TW200538810A - Light diffusion plate for direct type backlight module and its manufacturing method - Google Patents

Abstract

The present invention provides a light diffusion plate in a direct type backlight module and its manufacturing method, in which the light diffusion plate and a light diffusing agent are extruded with an extruder. The optical resin material forming the light diffusion plate has an index of refraction different from that of the light diffusing material. A prism array having an angle corresponding to the used material is carved on the surface of the light diffusion plate. It is possible to refract incident light and control a reflected light angle by the index of refraction of the light diffusion plate and the prism structure formed on the surface, so as to collect diffused light again, reduce consumption of light and increase brightness. Moreover, the light diffusion plate can be formed as a one-dimensional, two-dimensional serrated, or nonequivalent two-dimensional shapes thereby decreasing the vertical and horizontal prisms needed.

Description

200538810 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a light diffusion plate of a direct type backlight module and a manufacturing method thereof, particularly a light diffusion plate, which is manufactured using a process A light diffusion plate with a cymbal effect. [Previous technology] As major manufacturers actively invest in research and development and use large-scale production equipment, the quality of liquid crystal displays continues to improve and prices continue to decline, making the application area of liquid crystal displays rapidly expanding. As L c D strives to open up new application areas, backlight technology with high brightness, low cost, low power consumption, and thinness also plays an important role. The backlight modules for general liquid crystal displays are mostly based on the method of edge light. It is composed of a light guide plate, a diffusion film, a reflective plate, and a cold cathode tube. ; The other is a direct type light source (direct type) 'usually used for large-size liquid crystal displays, higher brightness requirements, high uniformity requirements, at this time a thicker diffuser is used, which is provided due to its thickness It has better uniformity of brightness, and also has the rigidity of support that the film does not have. It includes a reflective sheet 10, a plurality of light sources 11, a light diffusion plate 12, and a first prism sheet 13. ', A second cymbal film 14, a brightness enhancement film 15', and the like as in the first picture 'There are many thin optical sheets combined, which not only increases the difficulty and time of their assembly, but also has a high cost. The backlight module has very poor directivity due to the role of the diffuser. For most computer monitors that only need to be viewed from the front, the use of light

200538810 V. Description of the invention (2) The efficiency is not high. Therefore, if a prism with a light-concentrating effect is added to the diffusion plate, such as the first prism sheet 1 3 ′ and the second diaphragm 1 4 ′ in the first figure, the output can be increased. The directivity of the emitted light can achieve the purpose of improving the front brightness. The sepals are generally made of polyester or polycarbonate as a material with a thickness of about 150 ~ 2 3 0 // m, and the spacing on the surface of the slice is 2 4 ~ 1 1 0 / / m, the apex angle is 9 0 ~ 1 1 0. The long stripe chirped array has the function of condensing due to its refractive index and its optical structure. When using a right-angled cymbal, the front brightness can be improved by 1.6 times. If two cymbals are arranged vertically, the front brightness can be improved by more than 2 times. In the past, UV-curing was used to mold on a mold or exhution was used to manufacture a prism sheet or diffusion plate. The film and the light source module are assembled together to become a backlight module. For example, U.S. Patent Nos. 5,1 7,5,0 3 0 and 5,1 3,5 9 7 are all on a transparent substrate, and Urester Or—Liquid resin is molded on a mold to make a cymbal; US Patent No. 5,831,774 is a transparent substrate coated with a diffusion layer and combined with the cymbal. ^ For backlight module manufacturers, the method of reducing costs is nothing more than simplifying the module structure, and the design of the top corner allows the light to be refracted forward, so the light energy is emitted from the surface of the diffuser plate, and it has an appropriate The degree of directivity improves the brightness of the front. This one-piece diffuser design can not only reduce expensive parts (such as cymbals) that need to be talked about, but also shorten assembly time, and at the same time

200538810 V. Description of the invention (3) To achieve the purpose of high brightness and cost reduction.

Therefore, how to propose a novel direct-type backlight module light diffusion plate and its manufacturing method to solve the above problems can not only improve the traditional need to assemble the diffusion plate, the cymbal, the brightness enhancement film and the light source module through assembly. The shortcomings can also increase the brightness and reduce the manufacturing process and reduce the cost. For a long time, users have been eagerly looking forward to the present inventor's intention, and the inventor has been engaged in research, development, and sales practice of related products based on many years. Experience, thoughts and ideas for improvement, and poor personal expertise, through various research and design, and special discussions, finally developed a light diffusion plate for direct-type backlight modules and improvements in manufacturing methods, which can solve the above problems. [Summary of the Invention] The main object of the present invention is to provide a light diffusion plate of a direct type backlight module and a manufacturing method thereof, which uses an extruder to extrude an optical resin and a light diffusing agent into a light diffusion plate. A light roller is used to roll the light diffusing plate, and the roller has a plurality of engravings to make it have a light diffusing plate with condensing effect.

A secondary object of the present invention is to provide a light diffusion plate of a direct type backlight module and a manufacturing method thereof. The engraving of the roller can be used to design chirp arrays with different angles according to the material used by the light diffusion plate. The refractive index and the chirped angle of the chirped structure refract the incident light, and then control the light emitting angle through the sawtooth plate surface, so that the light that has been diffused again is concentrated, the light loss rate is reduced, and the brightness is increased. In order to achieve the aforementioned purposes and effects, the present invention provides a

Page 7 200538810 V. Description of the invention (4) Light diffusion plate of direct type backlight module and manufacturing method thereof, which discloses a method for manufacturing a light diffusion plate combined with a stack of structures, using extrusion technology to be extruded by an extruder. A light diffusion plate, as the main material for uniformly diffusing the light source, the substrate can be PET, PC, PMMA, MS, ABS, or COC high-transparency optical resin, and 1 to 10 wt% light diffusing agent is added. The light diffusing agent can be PMMA, MS, ABS, PS, PU, containing Si02, Mg (0H) 2, CaC03,

BaSCU, A1203, TiO powder, to achieve the effect of light source diffusion. The light diffusing plate uses the refractive index of different materials, and the chirped array with different angles must be carved on the surface of the roller according to the used material. After the incident light is refracted by using the refractive index and the chirped angle of the chirped structure, The light-emitting angle is controlled by the jagged plate surface, so that the light that has been diffused again is concentrated again, and the light loss rate is reduced, so the brightness can be increased. After that, before the plate is cooled into plastic, the surface of the plate is rolled by a precision-rolled roller to make the surface layer into a structure, and it becomes a high-brightness diffuser that can concentrate the light source. By designing the light diffusion plate into a one-dimensional or two-dimensional dentate shape or a different one-dimensional shape ', the need for both horizontal and vertical diaphragms is reduced. Implementation mode] In order to make your review members have a better understanding and understanding of the structural features and achieved effects of the present invention, I would like to refer to the preferred embodiments and detailed descriptions as follows: The present invention is intended to solve the problem. Known technology The light diffusion plate needs to be assembled into a backlight module through assembly with a cymbal, a brightness enhancement film, and a light source module. This requires a complicated process. Therefore, the present invention uses an extruder to extrude an optical expansion plate.

Page 8 200538810 V. Description of the invention (5) ------- Loose plate 'Roll the light diffuser plate with a roller to make a person follow the path from the disaster relief surface of the diffuser plate 2. It has the function of condensing light, and according to the material of the light diffusion plate, it can adjust the engraving on the roller to recharge the light that has been diffused, reduce the light loss rate and increase the brightness. First, please refer to the second figure, which is a flowchart of a method for manufacturing a light diffusion plate of a direct type backlight module according to a preferred embodiment of the present invention; as shown, the present invention discloses a direct type The method for manufacturing a light diffusion plate of a backlight module includes the following steps: Step S10, using an extruder to heat an optical resin and a light diffusing agent to perform melting and mixing; and step S20, extruding and forming When a light diffusion plate is used, at least one surface of the light diffusion plate is rolled by a roller, wherein the surface of the roller has a plurality of engravings. The finished product of the light diffusion plate 1 is shown in FIG. 3A, and please refer to FIG. 3B and FIG. 3C together. The optical resin 10 is selected from the group consisting of polycarbonate and PMMA. , MS, ABS, PET, PETG, PS, M BS and C 0 C; the light diffusing agent 12 is selected from PMMA, MS, ABS, PS, PU, containing SiO2, Mg ( 0H) 2, CaC03,

BaS04, A1203, TiO powder. In addition, the light diffusion plate 1 may be added with one of an antistatic agent, an ultraviolet absorber, a flame retardant, and an antioxidant, or any combination thereof. The thickness of the light diffusion plate 1 is between 1 mm and 10 mm. After the light diffusing plate 1 is completed, the light diffusing plate 1 includes a plurality of apex angles 6 and a groove 14, and the angle 0 is 80 to 110 degrees. Furthermore, the distance between the apex angles is p, and the value of P is 5 to 2 0 0 / z m. And the third B picture is front view

200538810

V. Description of the invention (6), the third C is a three-dimensional view, and further, according to the design of the roller, the light diffusion plate can have a one-dimensional tine shape as shown in the third C; It is a side view of a light diffusing plate according to another preferred embodiment of the present invention; as shown in the figure ^ ^ '丨,' another preferred embodiment of the light diffusing plate, the front view is the same as the side view, / Is a two-dimensional zigzag shape; see also the fifth A and fifth 7 B pictures, where the fifth A picture is a front view, and the fifth b picture is a ~ 丄Another preferred embodiment of the invention The light diffusing plate has a shape of a jealous shape in the X direction and a shape in the Y direction. The main design of the γ direction is the extension of the return / line length. m bay angle

Example First, the optical grade PC raw material (Bayer 3301) is first processed by adding a light diffusing agent (S i 0 0), first using a pelletizing extruder, according to the weight percentage = adding 1% to 10% of si 1 ic 〇ne powder, mixed with PC rubber granules after quantitative addition, adding dispersants, plasticizers and other processing aids, fully extruded through an extruder, extruded into strip-shaped raw materials, and then cooled and pelletized through a water tank. Shaped PC material with ^ light diffusion function, after 70 ~ 90 ° C, fully dried for 3 ~ 6 hours, then at a processing temperature of 250 ~ 300C, a 2.0 mm light diffusion pc sheet is formed. Then through a roller Rolling, one-dimensional direction? It is 丨 m0 is 90 degrees. Therefore, in the trend of large-size development of the application field of liquid crystal displays, the requirements for the brightness and uniformity of backlight modules are becoming increasingly strict, in addition to the improvement of light sources The improvement of the optical original in the backlight module is also one of the methods to achieve this purpose. The present invention provides a method for manufacturing an optical structure of a high-brightness diffuser plate.

Page 10 200538810 V. Description of the invention (7) Roll rolling to compound the cymbals and diffuser plates together to reduce costs, reduce the difficulty of assembling backlight modules, and reduce the time required for assembly. It is stated that the present invention is a novel, progressive, and industrially usable person, and it should meet the patent application requirements stipulated by the Chinese Patent Law. No doubt, an application for an invention patent was filed in accordance with the law. Feeling prayed.

However, the above is only a preferred embodiment of the present invention, and is not intended to limit the scope of implementation of the present invention. For example, changes in shape, structure, characteristics, and spirit according to the scope of the patent application for the present invention are equivalent. Modifications should be included in the scope of patent application of the present invention.

Page 11 200538810 Brief description of the diagram The first diagram: a schematic diagram of the structure of a direct-type backlight module of the conventional technology, the second diagram: the manufacturing process of a light diffusion plate according to a preferred embodiment of the present invention FIG. 3A is a cross-sectional view of a light diffusion plate according to a preferred embodiment of the present invention, FIG. 3B is a side view of a light diffusion plate according to a preferred embodiment of the present invention; Figure A: This is a perspective view of a light diffusing plate according to a preferred embodiment of the present invention; Figure 3 is a side view of a light diffusing plate according to a preferred embodiment of the present invention; It is a side view of a light diffusing plate according to another preferred embodiment of the present invention; FIG. 5A is a side view of a light diffusing plate according to another preferred embodiment of the present invention; Figure: This is a top view of a light diffusion plate according to a preferred embodiment of the present invention. [Simplified description of drawing number] I 0 ’reflection sheet II’ plurality of light sources 1 2 ’light diffusion plate 13’ first prism sheet

Page 12 200538810 Brief description of the drawing 1 4 'Second diaphragm 1 5' Brightening film 1 Light diffusing plate 1 0 Optical resin 1 2 Light diffusing agent 1 4 texture 16 Ap angle p Distance between two ap angles Θ angle

Page 13

Claims (1)

200538810 VI. Scope of patent application1. A method for manufacturing a light diffusion plate of a direct type moonlight module, the main steps of which include: using an extruder to heat an optical resin and a light diffusing agent to perform the melting and mixing chain; And when a light diffusion plate is extruded and formed, a roller is used to roll at least one surface of the light diffusion plate, wherein the surface of the roller has a plurality of engravings. The manufacturing method of the light diffusion plate of the direct type backlight module described in item 1 of the scope of the patent application, wherein the optical resin is selected from the group consisting of polycarbonate, PMMA, MS, ABS, PET, PETG, PS, MBS And C0C. 3. The manufacturing method of the light diffusion plate of the direct type backlight module as described in item 1 of the scope of the patent application, wherein the light diffusing agent is selected from the group consisting of pMMA, MS, ABS, PS, PU, containing Si02, Mg ( (OH) 2, CaCO3, BaSO4, A12203, TiO powder. 4. · The manufacturing method of the light diffusion of the direct type backlight module described in item 1 of the patent application, wherein the light diffusion substrate further includes an antistatic agent, an ultraviolet absorber, a flame retardant, an antioxidant, and other processing aids. One of them or any combination thereof. 5. As described in the scope of the patent application, +, and π target map = manufacturing method of the light diffusion plate of the direct-type backlight module described in Pell, wherein the light miscellaneous η., ^ 卜 _ Nine expansion substrate The thickness is between 1mm and 10mm. 6 · As described in the first patent application scope ^ ^ 11 ^ # t ^ Light diffusion of the direct type backlight module described ^ Nine expansion board after the production is completed, it includes several rolls of top angle. 200538810 6. Scope of patent application 7. The method for manufacturing the light diffusion plate of the direct type backlight module described in item 6 of the scope of patent application, wherein the angle of the vertex angle is 80 to 110 degrees. 8. The manufacturing method of the light diffusion plate of the direct type backlight module as described in item 6 of the scope of the patent application, wherein the distance between the vertex angles is 5 ~ 2 0 0 // in. 9. The manufacturing method of the light diffusion plate of the direct type backlight module according to item 1 of the scope of the patent application, wherein the light diffusion plate is rolled into a one-dimensional zigzag shape after being rolled by the roller. 10. The method for manufacturing a light diffusion plate of a direct type backlight module as described in item 1 of the scope of the patent application, wherein the light diffusion plate is formed by two rollers to form equal staggered shapes in the two directions. 1 1. The manufacturing method of the light diffusion plate of the direct type backlight module according to item 1 of the scope of patent application, wherein the light diffusion plate is rolled by the roller to form a zigzag shape in the X direction and a difference in the Y direction Shape in X direction. 1 2. A method for manufacturing a direct-type backlight module light diffusion plate, which uses an extruder to heat an optical resin and a light diffusing agent to perform melting and mixing, and extrudes a light diffusion plate, wherein The light diffusion plate has a sawtooth shape in a two-dimensional direction. 1 3. A method of manufacturing a direct-type backlight module light diffusion plate, which uses an extruder to heat an optical resin and a light diffusing agent to perform f-melt mixing and extruding to form a light diffusion plate. The light diffusion plate has a tooth shape in the X direction and a shape different from the X direction in the Y direction. Page 15