a diffuser plate 12 and a reflecting plate 13.This backlight module 1 is arranged in the below of LCD liquid crystal board.This fluorescent tube 11 can be fluorescent tube, in order to light source to be provided.This diffuser plate 12 is arranged at the top of this fluorescent tube 11, its material be generally polymethylmethacrylate (polymethylmetharylate, PMMA) or polycarbonate (polycarbonate, PC), the light in order to this fluorescent tube 11 is dispersed diffuses to liquid crystal board.This reflecting plate 13 is arranged at the below of this fluorescent tube 11, its material is reflection-type polycarbonate commonly used or polyoxyethylene terephthalic acids (polyethylene terephthalate, PET) reflecting plate reflexes to diffuser plate 12 in order to the light that this fluorescent tube 11 is dissipated into backlight module 1 bottom.

This direct type backlight module 1 is because of having this fluorescent tube 11 that directly places these diffuser plate 12 belows, thus its briliancy height, and because of simple in structure, compare with the backlight module of other kinds form, have lightweight advantage.In addition, there is no veil on the diffuser plate of direct type backlight module, when the user watched, it is bigger that the visual angle of screen is also felt.But then, because fluorescent tube 11 area just above because of light is directed to this diffuser plate 12, make this zone brighter, and on the contrary, the position, top is then darker between fluorescent tube and fluorescent tube, so the reflecting plate 13 of this backlight module 1 is quite important for the light uniformity coefficient.Simultaneously also because of this direct type backlight module 1 needs reflecting plate 13 light is reflexed to this diffuser plate 12, the shared space of this reflecting plate 13 is quite big, so the thickness of this direct type backlight module 1 is bigger.

In addition, the manufacturing because existing this reflecting plate 13 is formed in one, its reflection angle and all fixing with the relative distance of fluorescent tube 11, can't elasticity be adjusted the reflection angle of this reflecting plate 13 according to brightness, number and the relative distance of actual fluorescent tube, therefore can't reflect uniform light to this diffuser plate 12.

So be necessary to provide the multiple-angle reflecting plate of a kind of innovation and rich progressive, to address the above problem.

Summary of the invention

In order to overcome the deficiencies in the prior art, the object of the present invention is to provide a kind of multiple-angle reflecting plate that is used for direct type backlight module that has uniform distribution of light and improve light utilization efficiency.

Another object of the present invention is to provide a kind of multiple-angle reflecting plate that is used for direct type backlight module that reduces backlight module thickness.

In order to achieve the above object, the invention provides a kind of multiple-angle reflecting plate that is used for direct type backlight module, wherein this backlight module comprises a plurality of fluorescent tubes, a diffuser plate and a multiple-angle reflecting plate.This diffuser plate is arranged at the top of this fluorescent tube, and this multiple-angle reflecting plate is arranged at the below of this fluorescent tube.This multiple-angle reflecting plate comprises: a base plate and a plurality of reflection projection.This base plate has an end face towards this fluorescent tube.This reflection projection is formed on the end face of this base plate, and respectively this reflection projection has a reflecting surface, and this reflecting surface has a plurality of different reflection angles, so that reflex to this diffuser plate from the light of this fluorescent tube according to this reflection angle.

Therefore, utilize multiple-angle reflecting plate of the present invention can cooperate the distance of the number and the inter-module of fluorescent tube, flexibly to adjust the reflection angle that respectively should reflect the reflecting surface of projection, make the various design reflectivity of light foundation to this diffuser plate, to have uniform distribution of light and to improve light utilization efficiency.Because the volume that reflects projection that is somebody's turn to do of the present invention is quite little, this multiple-angle reflecting plate can be done quite thinly, so shared space is quite little simultaneously.So generally speaking, will the thickness of backlight module of the present invention relatively be reduced.

Description of drawings

The present invention is described in detail below in conjunction with drawings and Examples:

Fig. 1 is the section partial schematic diagram of existing backlight module;

Fig. 2 a is the section partial schematic diagram of the backlight module of first embodiment of the invention;

Fig. 2 b to 2c is the angle calculation synoptic diagram of backlight module of the present invention;

Fig. 3 is the section partial schematic diagram of the backlight module of second embodiment of the invention; And

Fig. 4 is the section partial schematic diagram of the backlight module of third embodiment of the invention.

Symbol description among the figure:

1 existing direct type backlight module

11 fluorescent tubes

12 diffuser plates

13 reflecting plates

The direct type backlight module of 2 first embodiment of the invention

21 fluorescent tubes

22 diffuser plates

23 multiple-angle reflecting plates

231 base plates

232,233 reflection projections

235 end faces

236,237 reflectings surface

The direct type backlight module of 3 second embodiment of the invention

31 fluorescent tubes

32 diffuser plates

33 multiple-angle reflecting plates

331 base plates

332,333 reflection projections

336,337 reflectings surface

The direct type backlight module of 4 third embodiment of the invention

41 fluorescent tubes

42 diffuser plates

43 multiple-angle reflecting plates

431 base plates

432,433 reflection projections

Embodiment

With reference to figure 2a, first embodiment of the present invention direct type backlight module 2 comprises a plurality of fluorescent tubes 21 (only showing among the figure that a fluorescent tube 21 explains), a diffuser plate 22 and a multiple-angle reflecting plate 23.This diffuser plate 22 is arranged at the top of fluorescent tube 21.This multiple-angle reflecting plate 23 is arranged at the below of fluorescent tube 21, reflexes to this diffuser plate 22 in order to the light that fluorescent tube 21 is dissipated into backlight module 2 bottoms.

This multiple-angle reflecting plate 23 comprises: a base plate 231 and a plurality of reflection projection 232,233 etc.This base plate 231 has an end face 235 towards fluorescent tube 21.Reflection projection 232,233 compartment of terrains are formed on the end face 235 of this base plate 23.Each reflection projection 232,233 has a reflecting surface 236,237 respectively.The reflecting surface 236 of reflection projection 232 has different degree of tilt with the reflecting surface 237 of reflection projection 233, so for the reflection angle difference of light.

Because fluorescent tube 21 is different with the relative distance of each reflection projection, and fluorescent tube 21 is incident to the incident angle difference of this reflecting surface.If the degree of tilt of this reflecting surface is all identical, then can't reflect uniform light to this diffuser plate.Therefore, the present invention designs the degree of tilt difference of this reflection projection, to adapt to the difference of relative distance and incident angle.So can make light reflex to diffuser plate 22 equably according to reflection angle from fluorescent tube 21.

With reference to figure 2b, be example with reflection projection 232.Fluorescent tube 21 is a apart from the vertical height distance of the reflecting surface 236 of this reflection projection 232, fluorescent tube 21 is c apart from the horizontal range of reflection projection 232, the incident ray of fluorescent tube 21 and horizontal angle are α, the angle of the reflecting surface 236 of this reflection projection 232 is θ, if wish to get reflection ray after the reflection perpendicular to this end face 235, then being calculated as follows of the angle θ of reflecting surface 236: ∠ 3=∠ θ $\∠1=\frac{\mathrm{\π}}{2}-\∠\mathrm{\α}-\∠\mathrm{\θ}$ $\frac{\mathrm{\π}}{2}-\∠\mathrm{\α}=\∠1+\∠2$ $=2(\frac{\mathrm{\π}}{2}-\∠\mathrm{\α}-\∠\mathrm{\θ})$

$=\mathrm{\π}-2\∠\mathrm{\α}-2\∠\mathrm{\θ}$ $\∠\mathrm{\θ}=\frac{\mathrm{\π}}{4}-\frac{1}{2}\∠\mathrm{\α}$ $=\frac{\mathrm{\π}}{4}-\frac{1}{2}{\mathrm{Tan}}^{-1}\frac{a}{c}$

Shown in figure 2c, if when needing design to make the angular deflection β angle of reflection ray, then according to twice angle principle, the angle θ of reflecting surface must with minimizing Angle.

Therefore, be the reflecting surface of the reflection projection of c in distance fluorescent tube 21 vertical heights apart from a and horizontal range, when being β as if the angle that will obtain reflection ray, then the angle θ according to above-mentioned this reflecting surface of calculating must be designed to $\∠\mathrm{\θ}=\frac{\mathrm{\π}}{4}-\frac{1}{2}{\mathrm{Tan}}^{-1}\frac{a}{c}-\frac{\mathrm{\β}}{2}$

Wherein, the β value then is counterclockwise, if the β value is that negative is then for clockwise if being positive number.

Therefore, according to the angle beta of required reflection ray, apart from the vertical height of fluorescent tube 21 apart from a and horizontal range c, can calculate the reflecting surface angle of each reflection projection, make from the light of this fluorescent tube 21 and reflex to this diffuser plate 22 according to the needs of reality.

This multiple-angle reflecting plate 23 can utilize the plastics ejection formation to make this base plate 231 and a plurality of reflection projection 232,233 etc., and coating one has the reflection horizon of reflecting material on this reflecting surface 236,237 again, and this reflection material can be metals such as aluminium, silver.This multiple-angle reflecting plate 23 also can utilize the electroforming mode directly to make the sheet metal with a plurality of reflection projections.In addition, also can make this metallic reflection plate have a plurality of reflection projections directly to a metallic reflection plate machine-shaping.

Because the reflection projection of multiple-angle reflecting plate 23 of the present invention has different reflection angles, therefore utilize multiple-angle reflecting plate 23 of the present invention can cooperate fluorescent tube 21 number and with the relative distance of fluorescent tube 21, flexibly to adjust the reflection angle that respectively should reflect the reflecting surface of projection, make the various design reflectivity of light foundation to this diffuser plate, be distributed to this diffusion version to obtain designed uniform light.

In addition, because the volume of reflection projection 232,233 of the present invention is quite little and be formed at the end face 235 of this base plate 231.Compared to the reflecting plate 13 of Fig. 1, the thickness of multiple-angle reflecting plate 23 of the present invention can be done quite thinly, so shared space is quite little.So generally speaking, will the integral thickness of backlight module 2 of the present invention relatively be reduced.

With reference to figure 3, the direct type backlight module 3 of second embodiment of the invention comprises a plurality of fluorescent tubes 31, a diffuser plate 32 and a multiple-angle reflecting plate 33.This multiple-angle reflecting plate 33 comprises: a base plate 331 and a plurality of reflection projection 332,333 etc.Reflection projection 332,333 designs of this multiple-angle reflecting plate 33 make the light that reflexes to diffuser plate 32 concentrate.These reflection projection 332,333 bulks roughly triangular in shape, the reflecting surface 336,337 of reflection projection 332,333 is a hypotenuse plane of this triangle bulk.

With reference to figure 4, the direct type backlight module 4 of third embodiment of the invention comprises a plurality of fluorescent tubes 41, a diffuser plate 42 and a multiple-angle reflecting plate 43.This multiple-angle reflecting plate 43 comprises: a base plate 431 and a plurality of reflection projection 432,433 etc.The feasible divergence of beam that reflexes to this diffuser plate 42 of reflection projection 432,433 designs of this multiple-angle reflecting plate 43.

Therefore, multiple-angle reflecting plate of the present invention has high design flexibility, can adjust the reflection angle of this reflection projection according to different elasticity of demand, to adapt to various actual needs.

The foregoing description only is explanation principle of the present invention and effect thereof, and unrestricted the present invention.Therefore, those skilled in the art can make amendment to the foregoing description without prejudice to spirit of the present invention and change.Protection scope of the present invention with claims and in conjunction with instructions and accompanying drawing the person of being defined be as the criterion.

Claims (7)

1. multiple-angle reflecting plate that is used for direct type backlight module, wherein this backlight module comprises a plurality of fluorescent tubes and a diffuser plate, and this diffuser plate is arranged at the top of fluorescent tube, and this multiple-angle reflecting plate is arranged at the below of fluorescent tube, and multiple-angle reflecting plate comprises:

One base plate has an end face towards fluorescent tube;

A plurality of reflection projections are divided on the end face of this base plate, and each reflects projection and has a reflecting surface, and reflecting surface has a plurality of different reflection angle with respect to plate top surface, so that reflex to diffuser plate from the light of fluorescent tube according to different reflection angles.

2. multiple-angle reflecting plate according to claim 1 is characterized in that: each reflects coating one reflection horizon on the reflecting surface of projection.

3. multiple-angle reflecting plate according to claim 1 is characterized in that: each reflects projection and has cross section roughly triangular in shape, and this reflecting surface is one side of triangular-section.

4. multiple-angle reflecting plate according to claim 1 is characterized in that: each reflecting surface that reflects projection is a plane.

5. multiple-angle reflecting plate according to claim 1 is characterized in that: each reflects projection makes the light that reflexes to diffuser plate vertical substantially with the end face of base plate.

6. multiple-angle reflecting plate according to claim 1 is characterized in that: each reflects projection is that the light that reflexes to this diffuser plate is concentrated.

7. according to the described multiple-angle reflecting plate of claim 1, it is characterized in that: each reflects projection is to make the divergence of beam that reflexes to this diffuser plate.

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