TWI497167B - Direct-type backlight module and diffuser structure - Google Patents

Description

Direct type backlight module and light source diffusion structure thereof

The invention relates to a backlight module, in particular to a direct type backlight module and a light source diffusion structure thereof.

The liquid crystal panel emits light by entering the light incident surface of the light guide plate by the light processing component of the backlight module. The light processing component may be made of glass material or plastic material, and the light processing component is filled with phosphor powder as a wavelength conversion material. Accordingly, the light processing element converts a portion of the light source emitted by the light emitting element into a light source of another wavelength and mixes with the remaining light source emitted by the light emitting element to emit white light.

Among them, the phosphor powder filled in the light processing element can be classified into inorganic phosphor powder or organic phosphor powder. Moreover, there are currently light processing elements filled with quantum dot phosphor powder. However, the light conversion efficiency of the phosphor powder is not high, especially the inorganic phosphor powder having a long service life, and the light conversion efficiency is lower than that of the organic phosphor powder. In addition, the quantum dot phosphor powder is also susceptible to degradation by the short-wavelength source, and the greater the intensity of the light source per unit area of the quantum dot phosphor, the faster the brightness and saturation of the light decay.

Herein, the reduction of the light conversion efficiency of the quantum dot fluorescent powder beside the high-temperature light-emitting diode is unexpected, so that the brightness and saturation of the light are severely deteriorated after the optical processing element is used for a period of time. Moreover, the phosphor powder is liable to cause a qualitative change in the environment, resulting in a shortened service life of the light processing element or a color cast phenomenon.

Therefore, how to make the brightness and saturation of the quantum dot fluorescent powder in the light processing element is not easy to be degraded, and having good luminescent characteristics and a long service life is one of the most urgent problems to be solved.

In view of the above, the present invention provides a light source diffusion structure, comprising: a diffusion body, a plurality of sub-point fluorescent powders and a plurality of water blocking gas layers; wherein the plurality of sub-point fluorescent powders are dispersed in the diffusion body; the plurality of water blocking gas layers are located Diffusion of the surface of the body.

The invention also provides a direct type backlight module, comprising: a light source diffusion structure, a plurality of light emitting elements and at least one optical film; wherein the plurality of light emitting elements project light toward the light source diffusion structure, and the plurality of light emitting elements and the light source diffusion structure are mixed Optical space; the optical film is located on the light source diffusion structure.

In the embodiment of the present invention, the plurality of sub-point fluorescent powders are dispersed in the diffusion body of the diffusion plate or the diffusion sheet to effectively extend the service life thereof, and the quantum dot fluorescent spot material in the prior art is susceptible to short-wave source illumination and thermal decay. The problem is that the NTSC color gamut can be increased from 72% of the known technology to 100%.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art.

1 and 2 are embodiments of the light source diffusion structure of the present invention. Fig. 1 is a schematic cross-sectional view of a diffusing plate, and Fig. 2 is a schematic cross-sectional view of a diffusing sheet.

As shown in FIGS. 1 and 2, the light source diffusing structure 2 of the present invention comprises a diffusing body 21, a plurality of sub-point phosphors 23, and a plurality of water-blocking gas layers 25.

In some embodiments, as shown in FIG. 1, the light source diffusion structure 2 is a diffusion plate. here, The plurality of sub-point phosphors 23 are uniformly dispersed in the diffusing body 21, and a water-blocking gas layer 25 is respectively disposed on the surface of the diffusing body 21 to block the moisture from causing the luminous intensity of the quantum dot fluorescent powder 23 to decay.

In some embodiments, as shown in FIG. 2, the light source diffusion structure 2 is a diffusion sheet. Here, the diffusion body 21 can be mainly composed of the body layer 211 and the plurality of transparent layers 212. The plurality of transparent layers 212 are respectively disposed on the surface of the body layer 211, and the plurality of sub-point phosphors 23 are dispersed in the body layer 211, and The water-repellent gas layer 25 is respectively disposed on the surface of the light-transmitting layer 212 to block the moisture to prevent the light-emitting intensity of the quantum dot fluorescent powder 23 from deteriorating. In some embodiments, as shown in FIG. 3, a plurality of sub-point phosphors 23 may be dispersed in the plurality of light transmissive layers 212.

In the foregoing description, the light source diffusion structure 2 has a thickness of between about 0.5 mm and 3.0 mm, preferably between 1.0 mm and 2.0 mm.

As shown in FIG. 1, FIG. 2, and FIG. 3, the plurality of sub-point phosphors 23 are uniformly dispersed in the diffusion body 21, but the invention is not limited thereto, for example, as shown in FIG. 4, due to the quantum dots. The phosphor powder 23 is a nano quantum dot structure, and has the characteristics of being difficult to disperse and easily agglomerate. Therefore, the complex number of sub-point phosphors 23 can be prepared and dispersed in the solid diffusion particles 22, and then the quantum dot fluorescent powder 23 can be prepared. The diffusion particles 22 are uniformly disposed in the diffusion body 21. The size of the quantum dot fluorescent powder is between 1 nm and 10 nm, and the size of the diffusion particles 22 is between 1 μm and 10 μm, but the invention is not limited thereto.

In some embodiments, as shown in FIG. 4A, the complex number of sub-point phosphors 23 are uniformly dispersed in the solid diffusion particles 22. In some embodiments, as shown in FIG. 4B, the solid diffusion particles 22 are provided with a plurality of micropores 221, and the plurality of sub-point phosphors 23 are distributed on the surface of the pore channels or micropores 221 of the micropores 221 .

In the foregoing description, the material of the diffusion body 21 may be selected from the group consisting of polycarbonate (Polycarbonate), PMMA, MS, ABS, PET, PETG, PS, MBS, and COC, and the material of the diffusion particles 22 is phase. Different from the diffusion body 21, and may be selected from the group consisting of PMMA, MS, ABS, PS, PU, oxide containing SiO ₂ , Mg(OH) ₂ , CaCO ₃ , BaSO ₄ , Al ₂ O ₃ and TiO ₂ .

The diffusing particles 22 and the diffusing body 21 form a refractive index difference by the characteristics of the different materials, thereby forming a light diffusing effect. Generally, the refractive index values of the diffusing body 21 and the diffusing particles 22 differ by about 0.03 or more, preferably It can be greater than or equal to 0.1. For example, the diffusion body 21 is made of PS material and has a refractive index of about 1.59, and the diffusion particle 22 is made of PMMA, and its refractive index is about 1.49.

In the present embodiment, the percentage of the weight of the diffusion particles 22 to the whole (light source diffusion structure 2) is between 0.1% and 20%, preferably between 0.1% and 5%. The weight percentage is determined by the difference in refractive index between the diffusion particles 22 and the diffusion body 21. When the refractive index of the phase difference is smaller, the weight percentage of the diffusion particles 22 is larger as a whole.

In some embodiments, as shown in FIG. 5, the light source diffusion structure 2 is provided with a microstructure layer 26 on the diffusion body 21, and a microstructure layer 26 is preferably formed on the water blocking gas layer 25. Here, the microstructure layer 26 may be a continuous curve surrounded by a plurality of closed patterns, or a plurality of side-by-side light diffusion patterns, or a convex portion having an angular cross section, and the like, and the present invention is not limited thereto.

In some embodiments, the light source diffusion structure 2 is a flat plate diffusion structure, and the microstructure layer 26 is an irregular microstructure layer. In the structure in which the light source diffusion structure 2 has an irregular microstructure layer, the percentage of the weight of the diffusion particles 22 to the whole is between 0.1% and 20%, preferably the percentage of the whole is between 0.1% and 5 %between.

In some embodiments, the light source diffusion structure 2 is a microstructure diffusion structure, and the microstructure layer thereof 26 is a periodic microstructure layer (regular microstructure layer). In the structure in which the light source diffusion structure 2 has a periodic microstructure layer, the percentage of the weight of the diffusion particles 22 to the whole is between 0.1% and 4%, preferably the percentage of the whole is between 0.1% and 1%. between.

Fig. 6 is an embodiment of a direct type backlight module of the present invention. FIG. 6 is a schematic cross-sectional view of the direct type backlight module 1. The direct type backlight module 1 of the present invention comprises a light source diffusion structure 2, a plurality of light-emitting elements 4, and an optical film 6.

The light-emitting elements 4 can be light-emitting diodes (LEDs) arranged in a matrix arrangement on the bottom of the direct-type backlight module 1, and a reflective sheet (not shown) can be placed on the bottom of the direct-type backlight module 1. A light source diffusing structure 2 is disposed above the light emitting element 4 to project light toward the light source diffusing structure 2 by the light emitting element 4, and a plurality of light emitting elements 4 and the light source diffusing structure 2 are spaced apart to form an air layer. The air layer acts as a light mixing space. In addition, the light source diffusion structure 2 may be provided with an optical film 6, such as a light shielding sheet, a cymbal sheet or the like. Here, the light source diffusion structure 2 is as described above, and will not be described here.

In some embodiments, the light source diffusion structure 2 (as shown in FIG. 1) and the plurality of diffusion sheets are sequentially disposed in a direction away from the light-emitting element 4 in a direction away from the light-emitting element 4, or sequentially. A light source diffusion structure 2 of a plurality of diffusion plates and a diffusion sheet structure is provided (as shown in FIG. 2). However, the foregoing arrangement is only an example, and the present invention is not limited thereto.

In some embodiments, the light-emitting element 4 is an LED of a blue-polar diode chip, and the light projected by the light-emitting element is blue light. When the light is projected onto the light source diffusion structure 2, a portion of the blue light is converted by the plurality of sub-point fluorescent powders 23, respectively. The red and green light forms a high color rendering with a half-width intensity of the peak of the light-emitting spectrum of less than or equal to 100 nm. Therefore, the visual effect allows the user to see a purer and more beautiful picture of the light.

In some embodiments, the light-emitting element 4 is an LED composed of a blue diode chip plus a green diode chip or a blue diode chip plus a green light phosphor, or may be a blue diode chip. The LED composed of non-quantum dot green fluorescent powder, the projected light is a mixture of blue light and green light, and the plurality of sub-point fluorescent powder 23 can convert part of the blue light and part of the green light into red light, so that the direct type backlight The module 1 combines high color rendering, long light source intensity and high efficiency light source characteristics.

In some embodiments, the light-emitting element 4 is a blue LED chip plus a red LED chip or a blue chip plus a red phosphor powder LED, and the projected light is blue light and red light, and the plurality of light The spot fluorescent powder 23 can convert part of the blue light into green light (because the quantum dot fluorescent powder 23 only converts the short-wavelength light, the quantum dot fluorescent powder 23 only converts part of the blue light into green light), so that the direct-lit backlight module 1 At the same time, it takes into consideration the high color rendering picture, the long light source intensity life and the high efficiency light source characteristics.

In the embodiment of the present invention, the plurality of sub-point fluorescent powders are dispersed in the diffusion body of the diffusion plate or the diffusion sheet to effectively extend the service life thereof, and the quantum dot fluorescent spot material in the prior art is susceptible to being irradiated by the short-wave light source to be degraded. The problem, combined with high color rendering, long light source intensity life and high efficiency light source characteristics, has increased the NTSC color gamut from 72% of the conventional technology to 100%.

Although the technical content of the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention, and any modifications and refinements made by those skilled in the art without departing from the spirit of the present invention are encompassed by the present invention. The scope of protection of the present invention is therefore defined by the scope of the appended claims.

1‧‧‧Direct type backlight module

2‧‧‧Light source diffusion structure

21‧‧‧Diffusion ontology

211‧‧‧ body layer

212‧‧‧Transparent layer

22‧‧‧Diffusion particles

221‧‧‧Micropores

23‧‧‧Quantum point phosphor powder

25‧‧‧Water barrier layer

26‧‧‧Microstructural layer

4‧‧‧Lighting elements

6‧‧‧Optical diaphragm

Figure 1 is a schematic cross-sectional view of a diffuser plate of the present invention.

Fig. 2 is a schematic cross-sectional view (I) of the diffusion sheet of the present invention.

Fig. 3 is a schematic cross-sectional view (2) of the diffusion sheet of the present invention.

Figure 4 is a schematic cross-sectional view showing a light source diffusion structure having diffusing particles according to the present invention.

Fig. 4A is a schematic cross-sectional view (I) of the diffusion particles of the present invention.

Fig. 4B is a schematic cross-sectional view (2) of the diffusion particles of the present invention.

Figure 5 is a schematic cross-sectional view showing a light source diffusion structure having a microstructured layer of the present invention.

Figure 6 is a cross-sectional view showing the direct type backlight module of the present invention.

2‧‧‧Light source diffusion structure

21‧‧‧Diffusion ontology

22‧‧‧Diffusion particles

25‧‧‧Water barrier layer

Claims (9)

A light source diffusion structure comprising: a diffusion body; a plurality of sub-point fluorescent powders uniformly dispersed in the diffusion body, wherein the quantum dot fluorescent powders are dispersed in the pore channels of the plurality of micropores of the plurality of diffusion particles, The diffusion particles are dispersed in the diffusion body; and the plurality of water blocking gas layers are located on the surface of the diffusion body. The light source diffusion structure of claim 1, wherein the diffusion body comprises a body layer and a plurality of light transmissive layers, the light transmissive layers are located on a surface of the body layer, and the quantum dot phosphor powder is dispersed in the light transmission In the layer. The light source diffusion structure of claim 1, wherein the quantum dot phosphor powder has a size between 1 nm and 10 nm, and the diffusion particles have a size between 1 μm and 10 μm. The light source diffusion structure of claim 1, wherein the diffusion body and the diffusion particles have a refractive index value that is not less than 0.03. The light source diffusion structure of claim 1, wherein the weight of the diffusion particles is between 0.1% and 20% by weight. A direct type backlight module comprising: a light source diffusion structure according to any one of claims 1 to 5; a plurality of light emitting elements projecting light toward the light source diffusion structure, wherein the light emitting elements and the light source diffusion structure have a mixture An optical space; and at least one optical film on the light source diffusion structure. The direct type backlight module of claim 6, wherein the light emitted by the light emitting elements is blue Light, the quantum dot phosphors respectively convert part of the blue light into red light and green light, and the half-width intensity of the peak of the light-emitting spectrum is less than or equal to 100 nm. The direct type backlight module of claim 6, wherein the light emitted by the light emitting elements is composed of a blue diode chip and a green diode chip, or a blue diode chip and a non-quantum dot green light. The composition of the phosphor powder, which converts part of the blue light and part of the green light into red light. The direct-lit backlight module of claim 6, wherein the light emitted by the light-emitting elements is composed of a blue diode chip and a red diode chip, or a blue diode chip and a non-quantum dot red light. The composition of the phosphor powder, which converts part of the blue light into green light.