CN105891919B - Light transmitting base material - Google Patents

Abstract

The invention discloses a light transmission substrate, which comprises a body with a first surface and a protruding part, wherein the protruding part is positioned on the first surface and protrudes out of the first surface; the protrusion has an irregular top land surface and an inclined surface, wherein the inclined surface is connected to the first surface and the irregular top land surface, a height from the irregular top land surface to the first surface is 5 to 40 μm, and a longest top land width of the irregular top land surface is 0.15 to 8 mm. The light transmissive base material of the present invention can maintain high luminance and improve luminance uniformity when applied as a diffuser plate.

Description

light-transmitting substrate

technical field

The present invention relates to a light-transmitting base material, and particularly relates to a light-transmitting base material having protrusions which can be used as a diffusion plate.

Background technique

The diffuser plate is an optical plate used in electronic products such as displays. Its main function is to diffuse and atomize the light from the light source, so that the product screen presents a picture quality with uniform brightness. Different electronic products have different requirements for screen quality. Therefore, diffuser manufacturers manufacture diffuser panels with different light transmittances according to the requirements of downstream manufacturers. Taking a side-facing backlight module applied to a display (such as a liquid crystal display device) as an example, it generally includes a light guide plate formed of a light-transmitting material, and a light source (such as a line light source formed by a cold cathode tube) arranged at the side end of the light guide plate. , a light reflection film located under the light guide plate and the line light source, and a diffusion plate and/or a lens film (lens film) arranged on the light guide plate to form a light-emitting surface.

In order to improve brightness and reduce power consumption, in recent years, in color liquid crystal display devices, one or two lens films with prism-shaped surfaces are arranged on the top of the diffuser plate or between the diffuser plate and the light guide plate. The light emitted from the light guide plate is efficiently focused on the front direction of the liquid crystal panel. In addition, in order to improve the unevenness of light emission caused by the distance from the light source, there is also a technique of printing light-diffusing ink on the inside of the light guide plate to form a dot pattern that becomes larger as it moves away from the light source. However, the configuration of the diffuser plate The main purpose is to diffuse the light uniformly and make the dot pattern printed on the inside of the light guide plate invisible. However, such lens films have conventionally been produced by methods such as embossing a thermoplastic resin plate or transferring a prism shape using a radiation-curable resin. However, the manufacturing cost of these existing lens films is high, which is considered to be the main reason for the high price of the backlight module. In addition, the existing lens films are limited in their manufacturing methods so that the material selection range is too narrow. Furthermore, the lens film must be used in combination with the light diffusion film because it has no light diffusion effect, resulting in the problem of complicated assembly steps of the backlight module.

In addition, in addition to the above-mentioned diffusion plate in the display, various functional films such as diffusion film, lens film, and brightness enhancement film may be used to improve the brightness of the display screen and reduce the brightness unevenness of the entire screen. In order to achieve the purpose of thinning and reducing the cost of the display, there are currently many studies focusing on the development of optical plates that integrate multiple functions, such as integrating the light diffusion effect of the diffuser plate and the light collection effect of the brightness enhancement film into one optical plate. Research. In particular, as displays (such as liquid crystal televisions) have recently progressed from small to large sizes, it is more desirable to develop an optical diffuser that can reduce the number of functional films used while improving luminance and diffusion performance.

Contents of the invention

The object of the present invention is to provide a light transmissive plate, which can maintain high luminance and improve the uniformity of luminance when it is applied as a diffuser plate.

To achieve the above object, the present invention provides a light-transmitting substrate, comprising a main body with a first surface, and a protrusion (protrusion) located on the first surface and protruding from the first surface . The protruding portion has an irregular platform top surface and an inclined surface, wherein the inclined surface is connected to the first surface and the irregular platform top surface. The top surface of the irregular-shaped platform has a height (Hp) of 5 μm-40 μm from the first surface, and the longest platform width (Wm) of the top surface of the irregular-shaped platform is 0.15 mm-8 mm.

Wherein, the light-transmitting substrate has a thickness ranging from 0.5 mm to 6 mm.

Wherein, a width (Ws) of the vertical projection of the slope on the first surface is 10 μm˜160 μm.

Wherein, an included angle between the slope and the first surface ranges from 120 degrees to 177 degrees.

Wherein, the irregular top surface of the platform means that the projection of the protrusion on the first surface in the thickness direction of the main body is irregular.

Wherein, the light-transmitting base material is composed of a light-transmitting resin.

Wherein, a plurality of diffusion particles are dispersed in the main body and the protruding part, and the average particle diameter of the plurality of diffusion particles is 0.1 μm˜30 μm.

Wherein, the average particle diameter of the plurality of diffusion particles is 0.5 μm˜20 μm.

Wherein, the average particle diameter of the plurality of diffusion particles is 1 μm˜5 μm.

Wherein, there are a plurality of protrusions on the first surface of the body, and the minimum distance between adjacent protrusions is in the range of 10 μm˜1000 μm.

Wherein, the portion of the first surface other than the protrusion has a surface roughness (Ra) of 0.1 μm or less, and the top surface of the irregular platform of the protrusion has a surface roughness (Ra) of 0.5 μm or less.

Wherein, the part of the first surface other than the protrusion has a surface roughness (Ra) of 0.01 μm to 0.08 μm, and the top surface of the irregular platform of the protrusion has a surface roughness (Ra) of 0.01 μm ~0.3 μm.

Wherein, the part of the first surface other than the protrusion has a surface roughness (Ra) of 0.02 μm to 0.07 μm, and the top surface of the irregular platform of the protrusion has a surface roughness (Ra) of 0.03 μm ~0.25 μm.

Wherein, the body further has a second surface opposite to the first surface, and the surface roughness (Ra) of the second surface is in the range of 3 μm˜30 μm.

Wherein, the first surface is a light incident surface, and the second surface is a light output surface.

Wherein, the light transmittance of the light-transmitting substrate is 50% to 70%.

Wherein, the body and the protrusion are integrally formed.

Wherein, the top surface of the irregular platform of the protrusion is parallel to the first surface of the body.

Wherein, the protruding portion has opposite first and second slopes at the position corresponding to the longest platform width to connect the first surface and the top surface of the irregular platform respectively, and the first slope and the second slope are respectively connected to the top surface of the irregular platform. The first surface forms a first included angle and a second included angle, wherein the first included angle is different from the second included angle.

Wherein, the protruding portion has opposite first and second slopes at the position corresponding to the longest platform width to connect the first surface and the top surface of the irregular platform respectively, and the first slope and the second slope are respectively connected to the top surface of the irregular platform. The first surface forms a first included angle and a second included angle, wherein the first included angle is equal to the second included angle and is respectively within a range of 120 degrees to 177 degrees.

Wherein, the top surface of the irregular platform has a minimum platform length perpendicular to the longest platform width, and the minimum platform length is 0.03mm˜1.5mm.

Wherein, the protruding portion accounts for 35%-70% of the area of the first surface.

Wherein, the area/perimeter ratio of the protruding portion ranges from 100 μm to 180 μm.

To achieve the above object, the present invention further provides a backlight module, comprising: a light source; and the above-mentioned light-transmitting substrate, wherein the light source is disposed opposite to the first surface.

Wherein, the first surface is a light incident surface.

The backlight module of the present invention includes a light-transmitting substrate according to an embodiment, and has high luminance and high luminance uniformity.

To achieve the above object, the present invention also provides a display, comprising: the aforementioned backlight module.

The display of the present invention, including the backlight module with the light-transmitting substrate of an embodiment, has high luminance and high luminance uniformity.

Compared with the prior art, the light transmissive plate proposed by the present invention has a specially designed protrusion, which can maintain high luminance and improve luminance when used as a diffuser plate. Uniformity of luminance.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Description of drawings

FIG. 1 is a partial top view of a light-transmitting substrate according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a protruding portion of the light-transmitting substrate of the embodiment.

FIG. 3A is a schematic view of a part of the light-transmitting substrate of Experimental Example 1 photographed with an optical microscope.

FIG. 3B is a schematic view of a part of the light-transmitting substrate of Experimental Example 2 photographed with an optical microscope.

FIG. 3C is a schematic diagram of partially photographing the light-transmitting substrate of Experimental Example 5 with an optical microscope.

FIG. 3D is a schematic diagram of partially photographing the light-transmitting substrate of Experimental Example 6 with an optical microscope.

FIG. 3E is a schematic diagram of partially photographing the light-transmitting substrate of Experimental Example 7 with an optical microscope.

FIG. 3F is a schematic view of a part of the light-transmitting substrate of Experimental Example 8 photographed with an optical microscope.

FIG. 3G is a schematic diagram of partially photographing the light-transmitting substrate of Experimental Example 9 with an optical microscope.

FIG. 3H is a schematic diagram of partially photographing the light-transmitting substrate of Experimental Example 10 with an optical microscope.

FIG. 4 shows the roughness curve of a part of the surface of the comparative example obtained by directly measuring the surface of the comparative example with a laser conjugation focal instrument.

FIG. 5A shows the roughness curve of the platform top surface of the protrusion obtained by directly measuring the surface of the protrusion of the light-transmitting substrate of Experimental Example 1 with a laser confocal instrument.

FIG. 5B shows a roughness curve obtained by directly measuring the first surface of the main body other than the protruding part of the light-transmitting substrate of Experimental Example 1 with a laser confocal instrument.

FIG. 6A shows the roughness curve of the platform top surface of the protruding part obtained by directly measuring the surface of the protruding part of the light-transmitting substrate in Experimental Example 2 with a laser confocal instrument.

FIG. 6B shows a roughness curve obtained by directly measuring the first surface of the main body other than the protruding part of the light-transmitting substrate of Experimental Example 2 with a laser confocal instrument.

FIG. 7 is a schematic diagram of a backlight module according to an embodiment of the present invention.

Among them, reference signs:

1: Light-transmitting base material

10: Ontology

101: the first surface of the body

102: the second surface of the body

20: protrusion

201: Irregular platform top surface of protrusion

203: first bevel

204: second bevel

(180－α1)°: the first included angle

(180－α2)°: the second included angle

Hp: the height from the top surface of the irregular platform to the first surface

Hm: Thickness of the body

Ws: the vertical projection width of the slope of the protrusion on the first surface

Wm: The longest platform width of the irregular platform top surface of the protrusion

Dm: minimum platform length perpendicular to the longest platform width

d: the minimum distance between two adjacent protrusions

700: backlight module

710: Diffusion plate

720: light source

722: Substrate

724: Luminous unit

740: frame

742: Storage space

X, Y, Z: direction

Detailed ways

Embodiments of the present invention provide a light transmissive plate, which can be applied to a display device as a diffuser plate of a backlight module. The light-transmitting substrate of the embodiment uses the protrusion formed on the surface of the main body and its special design to maintain high luminance in the light-emitting area of the display device and improve the uniformity of luminance. Therefore, according to the embodiment, a diffuser plate with high luminance and improved diffusion performance can be provided, reducing the number of other traditionally used functional films, thereby reducing the cost and making the application display more light and thin (especially a large-sized display). When the light-transmitting base material of the embodiment is used as a diffuser plate, the surface of the main body having the protruding portion faces the light source of the backlight module.

Embodiments are described in detail below with reference to the accompanying drawings. It should be noted that the structures and contents provided in the embodiments are for illustration purposes only, and the protection scope of the present invention is not limited to the above-mentioned aspects. In the embodiments, the same or similar symbols are used to indicate the same or similar parts. It should be noted that not all possible embodiments of the present invention are shown. Changes and modifications can be made to the structure without departing from the spirit and scope of the present invention to meet the needs of practical applications. Therefore, other implementation aspects not proposed in the present invention may also be applicable. Furthermore, the drawings have been simplified to clearly illustrate the content of the embodiments, and the size ratios in the drawings are not drawn according to the proportion of the actual product. Therefore, the specification and illustrations are only used to describe the embodiments, not to limit the protection scope of the present invention.

FIG. 1 is a partial top view of a light-transmitting substrate according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a protruding portion of the light-transmitting substrate of the embodiment. Please refer to Figure 1 and Figure 2 at the same time. The light-transmitting substrate 1 of the embodiment includes a main body 10 and a protrusion 20 located on a first surface 101 of the main body 10 and protruding from the first surface 101 . Wherein, the body 10 and the protruding portion 20 are integrally formed. Taking a single protruding part 20 as an example, the protruding part 20, for example, is island-shaped, has an irregular platform top surface 201 and slopes (203, 204), wherein the slopes (203, 204) are connected to the first surface 101 and the irregular platform Top surface 201 .

Wherein, the irregular platform top surface 201 means that the projection of the protruding portion 20 toward the thickness direction of the main body 10 on the first surface 101 is irregular, as shown in FIG. 2 . In one embodiment, the irregular-shaped platform top surface 201 of the protrusion 20 has a height Hp from the first surface 101 , and the height Hp ranges from 5 μm to 40 μm, preferably 10 μm to 35 μm.

The thickness of the light-transmitting substrate 1 is the thickness Hm of the main body 10 plus the height Hp of the protruding portion 20. When the light-transmitting substrate 1 of the present invention is used as a diffuser for a backlight module, the light-transmitting The thickness of the substrate 1 is preferably 0.5 mm to 6 mm. If the thickness exceeds 6mm, it may be unsuitable for use in today’s light and thin displays due to its excessive thickness and weight. When the thickness is thinner than 0.5mm, it may affect the diffusion effect during application due to insufficient rigidity. In one embodiment, the thickness of the light-transmitting substrate 1 ranges from 0.6 mm to 5 mm (600 μm to 5000 μm); in another embodiment, the thickness of the light-transmitting substrate 1 is 0.8 mm to 3 mm. In another embodiment, the thickness of the light-transmitting substrate 1 is 0.8 mm˜2.5 mm.

Since the height Hp of the protruding portion 20 is very small compared to the thickness Hm of the main body 10, the thickness of the light-transmitting substrate 1 (that is, the thickness Hm of the main body plus the height Hp of the protruding portion 20) can be considered to be approximately or equal to the thickness of the main body 10. The thickness Hm.

Referring to FIG. 2 , a width Ws of the vertical projection of the slope ( 203 , 204 ) of the protruding portion 20 on the first surface 101 is in the range of 10 μm˜160 μm, preferably in the range of 12 μm˜150 μm. In one embodiment, a width Ws of the vertical projection of the slope ( 203 , 204 ) of the protruding portion 20 on the first surface 101 is, for example, within a range of 13 μm˜40 μm. In another embodiment, a width Ws of the vertical projection of the slope ( 203 , 204 ) of the protruding portion 20 on the first surface 101 is, for example, within a range of 90 μm˜150 μm. In one embodiment, the included angle (180-α1, 180-α2) between the slope (203, 204) and the first surface 101 ranges from 120° to 177°, preferably 125° to 175° .

Quite different from the microstructure of existing diffuser plates, the embodiment has protrusions 20 of larger size. In one embodiment, a longest platform width Wm of the irregular platform top surface 201 of the protrusion 20 is in the range of 0.15 mm˜8 mm (150 μm˜8000 μm). In another embodiment, the longest platform width Wm of the irregular platform top surface 201 of the protrusion 20 is 0.175mm˜7mm. In yet another embodiment, the longest platform width Wm of the irregular platform top surface 201 of the protruding portion 20 is 0.2 mm˜6 mm.

In one embodiment, the top surface of the irregular platform has a minimum platform length Dm perpendicular to the longest platform width, and the range is 0.03 mm˜1.5 mm.

Moreover, in one embodiment, the first surface 101 of the body 10 (that is, the first surface portion other than the protrusion 20 ) has a surface roughness (Ra) of 0.1 μm or less, preferably 0.085 μm or less, for example, 0.01 μm or less. In the range of μm～0.08μm. . In one embodiment, the platform top surface 201 of the protruding portion 20 has a surface roughness (Ra) of less than 0.5 μm, preferably less than 0.3 μm, such as in a range of 0.01 μm˜0.3 μm. In one embodiment, the first surface 101 of the body 10 has a surface roughness (Ra) of 0.02 μm to 0.07 μm on the first surface portion other than the protrusion 20, and the platform top surface 201 of the protrusion 20 has a surface roughness (Ra) is 0.03 μm to 0.25 μm. The body 10 of the light-transmitting substrate 1 further has a second surface 102 opposite to the first surface 101 . In one embodiment, the surface roughness (Ra) of the second surface 102 of the body 10 is in the range of 3 μm˜30 μm. In another embodiment, the surface roughness (Ra) of the second surface 102 of the body 10 is in the range of 4 μm˜25 μm. The surface roughness Ra can be measured with a 3D shape microscope.

One embodiment of the present invention will be further described below with reference to FIG. 1 and FIG. 2 , but the present invention is not limited thereto.

As shown in FIG. 1 , the light-transmitting substrate 1 has a plurality of protruding parts 20 located on the first surface 101 of the body 10 and protruding from the first surface 101. The minimum distance between two adjacent protruding parts 20 (that is, the protruding parts 20 The distance (d) from the protruding portion 20 is in the range of 0.01 mm to 1 mm (10 μm to 1000 μm), preferably 0.015 mm to 0.95 mm (15 μm to 950 μm).

As shown in FIG. 2 , in one embodiment, the single protruding portion 20 includes an irregular platform top surface 201 away from the first surface 101 of the body 10, and has an opposite first slope 203 and a corresponding longest platform width Wm. The second slope 204 . The first slope 203 and the second slope 204 respectively connect the first surface 101 and the irregular platform top surface 201 . The shapes of the irregular platform top surfaces 201 of the plurality of protrusions 20 may be the same or different from each other. And the first slope 203 and the second slope 204 respectively form a first included angle (180-α1)° and a second included angle (180-α2)° with the first surface 101 . In one embodiment, the first included angle (180−α1)° of the protruding portion 20 is different from the second included angle (180−α2)°, that is, α1≠α2. In another embodiment, the first included angle (180-α1)° of the protrusion 20 is equal to the second included angle (180-α2)°, that is, α1=α2.

However, the present invention is not limited to this, and the included angles between the slopes at different positions of the protrusions 20 and the first surface 101 may be the same or different; and the angles of the slopes of different protrusions 20 may be the same or different. Slight changes and adjustments are made depending on the needs of actual applications. In one embodiment, the first included angle (180-α1)° and the second included angle (180-α2)° are respectively in the range of 120°-177°. In another embodiment, the included angles of the slopes at different positions of the single protruding portion 20 relative to the first surface 101 are, for example, in the range of 120 degrees to 177 degrees. In addition, in one embodiment, the irregular platform top surface 201 of the protruding portion 20 is substantially parallel to the first surface 101 of the main body 10 .

In the embodiment, the light-transmitting substrate 1 is made of light-transmitting material, such as a light-transmitting resin. Translucent resins that can be used such as polycarbonate (polycarbonate), polystyrene (PS), polymethyl methacrylate (PMMA), methyl methacrylate-styrene copolymer (MS copolymer), acrylonitrile - Styrene copolymer (AS copolymer), cyclic polyolefin (cyclo-olefin copolymer), polyolefin copolymer (such as poly-4-methyl-1-pentene), polyethylene terephthalate ( polyethylene terephthalate), polyester, polyethylene, polypropylene, polyvinyl chloride, ionomer, etc. Among them, polycarbonate, polystyrene, polymethyl methacrylate, and methyl methacrylate-styrene copolymer are preferred.

In an embodiment, the light-transmitting substrate 1 may further include a plurality of diffusing particles dispersed in the main body and the protruding portion, such as transparent microparticles used as a light diffusing agent.

In the embodiment, the transparent diffusion particles are, for example, inorganic particles represented by glass particles, organic particles such as polystyrene resin, (meth)acrylic resin, silicone resin, etc., and organic particles are preferred. The organic microparticles are preferably bridged organic microparticles. During the manufacturing process, at least part of the bridges will not be deformed during the processing of the light-transmitting resin, and the state of microparticles can be maintained. That is, microparticles that do not melt into the translucent resin even when heated to the molding temperature of the translucent resin are preferred, and organic microparticles of bridged (meth)acrylic resins and silicone resins are more preferable. In one embodiment, particularly suitable transparent particles (diffusion particles) are, for example, polymer microparticles poly(butyl acrylate) core/poly(methyl methacrylate) based on partially bridged methyl methacrylate A polymer with a shell, a polymer with a core/shell type (manufactured by Rohm andHass Company, trade name Paraloid EXL-5136) with a core and shell comprising a rubber-like vinyl polymer, and a polymer with a bridging silicone Alkyl silicone resin [manufactured by Toshiba Silicone Co., Ltd., trade name Tospearl 120].

In one embodiment, the average particle size of the diffusion particles is 0.1 μm˜30 μm. In another embodiment, the average particle size of the diffusion particles added to the light-transmitting substrate 1 is 0.5 μm˜20 μm. In yet another embodiment, the diffusion particles added to the light-transmitting substrate 1 have an average particle size of 1 μm˜5 μm. The average particle size of the diffusion particles is preferably not protruding from the surface of the main body 10/protruding portion 20 . Furthermore, in one embodiment, the light transmittance of the light-transmitting substrate 1 is 50%-70%, preferably 55%-65%.

In addition, the average particle diameter of these transparent microparticles used as diffusing particles is the weight average particle diameter measured by the particle counting method, and the particle number and particle size distribution analyzer MODEL Zm of Nikoki Co., Ltd. can be used as the measuring device. When the weight average particle size is less than 0.1 μm, sufficient light diffusibility cannot be obtained and the luminescence of the light emitting surface is poor, and when it exceeds 30 μm, sufficient light diffusivity cannot be obtained and the luminescence of the light emitting surface is poor. The light-diffusing effect increases the compounding amount, which leads to a disadvantage in that the light transmittance is impaired.

Moreover, the usage-amount of transparent microparticles|fine-particles is 0.1-20 weight part based on 100 weight part of translucent resins, and it is especially suitably 0.5-12 weight part. When the amount of transparent fine particles used is less than 0.1 parts by weight, the light diffusivity is insufficient, that is, the problem that the light source can be seen through penetration. On the other hand, when the usage-amount of transparent fine particle exceeds 20 weight part, light transmittance will fall, and luminance will deteriorate.

In one embodiment, the light-transmitting substrate 1 can use polystyrene (PS) (for example: Taiwan Chimei GPPS PG-383D) light-transmitting resin and add transparent microparticles (such as the above-mentioned diffusion particles), and any The method or device is to make this combination into a single layer to form a substrate 1 (i.e. a light diffusion plate). In an embodiment, for example, a melt-extrusion method is used to form a plate-like structure with a predetermined thickness. When extruding by melt, it is best to extrude after the melting zone of the extruder is decompressed to 1.33-66.5kPa. If the melting zone of the extruder is not decompressed, the mixed transparent microparticles, especially the infusible acrylic polymer microparticles, will be affected by oxygen, which may cause partial collapse of the particle surface and reduce the light diffusion performance. In addition, conventionally known methods can also be used, such as injection molding, injection compression molding, blow molding, compression molding, powder molding, etc., can complete the molding of the optically transparent base material 1 .

In addition, instead of being made of a single-layer board, the light-transmitting substrate 1 of the present invention can also be a multi-layer board, for example, besides the above-mentioned light-transmitting resin layer, a coating layer can also be included. In one embodiment, the thickness of the covering layer is 0.01mm˜0.5mm, or 0.02mm˜0.4mm, or 0.03˜0.3mm. If the thickness of the coating layer exceeds 0.5 mm, there may be a problem that the thickness of the backlight module unit cannot sufficiently meet the demand for thinning the liquid crystal display device due to the increase in the thickness of the backlight module unit. Furthermore, this coating layer has high transparency that can fully exert the lens effect, and the resin that can be used is an acrylic resin, such as polymethyl methacrylate, methyl methacrylate-styrene, acrylonitrile-styrene, etc. . Among them, polymethyl methacrylate and methyl methacrylate-styrene are preferred.

In addition, the composition of the light-transmitting substrate 1 may further include the addition of a UV absorber to improve the weather resistance of the light-transmitting substrate 1 and block harmful ultraviolet rays; and/or may further include the addition of a fluorescent agent , The fluorescent agent has the function of absorbing the energy of the ultraviolet part of the light and radiating the energy to the visible part.

In an embodiment where the light-transmitting substrate 1 is a multi-layer board, 0.5 to 15 parts by weight of an ultraviolet absorber is contained in 100 parts by weight of the acrylic resin forming the above-mentioned covering layer, and 0.1 parts by weight of an average particle diameter can be added as required. 0.1-20 parts by weight of transparent fine particles of μm-30 μm, and 0.001-0.1 parts by weight of fluorescent agent. Wherein the transparent fine particles are as described above in the diffusion plate, and the usage amount of the transparent fine particles is preferably 0.5-12 parts by weight.

In one embodiment, the ultraviolet absorber is for example: a benzophenone-based ultraviolet absorber of 2,2'-dihydroxy-4-methoxybenzophenone, 2-(4,6-diphenyl-1, 3,5-triazine-2-substituent)-5-hexylhydroxyphenol triazine UV absorber, 2-(2H-benzotriazole-2-substituent)-4-methylphenol, 2- (2H-benzotriazole-2-substituent)-4-tertoctylphenol, 2-(2H-benzotriazole-2-substituent)-4,6-bis(1-methyl-1 -Phenylethyl)phenol, 2-(2H-benzotriazole-2-substituent)-4,6-bis-third amylphenol, 2-(5-chloro-2H-benzotriazole- 2-substituent)-4-methyl-6-tert-butylphenol, 2-(5-chloro-2H-benzotriazole-2-substituent)-2,4-tert-butylphenol and 2,2'-methylenebis[6-(2H-benzotriazole-2-substituent)-4-(1,1,3,3-tetramethylbutyl)phenol] and other benzotri Azole UV absorber.

In one embodiment, preferred ultraviolet absorbers such as: 2-(2-hydroxyl-5-tolyl)benzotriazole, 2-(2-hydroxyl-5-tertiary octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dicumyl)phenylbenzotriazole, 2-(2-hydroxy-3-tert-butyl-5-tolyl)-5-chlorobenzotriazole Azole, 2,2'-methylenebis[4-(1,1,3,3 tetramethylbutyl)-6-(2H-benzotriazole-2-substituent)phenol], 2-[ 2-Hydroxy-3-(3,4,5,6-tetrahydrophthalimidemethyl)-5-tolyl]benzotriazole. Among them, 2-(2-hydroxyl-5-tertiary octylphenyl)benzotriazole (manufactured by Ciba-Geigy, trade name Tinuvin 329), 2,2'-methylenebis[4-(1, 1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-2-substituent)phenol] is preferred.

Furthermore, when using an ultraviolet absorber in the examples, one component can be selected alone or two or more components can be used in combination, and it is better to use 0.5 to 15 parts by weight relative to 100 parts by weight of the acrylic resin, and 1 to 10 parts by weight. Parts by weight are better. When the amount used is less than 0.5 parts by weight, the weather resistance is poor and the hue changes greatly. When the amount used is more than 15 parts by weight, the color tone and brightness will be deteriorated.

In addition, the fluorescent agent used in the examples (which has the function of absorbing the energy of the ultraviolet portion of light and radiating the energy to the visible portion) is used to convert synthetic resins, etc., within the range that does not impair optical resistance. The color tone is improved to white or blue-white, such as stilbene, benzimidazole, benzoxazole, phthalimide, rose bengal, coumarin, oxazole, etc. In one embodiment, the usage amount of the fluorescent agent is, for example, in the range of 0.001-0.1 parts by weight relative to 100 parts by weight of the acrylic resin, and preferably in the range of 0.002-0.08 parts by weight. By blending the fluorescent agent within the above-mentioned range, sufficient luminescence and color tone improvement effects can be obtained on the light-emitting surface.

<Related experiments>

Several groups of related experiments and their data are listed below for description of the examples. Please refer to the above content and FIGS. 1 and 2 for the structure of the light-transmitting substrate 1 . In the experiment, in order to propose several groups of samples, and the specifications of each sample are as follows:

Comparative example: a commercially available diffuser plate DS601A (Chi Mei Corporation), the surface of the diffuser plate does not have any island-shaped protrusions as in the embodiment.

The light-transmitting substrates of Experimental Examples 1, 2, 5-7, and 9 had a thickness of 1.2 mm; the light-transmitting substrates of Experimental Examples 3, 4, 8, and 10 had a thickness of 2.2 mm. Experimental examples 1-10 all include a plurality of island-shaped protrusions 20 formed on and protruding from the first surface 101 of the body 10 , and the protrusions 20 and the body 10 are integrally formed.

Brightness, average four-corner uniformity:

In order to use the luminance meter of model BM-7A manufactured by Japan Topcon Corporation (TOPCON CORPORATION) to carry out the measurement, and during the measurement, the light diffusion plates of the experimental examples 1-10 and the comparative example were set in an LED light source array. Luminance measurement is performed on the light box module. Wherein, the luminance (luminance) value is a value after normalization, that is, a value after normalizing the central luminance measurement value of Experimental Examples 1 to 10 with the central luminance measurement value of Comparative Example being 100%. The average four-corner uniformity is the average value of the last four values obtained by dividing the luminance of the four corners of the module by the central luminance of the module.

Roughness:

The roughness is measured by using the laser conjugation focal meter (model VK-X100Series) of KEYENCE Company as a microstructure measuring instrument, according to the method described in JIS B0601-2001, within a 10mm×10mm block, a random amount Measure the roughness parameter Ra or Rz obtained by measuring the roughness curve obtained by measuring the surface roughness at a magnification of 50 times; where Rz represents the difference data between the highest point and the lowest point.

The height (Hp) from the top surface of the platform to the first surface, the vertical projection width (Ws) of the inclined plane, and the included angle of the inclined plane:

The cross-sectional curves of Experimental Examples 1-10 and Comparative Examples were obtained by directly measuring the surfaces of Experimental Examples 1-10 and Comparative Example with a laser conjugation instrument. The cross-sectional curves were taken from the longest distance between any two points on the surface of the platform ( That is, the longest platform width Wm), then measure the height (Hp) from the platform top surface 201 of the protrusion 20 to the first surface 101, and the vertical projection width (Ws) of the inclined plane of the protrusion 20 on the first surface 101, respectively. In the experimental example of this case, the measurement value of the vertical projection width (Ws) is a value extending along the left side of the longest platform width Wm, but it is not limited to this, that is, the vertical projection width (Ws) is the value along the longest platform width Wm Extend the value on one side of the platform width Wm, calculate the angles of α1 and α2 with trigonometric functions through the values of Hp and Ws, and then convert the included angle of the inclined plane with 180-α1 (or 180-α2).

Distance between two adjacent islands:

It uses KEYENCE's laser conjugation focal meter (model VK-X100Series) as a measuring instrument to randomly measure 20 points of data in a 10mm×10mm block, in which two adjacent island-shaped protrusions The minimum distance between two adjacent island-shaped protrusions_Max is expressed as the maximum value of the minimum distance between two adjacent island-shaped protrusions within the measurement range; the minimum distance between two adjacent island-shaped protrusions_Min is expressed as two phases within the measurement range The smallest of the measurements of the smallest distance between adjacent islands. The distance between two adjacent island-shaped protrusions ranges from 0.01 mm to 1 mm (10 μm to 1000 μm), preferably 0.015 mm to 0.95 mm (15 μm to 950 μm).

The longest platform width Wm and the minimum platform length Dm of the irregular platform top surface 201:

It uses KEYENCE's laser conjugate focal meter (model VK-X100Series) as a measuring instrument to randomly measure 20 points of data in a 10mm×10mm block to obtain the maximum distance between any two points on the surface of the platform. The range of the longest platform width Wm of the long distance and the range of the minimum platform length Dm perpendicular to the longest platform width Wm. The longest platform width Wm of the irregular platform top surface 201 of the protrusion 20 is in the range of 0.15 mm to 8 mm (150 μm to 8000 μm), preferably in the range of 0.155 mm to 7 mm, more preferably in the range of 0.158 mm to 6 mm In the range. The minimum platform length Dm of the irregular platform top surface 201 of the protrusion 20 is within the range of 0.03 mm to 1.5 mm, preferably within the range of 0.05 mm to 1.2 mm, more preferably within the range of 0.07 mm to 1.05 mm .

Area/perimeter of protrusion (μm), area ratio of protrusion (%):

By using the optical microscope (Optical Microscope, model Bx-60F5) of Olympus Company as the measuring instrument, the images in the block of 6.821mm×5.312mm (the area is 36.233mm ² ) were taken, and the analysis software (Image-Pro Plus ) Calculate the area and perimeter of each protrusion in this range and make statistics, the area of protrusion/perimeter (μm)=the total area of protrusions/perimeter sum of protrusions in the range; the area ratio of protrusions (%)=sum of the area of protrusions within the range/area of the measurement range (36.233mm ² ). Please refer to FIG. 3A to FIG. 3H , which respectively depict schematic diagrams of partially photographing the light-transmitting substrates of Experimental Examples 1, 2, and 5-10 with an optical microscope; wherein the light-transmitting substrates have a plurality of island shapes The protruding part protrudes from the first surface of the body, the outer frame curve of the protruding part is the area/perimeter measurement range, the thick frame part of the protruding part is the slope part, and the slightly rough part surrounded by the thick frame part is the platform top. In one embodiment, the area/perimeter of the protruding part is in the range of 100 μm˜200 μm, preferably in the range of 110 μm˜190 μm, more preferably in the range of 115 μm˜175 μm. In one embodiment, the area ratio of the protruding portion is in the range of 35%-70%, preferably in the range of 38%-68%, more preferably in the range of 40%-66%.

The above measurement results are recorded in Table 1 together.

Table 1

Table 1 (continued) (experimental example 6-10)

Please refer to FIG. 4 , which shows a roughness curve of a part of the surface of the comparative example obtained by directly measuring the surface of the comparative example with a laser confocal instrument. According to the measurement results, the current diffusion plate (comparative example) has no obvious difference between the top surface and the bottom surface, and they are all rough surfaces with many potholes with large height differences. The surface Rz of the two groups is 11.99 μm and 9.49 μm, which means that the surface of the current diffusion plate is very uneven.

Please refer to FIG. 5A and FIG. 5B at the same time. FIG. 5A shows a roughness curve of the platform top surface 201 of the protrusion 20 obtained by directly measuring the surface of the protrusion 20 of the light-transmitting substrate 1 in Experimental Example 1 with a laser confocal instrument. The platform top surface 201 of the protruding part 20 in Experimental Example 1 is roughly flat, with a few fine holes; the depth of the holes on the platform top surface 201 is measured, and two sets of Rz data are 0.52 μm and 0.41 μm. FIG. 5B shows a roughness curve obtained by directly measuring the first surface 101 of the main body 10 other than the protruding portion 20 of the light-transmitting substrate 1 of Experimental Example 1 with a laser confocal instrument. The first surface 101 of the body 10 other than the protruding portion 20 is also flat with few pits; the depth of the pits on the surface is measured, and two sets of Rz data are 0.95 μm and 0.98 μm.

Please refer to FIG. 6A and FIG. 6B at the same time. FIG. 6A shows the roughness curve of the platform top surface 201 of the protrusion 20 obtained by directly measuring the surface of the protrusion 20 of the light-transmissive substrate 1 in Experimental Example 2 with a laser confocal instrument. The platform top surface 201 of the protruding part 20 of Experimental Example 2 is very flat, with few potholes; the depth of the pits on the platform top surface 201 is measured, and two sets of Rz data are 0.49 μm and 0.61 μm. 6B shows a roughness curve obtained by directly measuring the first surface 101 of the body 10 of the light-transmitting substrate 1 in Experimental Example 2 except the protruding portion 20 with a laser confocal instrument. The first surface 101 of the body 10 other than the protruding portion 20 is also roughly flat with few pits; the depth of the pits on the surface is measured, and two sets of Rz data are 0.48 μm and 0.31 μm.

Please refer to FIG. 7 , which is a schematic diagram of a backlight module according to an embodiment of the present invention. The backlight module 700 of this embodiment is, for example, a direct-lit backlight module suitable for a flat panel display module, which includes a diffuser plate 710 , at least one light source 720 (a plurality of light sources are shown in FIG. 7 ) and a frame 740 . The frame defines an accommodating space 742 , the diffusion plate 710 and the light source 720 are located in the accommodating space 742 , and the diffusion plate 710 is placed above the light source 720 . The diffusion plate 710, for example, is the light-transmitting substrate of any one of the experimental examples 1 to 10 of the present invention, comprising a main body 10 with a first surface 101, and a main body 10 located on the first surface 101 and protruding from the first surface 101. A protrusion 20 of the first surface. The light source 720 is disposed opposite to the first surface 101 , that is, the first surface 101 is a light incident surface. The light source 720 includes a substrate 722 and a light emitting unit 724 . The light emitting unit 724 is, for example, a light emitting diode (LED) element or other types of light emitting elements and is disposed on the substrate 722 . The light emitted by the light emitting unit 724 enters the diffuser plate 710 and exits through the second surface 102 of the diffuser plate 710 to form a surface light source with high luminance and high luminance uniformity.

In one embodiment, the aforementioned backlight module 700 can be used as a backlight module of a display, such as a liquid crystal display.

Table 2 lists the measured data values of the distance between two adjacent island-shaped protrusions in the light-transmitting substrates of Experimental Example 1 and Experimental Example 2. It is measured randomly in a 10mm×10mm block by using the laser conjugate focal meter (model VK-X100Series) of KEYENCE Company as a measuring instrument, where the maximum value is expressed as the two phases within the measurement range The maximum value among the measured values of the minimum distance between adjacent island-shaped protrusions; the minimum value is the smallest value among the measured values of the minimum distance between two adjacent island-shaped protrusions within the measurement range.

Table 2

Table 3 lists the measured data values of the longest platform width Wm of the irregular platform top surface 201 of the island-shaped protrusion 20 in the light-transmitting substrates of Experimental Example 1 and Experimental Example 2. It is randomly measured in a 10mm×10mm block by using a laser conjugation focal meter (model VK-X100Series) from KEYENCE Company as a measuring instrument. Table 3 also lists the distance between the potholes with the difference in height and height on the surface of the comparative example measured by using a laser conjugate focal meter (model VK-X100 Series) from KEYENCE Company as a measuring instrument. The surface of the comparative example has a distance between potholes with height difference ranging from 5 μm to 50 μm.

table 3

Comparative example (μm) Experimental example 1 (μm) Experimental example 2 (μm) 1 33.27 984.22 2496.32 2 21.74 241.6 3875.68 3 18.51 291.07 1021.06 4 18.7 884.84 549.64 5 32.28 383.54 475.02 6 45.65 4271.6 464.37 7 15.68 2938.2 1321.52 8 22.01 558.68 3777.44 9 27.24 486.36 1449.19 10 17.99 2185.7 1912.42 11 20.65 5304.78 617.6 12 21.66 1010.92 2987.78 13 20.65 237.54 519.9 14 8.7 385.79 2946.14 15 10.87 646.49 1397.82 16 39.13 736.59 866.05 17 13.09 589.33 665.96 18 5.43 5904 1993.01 19 15.22 551.07 3165.52 20 19.23 912.23 4004.07

In summary, the light-transmitting substrate proposed in the embodiment has the above-mentioned specially designed protrusions formed on the surface of the main body. When the light-transmitting substrate (as shown in FIG. 1 ) of the embodiment is used as a diffuser plate, the first surface 101 on which the protruding portion 20 is formed faces the light source of the backlight module, so the first surface 101 is the light-incident surface , the second surface 102 of the main body 10 is a light-emitting surface. The application of the light-transmitting substrate of the embodiment not only maintains the high luminance of the light-emitting area of the display device, but also improves the uniformity of luminance compared with the existing diffusion plate. Therefore, using the light-transmitting substrate of the embodiment as a diffusion plate can not only improve the display effect of the image, but also reduce the number of other functional films used, reduce the manufacturing cost, and make the applied display become lighter and thinner as a whole, especially It has extremely high application value for large-scale displays.

Certainly, the present invention also can have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes All changes and modifications should belong to the protection scope of the claims of the present invention.

Claims (24)

1. A light-transmitting substrate, characterized in that it comprises: a body having a first surface; and A protruding part, the protruding part is integrally formed with the body, and the protruding part is located on the first surface and protrudes from the first surface, the protruding part has an irregular platform top surface and an inclined surface, and the inclined surface connects On the first surface and the top surface of the irregular platform, the top surface of the irregular platform has a height (Hp) of 5 μm to 40 μm from the top surface of the irregular platform, and a longest platform width of the top surface of the irregular platform (Wm) range is 0.15mm ~ 8mm; Wherein, the light-transmitting substrate has a thickness ranging from 0.5 mm to 6 mm. 2 . The light-transmitting substrate according to claim 1 , wherein a width (Ws) of the vertical projection of the slope on the first surface is in the range of 10 μm˜160 μm. 3 . 3 . The light-transmitting substrate according to claim 1 , wherein an included angle between the slope and the first surface ranges from 120° to 177°. 4 . 4 . The light-transmitting substrate according to claim 1 , wherein the irregular top surface of the platform means that the projection of the protruding portion on the first surface toward the thickness direction of the main body is irregular. 5. The light-transmitting substrate according to claim 1, wherein the light-transmitting substrate is composed of a light-transmitting resin. 6. The light-transmitting substrate according to claim 1, further comprising a plurality of diffusing particles dispersed in the main body and the protruding portion, the average particle diameter of the plurality of diffusing particles being 0.1 μm- 30 μm. 7. The light-transmitting substrate according to claim 6, wherein the plurality of diffusion particles have an average particle diameter of 0.5 μm˜20 μm. 8 . The light-transmitting substrate according to claim 6 , wherein the plurality of diffusion particles have an average particle diameter of 1 μm˜5 μm. 9. The light-transmitting substrate according to claim 1, characterized in that there are a plurality of protrusions on the first surface of the body, and the minimum distance between adjacent protrusions is between Between 10μm and 1000μm. 10. The light-transmitting substrate according to claim 1, wherein the portion of the first surface other than the protruding portion has a surface roughness of 0.1 μm or less, and the irregular platform of the protruding portion The top surface has a surface roughness of 0.5 μm or less. 11. The light-transmitting substrate according to claim 1, wherein the portion of the first surface other than the protruding portion has a surface roughness of 0.01 μm˜0.08 μm, and the irregularity of the protruding portion The top surface of the shaped platform has a surface roughness of 0.01 μm˜0.3 μm. 12. The light-transmitting substrate according to claim 1, wherein the portion of the first surface other than the protruding portion has a surface roughness of 0.02 μm˜0.07 μm, and the irregularity of the protruding portion The top surface of the shaped platform has a surface roughness of 0.03 μm˜0.25 μm. 13. The light-transmitting substrate according to claim 1, wherein the main body further has a second surface opposite to the first surface, and the surface roughness of the second surface is in the range of 3 μm˜30 μm between. 14. The light-transmitting substrate according to claim 13, wherein the first surface is a light incident surface, and the second surface is a light exit surface. 15. The light-transmitting substrate according to claim 1, wherein the light transmittance of the light-transmitting substrate is 50%-70%. 16. The light-transmitting substrate according to claim 1, wherein the top surface of the irregular platform of the protruding portion is parallel to the first surface of the main body. 17. The light-transmitting substrate according to claim 1, wherein the protruding portion has a first inclined surface and a second inclined surface corresponding to the longest platform width to connect the first surface and the non-identical surface respectively. The top surface of the regular platform, and the first slope and the second slope form a first angle and a second angle with the first surface respectively, wherein the first angle is different from the second angle. 18. The light-transmitting substrate according to claim 1, wherein the protruding portion has a first inclined surface and a second inclined surface corresponding to the longest platform width to connect the first surface and the non-identical surface respectively. The top surface of a regular platform, and the first slope and the second slope form a first angle and a second angle with the first surface respectively, wherein the first angle and the second angle are respectively in the range of 120 degrees to 177 degrees between degree ranges. 19. The light-transmitting substrate according to claim 1, wherein the top surface of the irregular platform has a minimum platform length perpendicular to the longest platform width, and the minimum platform length is 0.03 mm˜1.5 mm. 20 . The light-transmitting substrate according to claim 1 , wherein the protruding portion accounts for 35%-70% of the area of the first surface. 21 . 21 . The light-transmitting substrate according to claim 1 , wherein the area/perimeter ratio of the protruding portion ranges from 100 μm to 180 μm. 22. A backlight module, characterized in that it comprises: a light source; and The light-transmitting substrate according to any one of claims 1 to 21, wherein the light source is disposed opposite to the first surface. 23. The backlight module according to claim 22, wherein the first surface is a light incident surface. 24. A display, characterized in that it comprises: The backlight module of claim 22.