CN1755450A - A method of manufacturing a light guide plate and an edge-lit backlight assembly - Google Patents

Abstract

A method of fabricating a light guide plate includes forming a rough surface on a mold plate using a laser, and fabricating the light guide plate using the mold plate so as to form the rough surface consisting of micro mirror structures on the light guide plate.

Description

A method of manufacturing a light guide plate and an edge-lit backlight assembly

technical field

The invention provides a method for manufacturing a light guide plate and the light guide plate, especially a method for manufacturing a light guide plate processed by laser and the light guide plate.

Background technique

Since the liquid crystal itself does not emit light, the backlight assembly is a key component of a liquid crystal display (LCD) panel. Its main function is to supply a light source with sufficient brightness and uniform distribution, so that the LCD panel can display images normally. As LCD panels have been widely used in many electronic products with growth potential, such as monitors, notebook computers, digital cameras, projectors, etc., the demand for backlight components and related components is also growing continuously.

Generally speaking, the backlight assembly can be divided into direct-type backlight assembly whose light source is directly below the display panel and edge-type backlight assembly whose light source is near the side of the display panel according to the location of the light source. Two designs. Wherein, since the edge-lit backlight assembly is provided with the light source generator on the side of the display panel, the size and manufacturing cost of the liquid crystal display can be reduced, and it can be applied to small electrical products.

Referring to FIG. 1 , FIG. 1 is a schematic diagram of a known edge-lit backlight assembly 10 . The side-light backlight assembly 10 mainly includes: a light guide plate (light guide plate, LGP) 14 arranged below the display panel 12; a plurality of lamp tubes 16 arranged on one side of the light guide plate 14, the plurality of lamp tubes can It is a cold cathode fluorescent lamp (cold cathode fluorescent lamp, CCFL); a lampshade 18 arranged on the outside of a plurality of lamp tubes 16; to reflect the light passing through the light guide plate 14 back to the light guide plate 14; an optical material layer 22 arranged between the light guide plate 14 and the display panel 12; and two lamp tube fixing parts 24, the two lamp tube fixing parts Installed on both sides of the lamp tube 16 for fixing the lamp tube 16 . Wherein, the lamp tube 16 is used to provide a light source to the display panel 12, the lampshade 18 and the reflector 20 are used to reflect the light generated by the lamp tube 16 into the light guide plate 14 to increase the utilization rate of light, so as to provide a Better light output. The micro-scattering points under the light guide plate 14 can destroy the total reflection of the light on the light guide plate 14 and refract the light out of the light guide plate 14 into the optical material layer 22. The optical material layer 22 can further atomize and focus the light refracted by the light guide plate 14. light to provide the light source required by the display panel 12.

It can be seen from the above that the light guide plate 14 is one of the key parts of the side-lit backlight assembly 10, and the function of the light guide plate 14 is to guide the scattering direction of light, to improve the luminance of the display panel 12, and to ensure the uniformity of the brightness of the display panel 12. Therefore, the design and manufacture of the light guide plate 14 is related to the optical design of the backlight assembly and the control of luminance and uniformity, and is the most important technology and cost of the backlight assembly manufacturer. Generally speaking, there are two methods for making the pattern of the known light guide plate 14 according to the manufacturing process. The first method is to use the method of screen printing. ” material, and print a circular or square pattern on the bottom surface of the light guide plate 14; the second way is to use a mold to directly form the light guide plate 14 with a pattern by injection molding. Referring to FIG. 2 , FIG. 2 is a schematic diagram of injection molding of a known light guide plate 14 . A sheet of metal 26 with a light guide plate pattern is first attached to a female mold (or mirror mold core) 28 of the injection molding mold, and then the molds are closed so that a male mold 30 and the female mold 28 are tightly combined. At this time, the raw material (usually propylene, commonly known as acrylic) is injected into a mold cavity 32 from the injection molding port of the male mold 30 along the direction of the arrow, and is combined with a replicating machine such as an injection molding machine and a heat press machine to The fabrication of the patterned light guide plate 14 is completed, and the pattern of the light guide plate 14 can be formed on the sheet metal 26 by sandblasting or etching.

However, in the known light guide plate manufacturing technology, since the mold for making the light guide plate is processed by sandblasting or etching to form a pattern with a fog surface or a dotted surface structure, the reproducibility of sandblasting and etching is not good, so it cannot be effective. Improve the reproducibility of mold making, which often causes the deviation of light distribution during mold making; in addition, in terms of controlling the density distribution of the light guide plate pattern, if you want to use the sandblasting surface to adjust the light guide plate pattern density with different roughness distribution The dense distribution, and then adjust the uniformity of the backlight assembly. Unfortunately, the current sandblasting technology cannot accurately control the density of processing points in different areas on the light guide plate. However, if only the entire surface can be made with the same roughness If the surface is sandblasted and matte, the uniformity of the light emitted by the backlight components is not easy to adjust. These are the bottlenecks faced by the production of light guide plates today.

Contents of the invention

An object of the present invention is to provide a light guide plate and a manufacturing method thereof to solve the above problems.

Another object of the present invention is to provide a structure of a light guide plate to improve the brightness of light at a normal viewing angle.

The invention discloses a method for making a light guide plate, which includes using a laser to make a rough surface on a template, and using the template to make the light guide plate to form a rough surface with a micro-mirror structure on the light guide plate.

The invention discloses a side-light backlight assembly, the side-light assembly includes a light source and a light guide plate, the light guide plate is installed on the side of the light source, includes a bottom surface and a light-emitting surface, the bottom surface is opposite to the light-emitting surface , and the bottom surface is a rough surface formed by laser processing.

Description of drawings

FIG. 1 is a schematic diagram of a known edge-lit backlight assembly.

FIG. 2 is a schematic diagram of injection molding of a conventional light guide plate.

FIG. 3 is a schematic diagram of an edge-lit backlight assembly of the present invention.

Fig. 4 is a side view of the structure of the light guide plate of the present invention.

FIG. 5 is a flow chart of the present invention for manufacturing a light guide plate.

FIG. 6 is a structural diagram of another light guide plate of the present invention.

Description of main component symbols:

50 edge-lit backlight components 52 display panels

54 light guide plate 56 light source

58 lampshades 60 reflectors

62 optical material layers 64 light tube fixing parts

66 light-transmitting plate body 68 light-emitting surface

70 bottom surface 72 prism structure

Detailed ways

Referring to FIG. 3 , the side-lit backlight assembly 50 of the present invention includes: a light guide plate 54 disposed below the display panel 52; a light source 56 disposed on one side of the light guide plate 54, which can be a plurality of cold-cathode fluorescent tubes a lampshade 58 located on the outside of the light source 56; a reflector 60 located below the light guide plate 54; an optical material layer 62 located between the light guide plate 54 and the display panel 52; and two lamp tube fixtures 64, The two lamp tube fixing parts 64 are installed on both sides of the light source 56 to fix the light source 56; wherein, the lampshade 58 and the reflector 60 are used to reflect the light generated by the light source 56 into the light guide plate 54, and the light guide plate 54 is It is used to scatter the light from the light source 56 to the optical material layer 62 , so as to provide the display panel 52 with uniform and higher brightness at the front viewing angle.

4, the light guide plate 54 of the present invention includes a light-transmitting plate body 66, which can be an acrylic plate. The light-transmitting plate body 66 includes a bottom surface 70 and a light-emitting surface 68, and the bottom surface 70 is opposite to the light-emitting surface 68. Below, and the bottom surface 70 is a rough surface; Referring to FIG. 5, the manufacturing method of the light guide plate 54 of the present invention includes the following steps:

Step 100: adjusting the processing parameters of a pulse laser;

Step 110: using the adjusted pulsed laser to make a surface of a template into a rough surface;

Step 120: use the template to make the light guide plate 54.

Continue to describe the steps of the above method in detail here. First, adjust the processing parameters of the pulsed laser, such as the intensity, frequency, and number of hits of the pulsed laser, to control the degree of depression and density of the laser hitting the surface of the template. The pulse laser can be a neodymium-yttrium aluminum garnet (Nd-YAG) laser, and then the surface of the template is struck by the pulse laser to form a rough surface. The template can be steel or acrylic material, etc., and the pulse laser The principle of processing is to use the energy of the pulsed laser to melt the surface of the template, and because of the cohesive force of the template material itself and its surface tension, a micro-mirror structure will be generated where the laser hits. Next, the template can be used as a mold core, and the template can be used for injection molding or thermocompression molding to produce the light guide plate 54, and the bottom surface 70 of the light guide plate 54 corresponds to the shape of the template produced by the impact of the laser beam. rough surface; or use the template for electroforming overmolding to form a overmolding template, and then use the overmolding template as a mold core, and use the overmolding template for injection molding or thermocompression molding to make the light guide plate 54, At this time, the structure of the surface of the light guide plate 54 is the same as the structure of the template after being struck by the laser beam.

Compared with the known manufacturing method of the light guide plate, the method for forming the bottom surface structure of the light guide plate of the present invention is to use the pulse laser processing technology to make the mold of the light guide plate, so that the bottom surface of the light guide plate has a rough surface with a micro-mirror structure, thereby greatly improving the light guide plate. In addition, due to the high precision of laser processing of the mold, it is possible to control the distribution of light guide plate patterns by adjusting the laser processing parameters, and then control the uniformity of light emission of the backlight component. , so the reproducibility of the mold is good, which means that the repeatability of mold making can be improved. To sum up, the present invention can effectively increase the luminous efficiency and quality of the light guide plate and reduce the production cost of the light guide plate, thereby helping to improve market competitiveness and product profit.

Since the bottom surface 70 of the light guide plate 54 of the present invention is a rough surface with a micro-mirror structure, the reflection efficiency of light can be improved through the micro-mirror structure, thereby achieving the effect of improving brightness. In addition, the rough surface formed by laser processing in the present invention can be used not only as the bottom surface of the light guide plate, but also as the light emitting surface of the light guide plate.

In addition, as shown in FIG. 6 , the light-emitting surface 68 of the light guide plate 54 can be composed of linear prism structures 72 arranged side by side. After the light enters the light guide plate 54, it passes through the rough surface of the bottom surface 70 to generate diffusion, and then passes through the prisms. The structure 72 produces refraction or reflection, so that the angle of light is concentrated to the front (ie, viewing angle range), so as to improve the brightness of the front viewing angle.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the claims of the present invention shall fall within the scope of the patent of the present invention.

Claims (11)

1. A method for making a light guide plate, comprising: (a) striking a surface of a template with a laser to form a rough surface; and (b) Using the template to make the light guide plate. 2. The method of claim 1, wherein a NdYAG laser is used in step (a). 3. The method of claim 1, wherein the laser in step (a) is a pulsed laser. 4. The method of claim 1, further comprising adjusting laser processing parameters to control the roughness of the rough surface. 5. The method of claim 1, wherein the rough surface is composed of a micro-mirror structure. 6. The method as claimed in claim 1, wherein in step (b), the template is used for injection molding to produce the light guide plate. 7. The method according to claim 1, characterized in that: in the step (b), the light guide plate is made by using the template by thermocompression molding. 8 . The method according to claim 1 , wherein in step (b), the template is used for electroforming overmolding to form a overmolding template, and then the light guide plate is manufactured using the overmolding template. 9. An edge-lit backlight assembly, comprising: a light source; and A light guide plate, which is installed on the side of the light source, includes a bottom surface and a light-emitting surface, the bottom surface is relatively arranged below the light-emitting surface, and the bottom surface is a rough surface composed of micro-mirror structures. 10. The edge-lit backlight assembly according to claim 9, wherein the light emitting surface is composed of linear prism structures arranged side by side. 11. An edge-lit backlight assembly, comprising: a light source; and A light guide plate, which is installed on the side of the light source, includes a bottom surface and a light-emitting surface, the bottom surface is relatively arranged below the light-emitting surface, and the light-emitting surface is a rough surface composed of micro-mirror structures.

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