CN1629693A - Diffuser structure for increased penetration - Google Patents

Abstract

The invention provides a diffusion plate structure, wherein an anti-reflection layer with low reflectivity is formed on the lower surface of the diffusion plate structure, the anti-reflection layer is thermosetting resin and comprises a plurality of nano-sized particles, the nano-sized particles use ethanol as a solvent and are randomly mixed in the thermosetting resin, and the anti-reflection layer has the characteristic of low reflectivity, so that when incident light passes through the thin film layer, the transmittance of the thin film layer can be improved. Meanwhile, since the anti-reflection layer has a plurality of nano-particles, the incident light will be diffused when passing through the anti-reflection layer, and a surface light source with uniform display and high brightness is provided.

Description

Diffuser structure for increased penetration

technical field

The invention relates to a structure of a diffusion plate, in particular to a structure of a diffusion plate which can increase the transmittance in a liquid crystal display device.

Background technique

Liquid Crystal Display (LCD) is a non-self-illuminating display device, which needs a backlight source to achieve the display function. Under the fixed backlight system, the light transmittance of the diffusion film will directly affect the utilization effect of the light source, and then affect the image quality of the liquid crystal display. It is a very important component in the module of the liquid crystal display. High-quality, large-size liquid crystal displays must be supported by high-performance backlight technology. Therefore, the high performance of backlight technology, such as high brightness, low cost, low power consumption, and light weight, etc. Plays a very important role in the performance of the overall performance.

The backlight module in a liquid crystal display generally includes a light source (that is, a cold cathode tube), a reflector, a light guide plate, a diffusion plate, etc., among which, the function of the diffusion plate can effectively disperse the incident light and provide a uniform light for the liquid crystal display. surface light source. A traditional diffusion plate includes a transparent substrate and a diffusing layer, which is formed on the surface of the transparent substrate, and the diffusion layer contains spherical material particles of scatters, and the diffusion of the diffusion plate The effect is mainly due to the difference in refractive index between the binder in the diffusion layer and the filled scatterers. Scatterers are scattered between the diffusion layers. When the light passes through the diffusion layer, it will continuously pass through the two media with different refractive indices. At this time, the light will refract, reflect and scatter at the same time, that is, the effect of optical diffusion. .

With the rapid development of flat-panel displays, high-quality display quality plays an indispensable role. Among them, the brightness performance of flat-panel displays is an important part, and anti-reflection film is one of the important applications in improving the brightness performance. The function of the anti-reflection film is to reduce the reflection and increase the light penetration of the display element. The principle is mainly to use the characteristics of penetration and reflection when the incident wavelength passes through the anti-reflection coating, while part of the incident wavelength passes through, and part of the incident wavelength passes through. Reflection, by controlling the product of the refractive index and thickness of the reflective coating to be an odd multiple of the incident wavelength 1/4λ, interference occurs and the reflection effect is obtained.

For LCD panels, every 1% increase in reflectivity means a loss of 1% of transmittance, that is, a loss of 1% of brightness. Therefore, LCD panels must increase their transmittance as much as possible while reducing their reflectivity.

The traditional diffuser plate structure is briefly described as follows with Figure 1. Referring to Fig. 1, a transparent substrate 101 is provided, the material of this transparent substrate 101 can be acrylic (acrylic) resin sheet, for example the polymethyl methacrylate (polymethyl methacrylate) of homopolymer (homopolymer), on this transparent substrate 101 A diffusing layer is deposited, and the diffusing layer includes a polymerizable binder (binder) 103 and a plurality of spherical diffusers 105 . The polymeric adhesive 103 is formed using a high molecular polymer containing polyalkyl methacrylate as the main functional group, such as polymethyl methacrylate or polypropyl methacrylate ( polypropylmethacrylate) and so on. The scatterers 105 can include any substance with a refractive index, and its refractive index is different from that of the transparent substrate 101, the adhesive 103 and the acrylic resin film 107, and the material of the scatterers 105 can be silicon oxide, magnesium oxide (magnesium oxide), titanium oxide (titanium oxide), etc., and the size of its particles can be between 1 and 100 microns. A polyethylene resin film 107 is formed on the diffusion layer, which has the same composition as the transparent substrate 101 .

When the incident light passes through the diffusion layer comprising the scatterers 105 and the adhesive 103, since the refractive indices of the scatterers 105 and the adhesive 103 are different, the incident light will be refracted, reflected and scattered when passing through, and also That is, the incident light achieves the effect of being diffused, but the penetration rate of light in this conventional diffuser plate is not high, and its penetration rate can only reach 85%. Therefore, the utilization rate of light is not high, which further affects a display. The overall brightness performance of components such as liquid crystal displays.

To sum up, since the traditional diffuser structure cannot increase the transmittance of incident light, it is urgent to provide an improved diffuser structure to increase the transmittance of light and increase the brightness of the display.

Contents of the invention

One object of the present invention is to provide a diffusion plate structure, which includes forming an anti-reflection layer with low reflectivity under the diffusion plate. This anti-reflection layer can increase the transmittance of incident light, and further increase the brightness performance of the display. .

Another object of the present invention is to provide a diffusion plate structure, which includes providing a thermosetting resin with nano-sized particles, which can utilize the characteristics of different refractive indices of the nanoparticles and the thermosetting resin to provide a uniform surface light source for the display, And improve the performance of the backlight module.

In accordance with the objects stated above, the present invention provides an improved diffuser plate. First, provide a transparent substrate, such as a plastic resin substrate, its material can be polycarbonate, polystyrene, polyene, polyether, polyester, polyamide, polyphenylene sulfide, polyether ester, polyvinyl chloride Or polymethacrylic resin and so on. A diffusion layer is formed on the upper surface of the transparent substrate, and the diffusion layer includes a plurality of spherical particles and a main material, wherein the material of the plurality of spherical particles is an organic polymer, such as polymethyl methacrylate, an inorganic material, Such as titanium dioxide (TiO ₂ ), silicon dioxide (SiO ₂ ) or glass beads, etc., and the main material is also an organic polymer, such as urethane resin, vinyl acetate resin, vinyl chloride resin, styrene resin or Polyethylene resin etc., meanwhile, this diffusion layer can be a wedge shape or an irregular shape. An anti-reflection layer with low reflectivity is formed under the transparent substrate. The anti-reflection layer includes a thermosetting resin and a plurality of nanoscale particles. The thermosetting resin and the plurality of nanoscale particles are dispersed using ethanol as a solvent. , and the two can be arbitrarily mixed in a single process, such as a wet process or a dry process. Finally, the anti-reflection layer with low reflectivity is coated or evaporated on the lower surface of the transparent substrate.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a diffuser plate structure in the prior art;

Fig. 2 is a schematic cross-sectional view of a preferred embodiment of the diffusion plate structure of the present invention that can increase the penetration rate;

FIG. 3 is a cross-sectional schematic diagram of a diffusion plate structure capable of increasing transmittance and a backlight module according to the present invention.

Explanation of symbols in the figure:

101 transparent substrate

103 adhesive

105 scatterers

107 Acrylic resin film

201 transparent substrate

203 main material layer

205 spherical particles

207 thermosetting resin

209 nanoscale particles

211 Light guide plate

213 Diffusion point

215 reflector

217 incident light

219 light source

Detailed ways

The following is a detailed description of the present invention, and the description of the process and structure in the following description does not include the complete process of manufacture. The prior art used in the present invention is only cited here as an emphatic reference to help explain the present invention.

The content of the present invention can be disclosed through the following description of a preferred embodiment and its related accompanying drawings 2 to 3 . Referring to Fig. 2, at first, provide a transparent substrate 201 with high transparency and high mechanical strength, such as a plastic resin substrate, the thickness range of this transparent substrate 201 is between 25-150 microns (micrometer, μ m), in addition, this plastic The material of the transparent substrate 201 of the resin film can be polycarbonate (polycarbonate), polystyrene (polystyrene), polyester (polyester), polyene (polyolefin), polyether (polyether), polystyrene (polystyrene), poly Polyamide, polyphenylenesulfide, polyether-ester, polyester or polymethacrylate, etc.

Next, a diffusion layer is formed on the transparent substrate 201, the diffusion layer includes a plurality of spherical particles 205 doped in a host material layer 203, the material of the plurality of spherical particles 205 is an organic polymer material Or an inorganic material, such as polymethyl methacrylate (polymethyl methacrylate, PMMA), titanium dioxide (TiO ₂ ), silicon dioxide (SiO ₂ ) or glass beads, etc. The material of the main material layer 203 is also an organic polymer materials, such as urethane resin, vinyl acetate resin, vinyl chloride resin, styrene resin or polyethylene resin, etc. On the other hand, the shape of the diffusion layer formed by the plurality of spherical particles 205 and the main material layer 203 can be wedge-shaped or irregular, wherein the main material layer 203 is a fluid. In addition, the size of each spherical particle 205 is between 1 to tens of micron meters. It should be noted that the refractive index of each spherical particle 205 is different from the refractive index of the main material layer 203, so when the incident light passes through the interface between the main material layer 203 and the plurality of spherical particles 205, Only then can the effect of light being diffused be achieved.

In the manufacturing method of the above-mentioned diffusion plate, the spherical particles 205 are mixed into the main material layer 203, and the diffusion layer comprising the main material layer 203 and a plurality of spherical particles 203 is coated on the surface of the transparent substrate 201 by coating. After that, a curing process is performed to evaporate the organic solvent in the diffusion layer. In this diffusion layer, the purpose of mixing a plurality of spherical particles 205 into the main material layer 203 is to obtain a high density of a plurality of spherical particles 205, and through this high density of a plurality of spherical particles 205, when the incident light passes through the diffusion layer will be evenly diffused, but the weight of the spherical particles 205 should not exceed 300% of the weight of the main material layer 203 , otherwise the incident light will not only have a proper penetration rate, but also affect the adhesion of the resin. On the other hand, the weight of the spherical particles 205 should not be less than 10% of the weight of the main material layer 203 , otherwise, the effect of diffusing the incident light will be affected. Therefore, the density of spherical particles 205 must be properly controlled.

Since the diffuser plate formed by the spherical particles 205 and the main material 203 can make the incident light penetrate, but its achievable transmittance is limited, for example, 85% of the light transmittance, therefore, the present invention is based on the transparent substrate 201 An anti-reflection layer (Anti-Refection layer) with low reflectivity (lowreflectivity) is formed on the lower surface, and the anti-reflection layer includes a plurality of nano-scale particles 209 and a thermosetting resin (thermosetting resin) 207. Nanoscale particles 209 are randomly mixed in the thermosetting resin 207, and the two are mixed in an ethanol solvent, and the thickness of the anti-reflection layer is in the range of 1-30 microns, and the size range of the plurality of nanoparticles is In 0.001 micron to 0.1 micron. When the incident light passes through the anti-reflection layer formed by the plurality of nanoparticles 209 and the thermosetting resin 207 , the incident light will have the characteristics of transmission and reflection at the same time. Since the present invention forms an antireflection layer comprising a plurality of nanoparticles 209 and a thermosetting resin 207, and the antireflection layer has the characteristics of low reflectivity, therefore, the reflectivity of incident light can be reduced, and the reflectivity of incident light can be improved. Transmittance, such as 5% light transmittance. In addition, the anti-reflection layer has a plurality of nanoparticles 209. Therefore, when the incident light passes through the film layer, it can increase the effect of the incident light being diffused, thereby providing a display, such as a liquid crystal display, giving a uniform and high brightness. High surface light source.

Furthermore, the anti-reflection layer comprising a plurality of nanoparticles 209 and the thermosetting resin 207 utilizes a process, such as a wet process, to form the anti-reflection layer on the lower surface of the transparent substrate 201, wherein the wet process Utilize a coating method, or an ultra-thin coating method, such as the method of micro-gravure coating (micro-gravure coating), the method of substrate tension extrusion (web tension coating), the antireflection layer is coated cloth on the lower surface of the transparent substrate 201, and then perform a curing process to remove the ethanol solvent in the anti-reflection layer. In addition, during the dry process, after mixing the thermosetting resin 207 and the plurality of nanoparticles 209 with an ethanol solvent, an evaporation method, such as a vacuum evaporation method, is used to form the anti-reflection layer with low reflectivity. Evaporated on the lower surface of the transparent substrate 201, because the evaporation method can precisely control the thickness of the anti-reflection layer, therefore, in all visible light ranges (400-700nm), its reflectivity can be controlled below 0.5%. Finally, the structure of the diffuser plate of the present invention is completed.

The anti-reflection layer with low reflectivity of the present invention can improve the transmittance of incident light by about 5% after actual testing. The diffusion plate structure with high transmittance, and adding this structure to the application of a backlight module, can compensate the light intensity lost when the incident light passes through the backlight module. As shown in FIG. 3 , a backlight module is provided, and the backlight module includes a light source 219 , and the light source 219 can provide a parallel incident light 217 . In addition, the backlight module also provides a light guide plate 211 on the lower surface of the anti-reflection layer with low reflectivity. The material of the light guide plate 211 can be acrylic resin. The dots 213 are on the surface of the bottom surface of the light guide plate 211 , wherein the material of the diffusion dots 213 may be titanium dioxide (titanium dioxide, TiO ₂ ). In addition, the backlight module further provides a reflection plate 215 on the lower surface of the light guide plate 211 to increase the use efficiency of the incident light 217 . When the diffuser structure of the present invention is added to the backlight module, the diffuser structure has high transmittance characteristics, so it can be provided to a display, such as a liquid crystal display, to provide a high-performance backlight technology.

From the above description of the preferred embodiments of the present invention, it can be understood that one of the advantages of the present invention is to provide a diffuser plate structure, which forms an anti-reflection layer with low reflectivity on the lower surface of the diffuser plate structure, The anti-reflection layer is a thermosetting resin and includes a plurality of nano-scale particles, and the plurality of nano-scale particles are randomly mixed in the thermosetting resin with ethanol as a solvent, because the anti-reflection layer has a low reflectivity properties, so when the incident light passes through the film layer, its transmittance can be improved. What's more, because the anti-reflection layer has a plurality of nanoparticles, the light of the incident light passing through the anti-reflection layer will have the effect of being diffused. Therefore, a surface light source with uniformity and high brightness can be provided for the display.

The above descriptions are only preferred specific embodiments of the present invention, and are not intended to limit the patent application rights of the present invention. At the same time, the above descriptions should be clear and implementable for those who are familiar with the technical field, so others do not depart from the present invention. Equivalent changes or modifications accomplished under the disclosed spirit shall be included in the scope of the patent application.

Claims (10)

1. diffusion board structure that can improve penetrance comprises:

One transparency carrier;

One diffusion layer is positioned at surface on this transparency carrier; And

The anti-reflecting layer of one antiradar reflectivity is on the surface below of this transparency carrier.

2. the diffusion board structure that improves penetrance as claimed in claim 1, wherein above-mentioned diffusion layer comprises the particle of a plurality of ball-types.

3. the diffusion board structure that improves penetrance as claimed in claim 1, the anti-reflecting layer of wherein above-mentioned antiradar reflectivity comprise a plurality of how meter level particles.

4. the diffusion board structure that improves penetrance as claimed in claim 1, the material of the anti-reflecting layer of wherein above-mentioned antiradar reflectivity are a thermoset resin.

5. the diffusion board structure that improves penetrance as claimed in claim 4, the anti-reflecting layer of wherein above-mentioned antiradar reflectivity comprise a plurality of how meter level particles.

6. the diffusion board structure that improves penetrance as claimed in claim 3, the anti-reflecting layer of wherein above-mentioned antiradar reflectivity more comprises an alcohol solvent.

7. can improve the diffusion board structure of penetrance in the backlight module, comprise:

One resinous plastic substrate;

One resin is positioned on this resinous plastic substrate on the surface, and wherein this resin comprises the particle of a plurality of ball-types; And

One thermoset resin is on the surface below of this resinous plastic substrate, and wherein this thermoset resin comprises a plurality of nanoparticles.

8. can improve the diffusion board structure of penetrance in the backlight module as claimed in claim 7, the resin of the wherein above-mentioned particle that comprises a plurality of ball-types, its material can be selected from following person: vinyl acetate resin and vestolit and styrene resin.

9. can improve the diffusion board structure of penetrance in the backlight module as claimed in claim 7, the wherein above-mentioned thermoset resin that comprises a plurality of nanoparticles comprises a thermoset resin with antiradar reflectivity.

10. can improve the diffusion board structure of penetrance in the backlight module as claimed in claim 9, the thermoset resin of wherein above-mentioned antiradar reflectivity more comprises an alcohol solvent.