TW442691B - Surface light source device of integrated light guide plate and prism sheet - Google Patents

Abstract

The present invention provides a novel structure of a surface light device using for a liquid crystal display. The structure comprises prism sheets, a light guide plate with a plurality of micro-diffusion-lens, a reflector, an incident light source and a lamp reflector. Also provides are two methods of forming a mold of the light guide plate of the present invention. The first method directly forms inserts on a substrate using thermoplastic resins, then transforms the inserts into a mold by electro-forming. The second method directly forms a mold of the light guide plate of the present invention by using a multi-electrode array to electrochemically etch a metal substrate. In both methods, the light guide plate is formed by injecting or hot pressing with the molds. The backside of the light guide plate formed with the methods of the present invention possesses dense and small optical structure, has a high degree of brilliance and uniformity, does not require a diffuser and can be produced by simple processes. Moreover, the present invention provides a prism sheet integrated into a light guide plate to form a complex light guide plate, wherein an array-micro-lens is formed on the surface of the light guide plate. The method of forming the complex light guide plate is the same as the light guide.

Description

442691 V. Description of the invention (l) 4 Field of the invention: The present invention relates to a new type of rear surface light source structure 'especially related to a kind of-it is not necessary to use a diffuser film and integrate a piece of diamond lens to the light guide plate' and can make the surface light source out Surface light source structure with more uniform light and higher brightness. : Known technology: Backlight module refers to a component that can provide a surf ace 1 ight source of the product. It is currently used in various information, communication and consumer products, such as LCD (L i qu id Crystal Display (LCD), film scanner, slide viewing box and other products. However, in recent years, 3C products have developed in the direction of lightness, thinness, shortness, smallness, and low power consumption. Therefore, in the future, backlight modules are considering market requirements for light weight, thinness, low power consumption, high brightness, and cost reduction. Maintaining the competitiveness in the future market, developing and designing new backlight modules and new manufacturing technologies for injection molding are the directions and important issues for future efforts. Focusing on this, the present invention proposes a new design and manufacturing method of the light guide plate in the backlight module. The structure of the backlight module, as shown in FIG. 1, mainly includes an incident light source 3 (light emitting diode or cold cathode tube, etc.), a light guide plate 1 (Reflector), a lamp reflector ( Lamp Ref lector) and outer frame combination 2, diffuser 4 (Diffuser), prism sheet 5 (Prism Sheet) ^ In the figure, the light source 3 directly or indirectly reflects through the lamp reflector 2 and enters the light guide plate 1, and propagates through the light guide plate. After the optical structure design surface and the reflection plate 2 destroy the total reflection phenomenon, the light source is diffused and emitted from the front of the light guide plate 1 at an angle, and is evenly distributed in the light-emitting area.

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V. Description of the invention (2) Adjust the viewing angle of the light source by the diffuser 4 and the prism lens 5 so that the light can be concentrated in the viewing angle selection of the liquid crystal display ', to meet the optical characteristics requirements of the liquid crystal display. --- The performance of the light from the traditional light guide plate in brightness and uniformity is poor. For example, the patent of the Republic of China 86, 1 04, 842 is printed on a soft screen with a material containing a high divergence light source. The nature of the printed material's absorption and re-diffusion of the light source releases and breaks the internal propagation caused by the total reflection effect. And evenly distributed in the light-emitting area, but because the dot particles are not fine enough, it will make the light uniformity is not good, and it is not one-time molding and processing takes time. In addition, the Republic of China Patent 84,206,661 and the U.S. Patent 1 ^ 5887964 K will inject some transparent particulate materials with injection directly into the light guide plate during injection molding, and use the difference in concentration to make the source evenly distributed in the light guide area of the light guide plate. Due to the large particles of the scattering material, the difficulty in controlling the density, and the large energy loss of light in the light guide plate, the uniformity and brightness of the light from the light guide plate are not good. The Republic of China Patent 85, 21 6,575 proposes to use precision machining, laser engraving or etching to create intermittent linear patterns on the back of the light guide plate that are perpendicular to the direction of light travel to destroy total reflection. However, consider the accuracy of the machine, its processing accuracy and The optical design is still inferior to the light homogeneity and brightness of the concept proposed by the present invention. Based on the above analysis, 'if the optical structure on the back of the light guide plate is denser and smaller, the uniformity and brightness of the extracted light will be higher, and it is unnecessary to use a "diffusion film", and the thickness and power consumption of the backlight module can be reduced. Here, the present invention proposes a light guide plate with " micro-diffusion-lens "

Page 7 44269 ti V. Description of the invention (3) ------- _ (Ught gUlde PUte) will effectively solve these problems. In the future, if a piece of diamond lens is combined to form a light-guiding pole, the composite guide will be accessible in the future, and the number of parts of the backlight module will be reduced, and the engineering process will be reduced. Summary of the Invention: The present invention proposes a liquid crystal The new design of the surface light device structure for the display. The structure includes two interlaced lenses, "micro-diffused lenses", light guide plates, reflective plates, and incident light sources (cold-electrode or light-emitting diode). And lamp reflection leather. The incident light source introduces light into the light guide plate, and the bottom surface of the light guide plate forms a micro-diffused lens. The density of the micro-diffused lens distribution increases as the distance from the light source increases. The light is taken out from the front of the light guide plate, and then the light collecting action of the prism lens can obtain high-intensity uniform light. The invention provides a light guide pUte master mold forming method with micro-diffusion-lens and a surface light source structure having the light guide plate. The surface light source structure does not need to use a diffusion film and can The area light source emits more uniform light and higher brightness. The invention forms a micro-level and high-density "micro-diffusion-lens" array on the back of the light guide plate, so that the light emitted by the light guide plate is more uniform and higher in brightness. The micro-diffuse lens master mold will be directly molded on the substrate with a thermoplastic resin to form an electroformed mold core, and then electroformed into a light guide plate.

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The master mold, and then the light guide plate is formed by injection or hot pressing. — In the present invention, a photoresist structure is formed on a substrate (such as a mirror stainless steel, conductive glass or silicon substrate), and then a thermoplastic resin (thermoplastic plastic) is filled thereon to remove the photoresist, and the thermoplastic resin is deformed by heating. Micro_. Diffusion lens master. The invention proposes a light-transmitting plate mother transverse molding method with micro-diffusion lenses, and the micro-diffusion lens pitch can reach several micrometers or even smaller. If the quality requirements of the light guide plate light source are relatively low, the present invention also proposes to form a photoresist structure directly on the substrate. Then, the photoresist can be directly heated to form a micro-diffusive lens master mold, and then electroformed and turned. Another method for forming a light guide plate master with " micro-diffuse lens " is to use a flat electrode with an array micro-photoresist structure (Flat Electrode) electrochemical micromachining (Electrchemieal

Micro-Machining (EMM) metal substrate forming light guide plate master mold "First provide a plate electrode with array micro-resistance structure, and then electroformed nickel or composite electroformed nickel alloy on a substrate. Then, the plate electrode and the substrate were energized and subjected to electrochemical fine etching to form a light guide plate master having a micro-diffused lens. Finally, the light guide plate is formed by injection or hot pressing through the light guide plate master mold. Another method for forming the light guide plate master mold with the "micro-diffusive lens" of the present invention is to form a light guide plate master mold by using an array microelectrode (Multi-Electrode Array) electrochemical micromachining metal substrate. An array of microelectrodes is provided first, and then, an electroformed or composite alloy is electroformed on a substrate. Then, the array microelectrodes and the substrate are energized and electrochemically finely etched to form a light guide plate master with a micro-diffused lens. Finally, the light guide plate master mold is used for injection or hot pressing to form the light guide plate 8 mm Hi. In 4269 1 V. Description of the invention (5) This patent proposes another invention is to integrate a diamond lens into the light guide plate to form a "composite light guide plate" ". Its structure includes a diamond lens (one piece), a composite light guide plate, a reflective plate, an incident light source (cold-cathode tube, light-emitting diode), and a lamp reflector. The incident light source introduces light into the light guide plate, and the bottom surface of the light guide plate forms a micro- · diffusion lens array. The distribution of the micro diffusion lens increases as the distance from the light source increases. 'The micro diffusion lens on the bottom surface of the light guide plate and the upper surface etc. The pitch array type micro-condensing lens, the lamp tube reflector and the reflecting plate enable light to lead out uniform and high-brightness light from the front face of the light guide plate, and then the light with uniform brightness can be obtained through the light collecting effect of the diamond lens. The mother mold forming method of the composite light guide plate of the present invention is as described above. The lower mold is a " micro-diffusion-lens " mother mold; the upper mold is a " microarray-type condenser lens " mother mold. The molding method is as described above, that is, a micro-condensing lens array with an equal pitch and a small diameter is formed on the substrate, and then combined with the upper and lower molds to form a "composite light guide plate". The composite light guide plate surface light source element proposed by this design The new design will halve the use of diamond lenses, eliminate the need for a diffuser film and reduce the manufacturing process, and at the same time, the light utilization efficiency will be relatively improved. Brightness and uniformity of the diagram are also briefly explained. Figure 1 shows the backlight module The structure is shown in circles. Figures 2A to 2F are side views (fine patterns) of the light guide plate master mold forming method of the present invention having "micro-diffusive lenses". The circles 3A to 3C show the present invention has "micro-diffusion" Lens, another way to form the light guide plate master

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AA269 II V. Description of the invention (6) Figures 4A to 4B are side views showing another method for forming a light guide plate with a "micro-diffused lens" according to the present invention. FIGS. 5A to 5B are side views showing another method for forming a light guide plate master mold having a “micro-diffusive lens, 1” of the present invention. FIG. 6 is a diagram showing the surface of the light guide plate having a “micro-diffusive lens” according to the present invention. Element structure diagram. Figure 7 is a schematic diagram showing the structure of a surface light source of a composite light guide plate of the present invention. Explanation of symbols: 1 to light guide plate; 2 to outer frame combination; 3 to incident light source; 4 diffuser plate; 5 to diamond lens, 6, 16, 34, 44 to substrate shielding layer, 17 to thermoplastic resin layer; 9, 1 9 ~ Micro-diffused lens pitch; 1 〇 '20-Electric scale mold core '; Π, 21, 38, 48 ~ Light guide plate mother mode; FE ~ flat electrode; 30 ~ flat plate; 32 ~ thick mode photoresistance, 36, 46 ~ metal layer; MEA ~ array microelectrode; 40 ~ side wall of array microelectrode; 42 ~ endpoint of electrode; 51, 52 ~ rhombic lens. 53 ~ light guide plate; 54, 64 ~ reflecting plate; 55, 65 ~ Incident light source; 56, 66 ~ lamp reflector; 63 composite light guide plate. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, some preferred embodiments are given below, and the accompanying drawings are described in detail below. Preferred Embodiment Example 1:

Λ42 69 Ί 5. Description of the invention (7) FIG. 2 is a side view (fine pattern) of a light guide plate master mold forming method with a 12 micro-diffusive lens " according to the present invention. First, refer to FIG. 2A to form a shielding layer 8 on the substrate 6, for example, spin coating ... 12 / ζιη thick i-ray positive photoresist layer 8, wherein the material of the substrate 6 may be mirror wood. Rust steel , Silicon wafer or conductive glass, but there are no certain restrictions. After that, an exposure and development process is performed to form a micro-photoresist structure with an opening 9. The diameter of the opening 9 can be larger in the distance from the light source, and smaller or farther away from the light source according to the optical design. , The farther is larger). However, after the negative photoresist 1 is exposed, the developing solution will invade (Penetrate) the chain during the development. The negative photoresist molecule will cause the negative photoresist to swell (Swel 1 ing), resulting in negative photoresist after development. The error between the case and the case on the reticle increases, so when the process requirements; less than 3 yra or less, the use of negative photoresist is quite inappropriate. Therefore, in the embodiments of the present invention, a positive photoresist is currently used, but there is no limit. Secondly, please refer to FIG. 2B, apply the thermoplastic resin 7 to the photoresist 8 with a thickness of about 15 μm, and remove the extra resin to expose the photoresist layer 8, as shown in FIG. In order to prevent the photoresist layer 8 from being removed at the same time, the thermoplastic resin 7 may use a negative photoresist having the same photosensitive wavelength as the photoresist 8 and perform maskless exposure before the photoresist layer 8 is removed. Then refer to FIG. 2]) to remove the photoresist layer 8. Furthermore, please refer to FIG. 2E, heat the thermoplastic wax 7 to form the desired light guide plate electroforming mold core 1 0 according to the physical characteristics of the surface tension of the tree and the grease. »Then, refer to Fig. 2f 'Electroforms this mold core to form a light guide plate master mold n with a micro-diffused lens. Finally, the light guide 1 2 page 12 V. Description of the invention (8) The plate master 11 adopts injection or hot pressing process to form a light guide plate (not shown) a. The process technology proposed by the present invention, its micro-diffused lens The distance 9 can reach several micrometers or even smaller, and the density of the micro-diffusion lens 10 can be designed to be closer to the light source, and closer to the light source. 'This will make the extraction of light more uniform, and the degree of brightness-- High β, because the micro-diffusion lens is quite dense and small, it will not be necessary to use a diffusion film. _ Embodiment 2: FIG. 3 is a side view of another method for forming a light guide master with a “micro-diffused lens” according to the present invention. If the "micro-diffusive lens" distance of 19 is not required to be less than 3 μm, the photoresist with a honeycomb resin can be used first. For example, Shipley TF-20 is used to coat the substrate 16 and then, Then, exposure, development, and baking processes are performed to form a micro photoresist structure, as shown in FIG. 3A. Secondly, please refer to circle 3B, heat the thermoplastic resin 17 to form the desired light guide plate electroforming mold core 20 with "micro-diffusive lens" according to the physical characteristics of the surface tension of the resin. For example, heat Shipiey TF-20 at 140t for 15min . Then, referring to FIG. 3C, this mold core 20 is electroformed to form a light guide plate master mold 21 having a micro diffusion lens. Finally, the light guide plate master mold 21 can be formed by an injection or thermal process to form a light guide plate (not shown). As mentioned above, the density of the "micro diffuse lens" at the bottom of the light guide plate can be designed to be closer to the light source and closer to the light source. This will make the light more uniform and the brightness More stingy. Example 3: Λ42691 Five 'invention description (9) Figure 4 is a guide with " micro-diffusion lens " according to the present invention. Another side view of the forming method of the light plate master mold is a process of electrochemical microfabrication Flat Electrode to form a light guide plate master mold, please refer to Figure 4A first to provide a flat electrode FE, such as coating a thick mold photoresist 32 on a platinum or ballast plate. 30, and forming a plate by exposure and development The electrode, in which the thick-mode photoresistance distribution is designed according to the optical structure of the light guide plate. After that, a metal layer 36 is formed on a plate 34, for example, electroformed nickel or composite electroformed recording gold is used. It can be mirror stainless steel, silicon wafer, glass, etc. Then, please refer to Section 4B 囷 'to energize the plate electrode FE and the substrate 34-electrochemical micro-etching to form a light guide plate master mold 38 with micro-diffused lenses. Finally, The light guide plate mother mold 38 can be used to form a light guide plate (not shown) by injection or hot pressing. Embodiment 4: The fifth unit is a light guide plate mother with "micro-diffused lens" according to the present invention. Die another The side view of the forming process is the use of electrochemical micro-processing of Array microelectrodes (Multi-Electrode Array) to form a light guide plate master mold. 'First refer to Figure 5A' to provide an array microelectrode mea. The side wall 40 of the array microelectrode is After insulation treatment, the geometric shape of the terminal end 42 of the electrode is pointed. Thereafter, a metal layer 46 is formed on a substrate 44, for example, electroformed nickel or a composite electroformed nickel alloy is used. The substrate 44 may be made of a mirror. Stainless steel, silicon wafer, glass, etc. Then, referring to FIG. 5B, the array microelectrode MEA and the substrate 44 are electrified for electrochemical micro-etching to form a light guide plate master mold 48 having a micro-diffused lens. Finally, by using Light Guide Board Chess

Page 14 "269 1 V. Description of the invention (48) 48 'uses an injection or hot pressing process to form a light guide plate (not shown). In this embodiment, because the electrode sidewall is insulated and the geometry of the electrode tip is changed, the guide The optical microstructure on the light plate master mold is denser and smaller, so that the brightness is higher.-Example 5: 'Figure 6 is a light guide-plate mother mold warp with " micro-diffusive lens, according to the present invention. The surface light device structure assembled by heat pressing or emitting the light guide plate formed by the manufacturing process is round. This structure has two interlaced diamond lenses 51 and 52, a light guide plate 53 of a "micro diffusion lens", and a reflection plate 54. Incident light source (cold-cathode tube, light-emitting diode) 55 and lamp reflector 56. In this design, because the micro-diffused lenses on the bottom surface of the light guide plate are densely distributed and small, the light from the light guide plate is more uniform, so it is unnecessary A diffusion film is used. Example 6: Figure 7 is a structural diagram of a "composite light guide plate" surface light source element proposed according to the present invention. The bottom surface of this composite light guide plate 63 is a micro-diffused lens and the upper surface is a descending type Micro Concentrating The mold is formed as described above, that is, the lower mold is a micro-diffused lens mold, and the upper mold is an array type micro-condensing lens. When the incident light source 65 directly enters a composite light guide plate, or the lamp tube reflection cover 66 and the reflection plate 64 Reflecting into the light guide plate "The uniform light from the micro diffuser lens array on the bottom surface of the light guide plate and the micro-condensing lens array on the top surface make the light from the light guide plate more uniform and brighter. The light from the light guide plate is then borrowed A piece of diamond lens 61 gathers light and adjusts the viewing angle β. The new design proposed by the present invention

4 42 69 \ V. Description of the invention (π) The cost of materials will be reduced because the use of diamond lenses is halved and the use of a diffuser film is not necessary; the production process is simplified, the production cost is low and the yield is high; the more important is the surface light source The emitted light is more uniform and has higher brightness. Although the present invention has been disclosed as above with several preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

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Claims (1)

Providing a substrate; forming a shielding layer on the substrate; forming the shielding layer with a plurality of openings; 6. Scope of patent application: The shielding layer is heated to form an electroformed mold core; and the mold core is electroformed to form a light guide plate master mold having a micro-diffused lens. 7. The method according to item 6 in the scope of patent application, wherein the substrate is mirror stainless steel, silicon wafer or conductive glass < s 8. The method according to item 6 in the scope of patent application, wherein the shielding layer is It is a thermoplastic resin. * ^ 9. The method as described in item 6 of the scope of patent application, further comprising forming a light guide plate master mold with micro-diffused lenses, and then performing an injection or hot pressing process to form the light guide plate. '10. A method for forming a master mold with a composite light guide plate, including the following steps: providing a flat electrode; providing a substrate; forming a metal layer on the substrate; and electrifying the flat electrode and the substrate for electrochemical microfabrication Etching to form a light guide plate master with micro-diffusion penetration. π. The method as described in item 10 of the scope of the patent application, wherein the flat plate is formed by coating a thick mold photoresist on a flat plate or a thin plate through exposure and development. 12. The method according to item 10 of the scope of patent application, wherein the substrate is a mirror stainless steel, a silicon wafer or a conductive glass. Λ 13. The method according to item 10 of the scope of patent application, wherein the metal layer is formed on the substrate by electroforming nickel or a composite electroforming nickel alloy. " 土 14. A method for forming a master mold with a composite light guide plate, " includes the following BΗI, page 18, 44269 1 VI. Patent application steps: Provide an array of microelectrodes; provide a substrate; and form a metal on the substrate Layer; and electrifying the array microelectrode and the substrate for electrochemical micro-etching to form a light guide plate master with a micro-diffused lens. 1 5 · The method as described in item 14 of the scope of patent application, wherein the side wall of the array microelectrode is insulated, and the geometry of the end point of the electrode is pointed. 16. If item 14 of the scope of patent application In the method, the substrate is a mirror stainless steel, a silicon wafer, or a conductive glass. 17. The method according to item 14 of the scope of patent application, wherein the metal layer is formed on the substrate by electroforming nickel or a composite electroforming nickel alloy. 18. A surface light source structure with a composite light guide plate, comprising: a reflective plate: a light guide plate with a micro-diffused lens, which is located on the reflective plate; an incident light source, which is located on one side of the light guide plate; An incident light source reflecting cover is located on one side of the incident light source; a first diamond lens is located on the light guide plate; and a second diamond lens is located on the first diamond lens and is in contact with the first A pair of diamond lenses are interlaced. Right: 19. The structure described in item 18 of the scope of patent application ′ Υ Λ, and the light guide plate of the square micro-diffused lens is especially manufactured according to item 1, 6, 10 or 14. Page 19