Background technology
With critical elements and the brightness source of backlight, extremely important for improving liquid crystal display brightness as the LCD Presentation Function.Before the present invention, industry has been attempted multiple mode and has been removed to improve the LCD display brightness from the backlight module aspect, for example, adjusts from lamp source side face, by increasing the fluorescent tube number and/or increasing the lamp source power, just can face the big and power consumption of volume shortcoming such as how to improve display brightness.
Good reflector plate the more important thing is that except increasing the brightness brightness promotes to comprehensive raising, can not dwindle the visual angle, through the reality test, increases the reflectivity of 3-5%, just can make same module promote the brightness of 8-10% under equal state.
In addition, the LCD product is by past notebook computer or the LCD monitor LCD TV that expands, and the subject matter of being considered is that enough video picture brightness must be able to be arranged, broad watch visual angle, distinct picture contrast and standardized serviceable life.For reaching the demand, therefore " direct-light-type backlight module " (Direct Type Backlight) just becomes the technology main flow of present collocation large LCD TV, and the structure of direct-light-type backlight module as shown in Figure 1.
The direct-light-type backlight module product has high brightness usually, produces but the fluorescent tube number becomes many situations that present the light and shade striped that but cause easily, and the uniformity coefficient of light is had to a certain degree influence.And reflector plate is the plane, and when by the incident angle deflection of the incident light of panel top incident, catoptrical direction also can depart from the panel front direction, causes the front face brightness deficiency easily.
For improving above-mentioned shortcoming; there is the technology of using light diffusing sheet; for example the Jap.P. spy opens 2000-11886 number announcement; in glass baseplate surface with the metal etch alligatoring; make the reflecting plate surface have concaveconvex shape; this patent must be protected for avoiding glass substrate back side contact etch liquid, thereby the processing procedure trouble, and the follow-up difficult processing of etching solution.
In addition, also exist and utilize photoresist to make its metal form the film with concaveconvex shape with the little shadow technology of light shield, form the scattered reflection film in the surface, but, utilize the little shadow technology of light shield, processing procedure is expensive and wayward.
This case the inventor find through broad research, directly has the film of concave-convex micro-structure in the reflector plate surface-coated, the simple control easily of processing procedure, and good with the substrate adherence, can effectively solve the aforesaid drawbacks.
Embodiment
Object is in catoptrical process, because its surface structure difference, and can produce multi-form reflection.Reflection of light comprises direct reflection and two kinds of forms of scattered reflection.As shown in Figure 2, when ray cast presents regular reflection on smooth surface, hard object, be called direct reflection.And as shown in Figure 3, when ray cast presents irregular reflection on shaggy object, be called scattered reflection.
Reflector plate of the present invention is for reaching light scattered reflection effect, and has concave-convex micro-structure at least one surface of its base material.For there is no particular restriction for the method that forms described concave-convex micro-structure, it can form by the known any way of one of ordinary skill in the art.Preferred mode has the coating of concave-convex micro-structure for applying at substrate surface, and this coating has the ability that light can be spread, and comprises particle and the cement of diameter 1 μ m to 50 μ m.For reaching diffusion effect, institute's metal particles is preferably 10-200 weight % with respect to the amount of cement, is preferably 30-60 weight %.Be lower than 10 weight % as fruit granule with respect to the amount of cement, diffusion effect is bad so; If but were higher than 200 weight %, particle would be difficult to be fixed in the cement of substrate surface and could produce the misgivings that come off so.There is no particular restriction for the particle that can be used among the present invention, it can be organic filler, inorganic particulate or both potpourris.The coating of particles of using does not have particular restriction yet, for example sphere, rhombus etc.
The organic filler that can be used among the present invention is to be selected from the group that is made of acryl resin, styrene resin, carbamate resins, silicone resin (silicone) and composition thereof.
The inorganic particulate that can be used among the present invention is to be selected from the group that is made of zinc paste, silicon dioxide, titania, zirconia, aluminium oxide, zinc sulphide, barium sulphate and composition thereof.
According to a specific embodiment of the present invention, above-mentioned particle is preferably between 1 μ m to the organic filler between the 10 μ m, and preferred organic filler is the silicone resin particle.
Above-mentioned cement there is no particular restriction, it for example is selected from the group that acryl resin, polyamide, epoxy resin, fluoroplast, polyimide resin, polyurethane resin, alkyd resin (alkydresin), vibrin and composition thereof are constituted, and is preferably acryl resin, polyurethane resin, vibrin or its potpourri.The cement that is used for the present invention, owing to must allow light see through, it is preferably water white cement.The present invention has the base material that reflector plate comprised of reflex, there is no particular restriction, can be transparent, translucent or opaque base material.Generally speaking, this base material comprises at least one floor height molecule resin.There is no particular restriction for above-mentioned macromolecule resin, it is such as but not limited to polyalkenes resin (polyolefin resin), as tygon (PE) or polypropylene (PP); Vibrin (polyester resin) is as polyethylene terephthalate (PET); Polyacrylate (polyacrylate resin) resin is as polymethylmethacrylate (PMMA); Polycarbonate resin (polycarbonate resin); Polyurethane resin (polyurethane resin) or its potpourri.According to an advantageous embodiment of the invention, reflector plate of the present invention uses the vibrin base material, is preferably polyethylene terephthalate.Base material of the present invention can optionally comprise the known inorganic particles of one of ordinary skill in the art, and its (for example) is zinc paste, silicon dioxide, titania, aluminium oxide, calcium sulphate, barium sulphate, lime carbonate or its potpourri.Be preferably titania or barium sulphate.The reflecting effect of reflector plate of the present invention mainly is macromolecule resin or the inorganic particles that utilizes foaming, and base material of the present invention can be multilayer, and wherein the middle layer is described macromolecule resin, and it can foam or not foam, or the middle layer contains inorganic particles.
The employed coating with concave-convex micro-structure of light diffusion reflection sheet of the present invention generally has the thickness between 1-50 μ m, preferably has the thickness of 2-15 μ m.For avoiding the macromolecule resin yellow in the reflector plate base material, cause reflecting effect to weaken aberration problem with LCD, can optionally inorganics be made an addition in the coating.For being applicable to that the inorganics kind in the coating of the present invention there is no particular restriction, only need having the ultraviolet ability of absorption and get final product.Its (for example) but be not limited to zinc paste, massicot, aluminium oxide, silicon dioxide, titania, calcium sulphate, barium sulphate, lime carbonate or its potpourri.The particle size of above-mentioned inorganics is generally 1 to 100 nanometer, and (nanometer nm), is preferably 20nm to 50nm.
The coating of reflector plate substrate surface of the present invention can optionally comprise one of ordinary skill in the art's known additives, its (for example) but be not limited to leveling agent, stabilization agent, rigidizer, fluorescer or ultraviolet light absorber.
Can be used for rigidizer of the present invention (Curing Agent) can produce molecule and intermolecular chemical bond with cement and form crosslinked (Crosslinking), this is that one of ordinary skill in the art are known, and it for example is a polyisocyanate (Polyisocyanate).
There is no particular restriction for can be used for fluorescer of the present invention, for one of ordinary skill in the art known, it can be organism, such as but not limited to the two triazines (diphenylethylenebistriazines) of benzoxazoles class (benzoxazoles), benzimidazole (benzimidazoles) or talan; Or inorganics, for example zinc sulphide.
Can be used for ultraviolet light absorber of the present invention is that one of ordinary skill in the art are known, and it for example is benzotriazole (benzotriazoles), phentriazine class (benzotriazines), Benzophenone class (benzophenones) or salicyclic acid derivatives (salicylic acid derivatives) etc.
Reflector plate of the present invention can provide the reflectivity that reaches more than 97% in visible light wave zone 400 μ m-780 μ m, can effectively improve brightness of backlight module.
Glossiness (Gloss) is that whether smooth many more from the light of body surface reflection, the performance of glossiness is obvious more in order to assessment body surface visual phenomenon.Surface of the present invention has the reflector plate of concave-convex micro-structure, its surface gloss, and according to ASTM D523 standard, as shown in Figure 4, when light source throwed with 60 ° of incident angles, the glossiness that records was lower than 10%.
Reflector plate of the present invention has good light diffusion effect, and it can goniophotometer be measured its surface reflectivity parameter distributions situation and is confirmed, and generally can obtain in the direct reflection direction stronger reflection potential being arranged shown in Fig. 5 a near smooth plane.But shown in Fig. 5 b, reflector plate of the present invention has concave-convex micro-structure because of its surface, but thereby the careless and sloppy reflection of light one way or another.
Reflector plate of the present invention has good weatherability, and have and absorb ultraviolet effect, and because the surface has concave-convex micro-structure, but scattered reflection light easily obtains uniform visual angle, and therefore reflector plate of the present invention is applicable in the backlight module (back light module) of flat-panel screens, especially direct-light-type backlight module, can make reflected light diffusion homogenising as light diffusion reflection sheet, eliminate the light and shade fringe phenomena, reach uniformity coefficient.
Following examples will the present invention is described further, just is not in order to limiting the scope of the invention, and any one of ordinary skill in the art are all belonging to scope of the present invention without prejudice to following modification that is realized of the prerequisite of spirit of the present invention and variation.
Example:
Embodiment 1
With 68.1 gram acryl resin (Eterac 7363-ts-50, Eternal provides) (solid part about 50%), add in the plastic bottle, (Tospearl 145 to add each 52.0 gram of MEK and toluene, mean grain size more in regular turn and be silicone resin pearl powder 50.0 gram of 4 μ m under high-speed stirred, GE Toshibasilicones provides), 1-100nm zinc paste, titania and barium sulphate totally 10.0 grams, (Desmodur 3390 just to add rigidizer at last, Bayer provides) 6.6 grams, infusion becomes solid part about 40%, the about 250.0 gram coating of gross weight.With paint daubs coating is coated on UX-150 (Teijin provides) base material, can about 10 μ m after the drying film left standstill and done weather resistance test (utilizing the weather-proof accelerated testing cabinet of QUV, Q-panel company) after 7 days.The result is as shown in table 1 below for the test gained.And survey its luminosity as shown in Figure 6.
Embodiment 2
Repeat the step of embodiment 1, just change base material UX-150 (Teijin provides) into E60L (Toray provides).The result is as shown in table 1 below for the test gained.
Comparative example 1
Acryl resin (Eterac 7363-ts-50, Eternal provides) (solid part about 50%) 145.9 grams are added in the 250 gram plastic bottles, under high-speed stirred, add each 38.0 gram of MEK and toluene more in regular turn; About altogether 10.0 grams of 1-100nm level zinc paste, titania and barium sulphate; Just add rigidizer (Desmodur 3390, and Bayer provides) 14.1 gram at last, infusion becomes solid part about 40%, the about 250.0 gram coating of gross weight.With paint daubs coating is coated on UX-150 (Teijin) base material, can about 10 μ m after the drying film left standstill after 7 days and done physical property measurement, and the result is as shown in table 1 below for the test gained.
Comparative example 2
Repeat the step of comparative example 1, just change base material UX-150 (Teijin provides) into E60L (Toray provides).The result is as shown in table 1 below for the test gained.
Comparative example 3
With 68.1 gram acryl resin (Eterac 7363-ts-50, Eternal provides) (solid part about 50%) add in the plastic bottle, (Tospearl 145 to add each 52.0 gram of MEK and toluene and silicone resin pearl powder 50.0 grams again under high-speed stirred in regular turn, GE Toshibasilicones provides), (Desmodur 3390 to add rigidizer afterwards, Bayer provides) 6.6 grams, infusion becomes solid part about 40%, the about 250.0 gram coating of gross weight.With paint daubs coating is coated on UX-150 (Teijin provides) base material, does weather resistance test (utilizing the weather-proof accelerated testing cabinet of QUV, Q-panel company) after can about 10 μ m after the drying film left standstill after 7 days.The result is as shown in table 1 below for the test gained.
Comparative example 4
Repeat the step of comparative example 3, just change base material UX-150 (Teijin provides) into E60L (Toray provides).The result is as shown in table 1 below for the test gained.
Comparative example 5
To directly do weather resistance test (utilizing QUV weather resistance test machine, Q-panel company) less than the base material UX-150 (Teijin provides) that applies coating with concave-convex micro-structure and inorganic particulate.The result is as shown in table 1 below for the test gained.And survey its luminosity as shown in Figure 7.
Comparative example 6
Repeat the step of comparative example 5, just change base material UX-150 (Teijin provides) into E60L (Toray provides).The result is as shown in table 1 below for the test gained.
Method of testing:
The glossiness test: utilize Drlange Rrfo3 (Reflek TO Meter company sells) according to the ASTMD523 standard method, when light source is projeced into reflector plate with 60 ° of incident angles, measured glossiness (gloss) number percent.
The weather-proof accelerated test of QUV: utilize QUV weather resistance test machine (Q-panel company sells) along with different exposure time, its yellow index (Yellowing index, YI) Zhi variation.(testing main wavelength 313nm)
Luminosity: utilize automatic goniophotometer (GonioPhotometer) (GP-200, color company in the village),, record each angle reflection relative light intensity distribution curve with 60 ° of incident angles.
| 60 ° of % of glossiness | Rf% | ΔYI 300hr |
Embodiment 1 | 4.6 | 97.8 | 1.43 |
Embodiment 2 | 3.8 | 97.6 | 1.91 |
Comparative example 1 | 39.2 | 97.0 | 1.45 |
Comparative example 2 | 32.9 | 97.0 | 1.96 |
Comparative example 3 | 4.8 | 97.5 | 10.73 |
Comparative example 4 | 4.7 | 97.3 | 18.69 |
Comparative example 5 | 39.1 | 96.0 | 11.62 |
Comparative example 6 | 35.4 | 96.5 | 20.53 |
By the result of embodiment 1 and embodiment 2 as can be known, coating in the substrate surface coating, owing to contain organic filler with concave-convex micro-structure, thereby has a effect with light diffusion, simultaneously owing to contain the ultraviolet inorganics of absorption, and have preferred anti-yellow effect, can provide base material anti-UV character.
The comparative result of embodiment 1 and comparative example 1 and embodiment 2 and comparative example 2 as can be known, in the coating of substrate surface coating, if lack organic filler with concave-convex micro-structure, the effect of the light of not having so diffusion.
The comparative result of embodiment 1 and comparative example 3 and embodiment 2 and comparative example 4 as can be known, in the coating of substrate surface coating, if lack the inorganics with ultraviolet absorption ability, yellow easily takes place in base material so.
The comparative result of embodiment and comparative example as can be known, the coating in substrate surface coating contains the organic filler with concave-convex micro-structure, also contains simultaneously to absorb ultraviolet inorganics, its reflectivity is better, brightness is higher.
The luminosity figure result of comparing embodiment 1 and comparative example 5 has the coating of concave-convex micro-structure in the substrate surface coating as can be known, has the light diffusion effect.