TW201708907A - Light source module - Google Patents

Abstract

A light source module including a light source, a diffusion film, a wavelength conversion optical film and a porous optical film is provided. The diffusion film is located above the light source, and the wavelength conversion optical film is located above the diffusion film. The porous optical film is located in between the light source and the diffusion film, wherein the porous optical film has a central region and a peripheral region surrounding the central region. The central region is arranged corresponding to the light source, wherein the central region has a plurality of first pores. The periphery region has a plurality of second pores, and the pore size of the second pores is greater than the pore size of the first pores. The area of the first pores accounts for an area of 0.5~25% of the central region.

Description

Light source module

The present invention relates to a light source module, and more particularly to a light source module having a porous optical film.

The liquid crystal display device usually includes a liquid crystal display panel and a light source module, wherein the light source module is mainly used to provide a surface light source required for the liquid crystal display panel to display. In general, the light source module can be divided into a direct type and an edge-lit type according to the position set by the light source. The light source of the direct light source module is disposed directly under the light source module, and is generally used for a larger size liquid crystal display, and the light source of the side light type light source module is disposed on a side of the light source module, which is generally used for smaller Size LCD display.

In order to prevent uneven brightness of the liquid crystal display, an optical film is generally used to uniformize the brightness of the entire screen, and to maintain the brightness of the entire screen without damaging the brightness of the light source. As far as the prior art is concerned, the optical film such as a diffuser (Diffuser) is mainly used for the purpose of uniformity and concentration of light. However, in order to achieve the purpose of light homogenization, in the conventional method, there is a problem that a chromatic aberration occurs between the light source and the light source due to the difference in reflectance. Therefore, how to maintain the brightness uniformity of the picture and reduce the problem of chromatic aberration is the subject of current research.

The present invention provides a light source module that can be used to uniformize the brightness of a liquid crystal display while reducing the problem of chromatic aberration.

The light source module of the present invention includes a light source, a diffusion plate, a wavelength conversion optical film, and a porous optical film. The diffuser plate is above the light source and the wavelength converting optical film is above the diffuser plate. The porous optical film is located between the light source and the diffuser plate, wherein the porous optical film has a central region and a peripheral region located around the central region. The central area is disposed corresponding to the light source, wherein the central area has a plurality of first holes. The peripheral region has a plurality of second holes, and the second holes have a larger diameter than the first holes. The area of the first hole accounts for 0.5 to 25% of the area of the central area.

Based on the above, the light source module of the present invention includes a porous optical film, and the porous optical film has a plurality of first holes disposed in the central region, and the second holes are disposed in the peripheral region, so that the brightness of the screen can be uniform And at the same time reduce the problem of chromatic aberration.

The above described features and advantages of the invention will be apparent from the following description.

1A to 1C are schematic cross-sectional views showing a light source module according to an embodiment of the present invention. 2 is a top plan view of a porous optical film according to an embodiment of the present invention. Please refer to FIG. 1A to FIG. 1C and FIG. 2 at the same time. In the embodiment, the light source module 100 includes a light source LS, a diffusion plate 110, a wavelength conversion optical film 120, and a porous optical film 130. In addition, the light source module 100 also includes a metal back plate, a plastic frame, and a circuit control system (not shown), wherein each of the light sources LS is driven by the circuit control system. In this embodiment, only a single light source LS is described. However, it is worth noting that the light source module 100 substantially includes a light source matrix formed by a plurality of light sources LS, and is arranged on the substrate Sub of the light source module 100. The configuration of the light source LS in conjunction with the wavelength converting optical film 120 can be used to mix light into white light. In addition, the color of the light source LS is not particularly limited and may be more than one color.

Referring to FIG. 1A to FIG. 1C , the diffusion plate 110 is located above the light source LS and can be used to enhance the display brightness of the light source module 100 . The wavelength conversion optical film 120 is located above the diffusion plate 110, wherein the material of the wavelength conversion optical film 120 includes quantum dots as a base material or a phosphor material. The quantum dots of the wavelength conversion optical film 120 are, for example, cadmium selenide/zinc sulfide (CdSe/ZnS) or a material having similar characteristics. In the wavelength conversion optical film 120, the host material as a quantum dot material may be, for example, polycarbonate, polymethylmethacrylate, or acrylonitrile-butadiene-styrene. ), polyethylene terephthalate, epoxy resin or glass. Further, the wavelength conversion optical film 120 can be combined with diffusion particles such as titanium oxide (TiO ₂ ) or aluminum oxide (Al ₂ O ₃ ) to increase diffusibility.

In this embodiment, a layer of water blocking material (not shown) may be further coated on the wavelength conversion optical film 120. The layer of water blocking material can be used to reduce the degradation of the luminous intensity characteristics caused by moisture to the quantum dots or phosphorescent materials. Further, the diffusion plate 110 is disposed between the wavelength conversion optical film 120 and the porous optical film 130. Although the embodiment of FIGS. 1A to 1C only shows that the diffusion plate 110 of a single layer is disposed between the wavelength conversion optical film 120 and the porous optical film 130, the present invention is not limited thereto. For example, in another embodiment, a plurality of diffusion plates 110 may be disposed between the wavelength conversion optical film 120 and the porous optical film 130. Moreover, in another embodiment, an optical film such as a brightness enhancement film, a dual brightness enhancement film, or a microlens sheet may be used instead of the diffusion plate 110, or a combination thereof may be used. The film layer is used.

Next, referring to FIG. 1A to FIG. 1C and FIG. 2 simultaneously, the porous optical film 130 is located between the light source LS and the diffusion plate 110, and the porous optical film 130 is, for example, a reflective material including metal. The porous optical film 130 has a central region CR and a peripheral region PR located around the central region CR. In particular, the central region CR is disposed corresponding to the light source LS, wherein the central region CR has at least one first hole FH and the peripheral region PR has a plurality of second holes SH. Although the embodiment of FIG. 1A only shows four first holes FH and four second holes SH, it is worth noting that the first hole FH of FIG. 1A is substantially covered with the central area CR and the second hole SH It is covered with the surrounding area PR. In the present embodiment, the aperture a ₀ of the second hole SH is larger than the aperture a of the first hole FH, wherein the area of the first hole FH is 0.5 to 25% of the area of the central region CR. Preferably, the area of the first hole FH is 0.5 to 15% of the area of the central area CR.

In the present embodiment as shown in FIG. 1A, the center line of the light source LS extends, for example, through the porous optical film 130, but the first hole FH is not distributed where the center line of the light source LS passes. As shown in FIG. 1B and FIG. 1C, the porous optical film 130 illustrated in FIG. 1B also has a plurality of first holes FH, and the center line of the light source LS passes through one of the first holes FH of the porous optical film 130. In other words, the position at which the center of the light source LS is projected to the position of the porous optical film 130 (directly above) has the first hole FH. The porous optical film 130 illustrated in FIG. 1C has only one first hole FH, and the center line of the light source LS passes through the first hole FH. In particular, the opening area of the first hole FH is not more than 0.25 mm ² . Since the central region CR is provided with the first hole FH, it is possible to improve the phenomenon that the light source penetration energy is insufficient and the yellowish light is dark due to the excessively high reflection region directly above the light source LS. That is to say, the first hole FH can change the transmittance of the central region CR, so that the central region CR has both the characteristics of penetrating and reflecting light.

As described above, the first hole FH is disposed such that the aperture ratio of the porous optical film 130 produces one or more turns. In particular, the aperture ratio change transition of the porous optical film 130 is within a region 20 mm directly above each light source LS. In more detail, the opening ratio change transition of the porous optical film 130 may be one or more, so that the transmittance of the porous optical film 130 is gently lowered from the peripheral region PR toward the central region CR. In other words, the peripheral region PR has a higher transmittance, and the closer to the central region CR, the transmittance gradually decreases and tends to be flat.

Further, a vertical distance between the porous optical film 130 and the light source LS is H1, a vertical distance between the porous optical film 130 and the diffusion plate 110 is H2, and H2/H1 = 0.5 to 1.5. Further, in the porous optical film 130, a horizontal distance X ₀ from a center point of the light source LS to the outermost side of the central region CR of the porous optical film 130 is satisfied: X ₀ > (H1 × a ₀ ) / t. As described above, H1 represents a vertical distance between the porous optical film 130 and the light source LS, a ₀ represents the aperture of the second hole SH which is located to the outermost side of the central region CR, and t represents the porous optical film 130. thickness of. In other words, the area of the central region CR is centered on the light source LS and has an area of 2X ₀ in diameter.

In more detail, the aperture a of any of the first holes FH needs to satisfy: a ≧ (X*t) / H1. As stated above, X represents a horizontal distance from a center point of the light source LS to any of the first holes FH in the porous optical film 130, and H1 represents a vertical between the porous optical film 130 and the light source LS. The distance t represents the thickness of the porous optical film 130. In addition, as shown in FIG. 2, the aperture a ₀ of the second hole SH becomes larger as it goes away from the light source LS. In the porous optical film 130, the ratio of the area of the second hole SH to the area of the peripheral region PR is the opening ratio An. In particular, the opening ratio An needs to satisfy: An = bX _n ² + c, where X _n is the same as defined above for X ₀ , and b and c are coefficients. Regarding the peripheral region PR, the opening ratio An can be defined by referring to the patent document US 8,272,772. In addition, in the present embodiment, the shape of the first hole FH may be a tapered shape, a cylindrical shape, a trapezoidal shape or the like, but is not limited thereto.

Based on the above, the light source module 100 shown in FIGS. 1A to 1C includes a porous optical film 130, and the porous optical film 130 has a plurality of first holes FH disposed in the central region CR, and the second holes SH are disposed in the periphery. Regional PR. Further, the hole arrangement of the porous optical film 130 is required to satisfy the above conditions. Therefore, the light source module 100 can be used to uniformize the brightness of the screen while reducing the problem of chromatic aberration.

3A is a cross-sectional view of a light source module according to another embodiment of the present invention. Next, the light source module 300A of FIG. 3A will be described. The light source module 300A of FIG. 3A is similar to the light source module 100 of FIG. 1A, and therefore the same components are denoted by the same reference numerals and will not be described again. The embodiment of FIG. 3A differs from the embodiment of FIG. 1A in that the light source module 300A of FIG. 3A further includes a coating layer 140 disposed in a central region CR of the porous optical film 130. Coating layer 140 can include a wavelength converting material, a diffusing material, or a combination thereof. In detail, the material of the coating layer 140 may be selected from the materials of the diffusion plate 110 and the wavelength conversion optical film 120 described above, and combinations thereof. In addition, the surface of the coating layer 140 has a ruthenium pattern, a microlens pattern, or a roughened pattern. In the embodiment of FIG. 3A, the porous optical film 130 has a first surface facing the diffusion plate 110 and a second surface facing the light source LS, wherein the coating layer 140 is located on the first surface. on.

Based on the above, the light source module 300A shown in FIG. 3A includes the porous optical film 130, and the porous optical film 130 has a plurality of first holes FH disposed in the central region CR, and the second holes SH are disposed in the peripheral region PR. Further, the hole arrangement of the porous optical film 130 also needs to satisfy the above conditions. Therefore, the light source module 300A can be used to uniformize the brightness of the screen while reducing the problem of chromatic aberration.

3B is a cross-sectional view of a light source module according to another embodiment of the present invention. Next, the light source module 300B of FIG. 3B will be described. The light source module 300B of FIG. 3B is similar to the light source module 300A of FIG. 3A, and therefore the same components are denoted by the same reference numerals and will not be described again. The difference between the embodiment of FIG. 3B and the embodiment of FIG. 3A is that the coating layer 140 of the light source module 300B of FIG. 3B is located on the first surface of the porous optical film 130, and the coating layer 140 is filled in the first hole. Within FH.

Based on the above, the light source module 300B shown in FIG. 3B includes the porous optical film 130, and the porous optical film 130 has a plurality of first holes FH disposed in the central region CR, and the second holes SH are disposed in the peripheral region PR. Further, the hole arrangement of the porous optical film 130 also needs to satisfy the above conditions. Therefore, the light source module 300B can be used to uniformize the brightness of the screen while reducing the problem of chromatic aberration.

4A is a cross-sectional view of a light source module according to another embodiment of the present invention. Next, the light source module 400A of FIG. 4A will be described. The light source module 400A of FIG. 4A is similar to the light source module 300A of FIG. 3A, and therefore the same components are denoted by the same reference numerals and will not be described again. The embodiment of FIG. 4A differs from the embodiment of FIG. 3A in that the coating layer 140 of the light source module 400A of FIG. 4A is located on the second surface of the porous optical film 130. That is, the coating layer 140 is on the second surface of the porous optical film 130 facing the light source LS.

Based on the above, the light source module 400A shown in FIG. 4A includes the porous optical film 130, and the porous optical film 130 has a plurality of first holes FH disposed in the central region CR, and the second holes SH are disposed in the peripheral region PR. Further, the hole arrangement of the porous optical film 130 also needs to satisfy the above conditions. Therefore, the light source module 400A can be used to uniformize the brightness of the screen while reducing the problem of chromatic aberration.

4B is a cross-sectional view of a light source module according to another embodiment of the present invention. Next, the light source module 400B of FIG. 4B will be described. The light source module 400B of FIG. 4B is similar to the light source module 400A of FIG. 4A, and therefore the same components are denoted by the same reference numerals and will not be described again. The difference between the embodiment of FIG. 4B and the embodiment of FIG. 4A is that the coating layer 140 of the light source module 400B of FIG. 4B is located on the second surface of the porous optical film 130, and the coating layer 140 is filled in the first hole. Within FH.

Based on the above, the light source module 400B shown in FIG. 4B includes the porous optical film 130, and the porous optical film 130 has a plurality of first holes FH disposed in the central region CR, and the second holes SH are disposed in the peripheral region PR. Further, the hole arrangement of the porous optical film 130 also needs to satisfy the above conditions. Therefore, the light source module 400A can be used to uniformize the brightness of the screen while reducing the problem of chromatic aberration.

FIG. 5 is a cross-sectional view of a light source module according to another embodiment of the present invention. Next, the light source module 500 of FIG. 5 will be described. The light source module 500 of FIG. 5 is similar to the light source module 400B of FIG. 4B, and therefore the same components are denoted by the same reference numerals and will not be described again. The embodiment of FIG. 5 differs from the embodiment of FIG. 4B in that the coating layer 140 of the light source module 500 of FIG. 5 is filled into the first hole FH but does not cover the first surface or the second surface.

Based on the above, the light source module 500 shown in FIG. 5 includes the porous optical film 130, and the porous optical film 130 has a plurality of first holes FH disposed in the central region CR, and the second holes SH are disposed in the peripheral region PR. Further, the hole arrangement of the porous optical film 130 also needs to satisfy the above conditions. Therefore, the light source module 500 can be used to uniformize the brightness of the screen while reducing the problem of chromatic aberration.

In the embodiment of FIGS. 3A to 5, the coating layer 140 is provided only in the central region CR of the porous optical film 130, but the present invention is not limited thereto. For example, in another embodiment, the coating layer 140 further includes a peripheral region PR disposed in the porous optical film 130. Similarly, the configuration of the coating layer 140 in the peripheral region PR can be changed with reference to the embodiment of FIGS. 3A to 5. Further, in the present embodiment, when the thickness of the porous optical film 130 is t, the thickness of the coating layer 140 on the upper surface or the lower surface of the porous optical film 130 is 0.14 t to 0.26 t. [Example]

Next, as shown in Tables 1 to 3, the relationship between the opening area of the porous optical film 130 in the central region CR and the above H1/H2 is defined.

Table 1

Table 2

table 3

From the examples of Tables 1 to 3, it can be found that when the distance at which H1 and H2 are added decreases, the open area ratio of A2/A1 increases. Conversely, if the distance between H1 and H2 increases, the open area ratio of A2/A1 will become smaller. The experimental results show that in the central region, when the open area ratio of A2/A1 is 0.5% to 25%, the color difference conversion value can be controlled within the range of 0.001 to 0.020. In other words, when the hole arrangement of the porous optical film 130 and the distance between H1 and H2 satisfy the conditions of Tables 1 to 3 described above, the brightness of the screen presented by the light source module can be made uniform while reducing the problem of chromatic aberration. However, when the aperture area ratio of the A2/A1 is outside the range of 0.5% to 25%, the energy distribution or the brightness of the light source module tends to be uneven.

In addition, in the examples of Tables 1 to 3, the coating layer 140 may be used to fill the first holes FH, wherein the coating layer 140 has a haze of 10% to 40%. In detail, when the coating layer 140 fills the first hole FH, its thickness is 0.75 mm. In other words, the thickness of the coating layer 140 may be the same as the thickness of the porous optical film 130. If the coating layer 140 is on the first surface or the second surface of the porous optical film 130, the thickness of the coating layer 140 is 0.15 ± 0.05 mm. As described above, when the haze and the thickness of the coating layer 140 are controlled within the above range, the brightness of the screen can be further uniformed without affecting the chromatic aberration.

Furthermore, experimental results have found that when the optical film is added above or below the wavelength conversion optical film 120, it can be used to improve the problem of yellow halo. Therefore, those skilled in the art can refer to the present invention to add an optical film such as a brightness enhancement film, a double brightness enhancement film, a microlens sheet or the like above or below the wavelength conversion optical film 120 to further enhance the effect of the present invention.

In summary, the light source module of the present invention includes a porous optical film, and the porous optical film has a plurality of first holes disposed in the central region, and the second holes are disposed in the peripheral region. In addition, the hole arrangement of the porous optical film, and the distance between it and the diffusion plate and the light source are required to satisfy specific conditions. Therefore, the light source module of the present invention can be used to uniformize the brightness of the screen while reducing the problem of chromatic aberration.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100, 300A, 300B, 400A, 400B, 500‧‧‧ light source module
110‧‧‧Diffuser
120‧‧‧wavelength conversion optical film
130‧‧‧Porous optical film
140‧‧‧coating layer
LS‧‧‧ light source
Sub‧‧‧Substrate
FH‧‧‧ first hole
SH‧‧‧Second hole
CR‧‧‧Central Area
PR‧‧‧ surrounding area

1A to 1C are schematic cross-sectional views showing a light source module according to an embodiment of the present invention. 2 is a top plan view of a porous optical film according to an embodiment of the present invention. 3A is a cross-sectional view of a light source module according to another embodiment of the present invention. FIG. 3B is a cross-sectional view of a light source module according to another embodiment of the present invention. 4A is a cross-sectional view of a light source module according to another embodiment of the present invention. 4B is a cross-sectional view of a light source module according to another embodiment of the present invention. FIG. 5 is a cross-sectional view of a light source module according to another embodiment of the present invention.

100‧‧‧Light source module

110‧‧‧Diffuser

120‧‧‧wavelength conversion optical film

130‧‧‧Porous optical film

LS‧‧‧ light source

Sub‧‧‧Substrate

FH‧‧‧ first hole

SH‧‧‧Second hole

CR‧‧‧Central Area

PR‧‧‧ surrounding area

Claims (17)

A light source module comprising: a light source; a diffuser plate above the light source; a wavelength conversion optical film above the diffuser plate; and a porous optical film between the light source and the diffuser plate The porous optical film has a central region and a peripheral region around the central region, the central region being disposed corresponding to the light source, wherein the central region has at least one first hole, and the peripheral region has a plurality of second holes The apertures of the second holes are larger than the apertures of the first holes, wherein the area of the first holes accounts for 0.5~25% of the area of the central area. The light source module of claim 1, wherein the area of the first hole occupies 0.5 to 15% of the area of the central area. The light source module of claim 1, wherein a vertical distance between the porous optical film and the light source is H1, and a vertical distance between the porous optical film and the diffusion plate is H2, and H2 /H1=0.5~1.5. The light source module according to claim 1, wherein in the porous optical film, a horizontal distance X ₀ corresponding to a center point of the light source to an outermost side of the central region satisfies: X ₀ > (H1) ×a ₀ )/t, H1 represents a vertical distance between the porous optical film and the light source, a ₀ represents an aperture of the second hole that is in the outermost side of the central region, and t represents the porous optical The thickness of the film. The light source module of claim 4, wherein the central area has an area ranging from a center of the light source to a diameter of 2× ₀ . The light source module of claim 1, wherein the aperture a of the first hole satisfies: a ≧ (X*t) / H1, where X represents a light source corresponding to the light source. A horizontal distance from a center point to any of the first holes, H1 represents a vertical distance between the porous optical film and the light source, and t represents the thickness of the porous optical film. The light source module of claim 1, further comprising a coating layer disposed in the central region of the porous optical film, wherein the coating layer comprises a wavelength conversion material, a diffusion material or combination. The light source module of claim 7, wherein the coating layer is filled in the first hole. The light source module of claim 7, wherein the porous optical film has a first surface and a second surface, the first surface facing the diffusion plate, the second surface facing the light source, the coating A layer of cloth is on the first surface. The light source module of claim 9, wherein the coating layer is located on the first surface and filled in the first hole. The light source module of claim 7, wherein the porous optical film has a first surface and a second surface, the first surface facing the diffusion plate, the second surface facing the light source, the coating The cloth layer is on the second surface. The light source module of claim 11, wherein the coating layer is located on the second surface and filled in the first hole. The light source module of claim 7, wherein the surface of the coating layer has a ruthenium pattern, a microlens pattern or a roughened pattern. The light source module of claim 7, wherein the coating layer further comprises a peripheral region disposed in the porous optical film. The light source module of claim 1, wherein a center line of the light source extends through the first hole of the porous optical film. The light source module of claim 7, wherein the coating layer has a haze of 10% to 40%. The light source module of claim 1, wherein the material of the wavelength conversion optical film comprises a quantum dot as a base material or a phosphorescent material.