JP2009158403A - Light guide plate with laser-processed pattern formed on incident surface, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light guide plate with laser-processed patterns formed on an incident surface; and its manufacturing method. <P>SOLUTION: This method includes steps of: (a) irradiating a template with a laser beam to form a plurality of holes on its surface; and (b)manufacturing a light guide plate with the template to form a plurality of laser-processed patterns on an incident surface of the light guide plate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light guide plate and a manufacturing method thereof, and more particularly to a light guide plate having a laser processing pattern on an incident surface and a manufacturing method thereof.

  A liquid crystal panel requires a backlight module because the liquid crystal itself does not emit light. The backlight module provides a light source with favorable brightness and uniformity, and allows an image to be displayed on a liquid crystal panel. As the range of use of liquid crystal panels in monitors, notebook computers, digital cameras, and projectors expands, the demand for backlight modules and related devices is increasing.

  The backlight module is classified into a direct type (providing a light source directly below the panel) and an edge light type (providing a light source on the outer edge of the panel) depending on the position of the light source. Among them, since the light source generator is provided on the outer edge of the display panel, the edge light type backlight module is useful for downsizing the liquid crystal display and reducing the manufacturing cost, and is suitable for small electronic products.

  Please refer to FIG. FIG. 1 is an explanatory view showing a conventional edge light type backlight module 10. The edge light type backlight module 10 provided under the display panel 12 includes a light guide plate (LGP) 14 provided under the display panel 12 and a plurality of light sources 16 (for example, provided on one side of the light guide plate 14). A light emitting diode (LED)), a cover 18 provided outside the plurality of light sources 16, a reflector 20 provided below the light guide plate 14 and reflecting the light transmitted through the light guide plate 14 to the light guide plate 14. An optical material layer 22 provided between the light guide plate 14 and the display panel 12 is included. Among them, the light source 16 supplies light to the display panel 12, and the cover 18 and the reflection plate 20 reflect the light from the light source 16 to the light guide plate 14, thereby increasing the usage rate of light and optimizing the luminance output. The scattering point below the light guide plate 14 destroys the total reflection of the light guide plate 14, refracts light, and guides it to the optical material layer 22 outside the light guide plate 14. The optical material layer 22 atomizes and converges the light from the light guide plate 14 and irradiates the display panel 12 with uniform and high luminance light.

  As described above, the light guide plate 14 is a core element indispensable for the edge light type backlight module 10, and adjusts the light scattering direction to increase the luminance of the display panel 12 and to improve the luminance uniformity of the display panel 12. Has a function to secure. Since the light guide plate 14 affects the optical design, brightness, and uniformity of the backlight module, it is important in manufacturing the module. There are two types of manufacturing methods for the pattern of the light guide plate 14. First, the light guide plate 14 is manufactured by printing a circular or square pattern by a screen printing method on the bottom surface of an acrylic flat plate provided with a material having high reflectivity and no light absorption. The second is a mold that forms a pattern on the incident surface or the exit surface of the light guide plate 14. Please refer to FIG. FIG. 2 is an explanatory view showing the injection molding of the conventional light guide plate 14. First, a metal thin film 24 having a light guide plate pattern is attached to a female mold (or mirror insert) 26, the male mold 28 and the female mold 26 are brought into close contact, and the raw material (acrylic) is molded from the injection port of the male mold 28 along the arrow method. The light guide plate 14 having a pattern is manufactured by injection into the holes 30 and using an injection device / hot pressure device. The pattern of the light guide plate 14 is formed on the metal thin film 24 by a processing technique such as a cutting tool, a lathe, wire cutting, etching, or sandblasting.

  As described above, the conventional technique produces a light guide plate pattern with a sand blower or a bite. However, the method using a byte has disadvantages such as high cost, long time required, low definition, and difficulty in producing diverse patterns. In addition, regarding the density distribution control of the light guide plate pattern, it is ideal to adjust the density distribution of the light guide plate pattern and the light emission uniformity of the backlight module by adjusting the roughness of the target surface with a sandblaster. Unfortunately, with the current sandblasting technology, it is impossible to make the roughness different for each region of the light guide plate, and even if a surface with uniform roughness can be made, the uniformity of light emission cannot be easily adjusted.

  The above is a problem in manufacturing the light guide plate.

  In order to solve the above-described conventional problems, it is an object of the present invention to provide a light guide plate having a laser processing pattern on an incident surface and a manufacturing method thereof.

  The present invention provides a method of fabricating a light guide plate. The method includes: (a) irradiating a template with a laser to form a plurality of holes on the surface; and (b) producing a light guide plate with the template and processing a plurality of lasers on the incident surface of the light guide plate. Forming a pattern.

  The present invention further provides an edge light type backlight module. The backlight module includes a light source and a light guide plate provided on a side surface of the light source. The light guide plate includes an incident surface that guides light from the light source into the light guide plate and has a laser processing pattern, and an output surface that guides light that enters the light guide plate from the light source.

  The light guide plate pattern manufacturing method according to the present invention uses a laser processing technique to manufacture a light guide plate mold and a laser processing pattern on the light incident surface of the light guide plate, thus greatly improving luminous efficiency and shortening the manufacturing time. The cost can be reduced and various high-precision patterns can be produced. In addition, laser processing can eliminate the problem of wear of the bite and shorten the light mixing distance of the light guide plate, and the laser processed mold has high precision and good reproducibility. Therefore, the present invention has an effect of improving the light emission efficiency of the light guide plate and reducing the manufacturing cost.

  In order to elaborate on the features of such an apparatus and method, specific examples are given and described below with reference to the figures.

  Please refer to FIG. FIG. 3 is an explanatory view showing an edge light type backlight module 50 according to the present invention. As shown in FIG. 3, the edge light type backlight module 50 provided under the display panel 52 is provided on one side of the light guide plate (LGP) 54 provided under the display panel 52 and the light guide plate 54. A plurality of light sources 56 (for example, LEDs), a cover 58 provided outside the plurality of light sources 56, a reflection plate 60 provided under the light guide plate 54, and provided between the light guide plate 54 and the display panel 52. Optical material layer 62 formed. Among them, the light source 56 generates light and applies it to the display panel 52, and the cover 58 and the reflection plate 60 reflect the light from the light source 56 to the light guide plate 54 to increase the usage rate of light and optimize the luminance output. The light guide plate 54 is, for example, an acrylic plate, and scatters light from the light source 56 and strikes the optical material layer 62. The optical material layer 62 includes, for example, an optical material such as a prism, atomizes and converges light from the light guide plate 54, and applies uniform and high-intensity light to the display panel 52.

  Please refer to FIG. 3 to FIG. 4 is an external view of the light guide plate 54 according to the present invention, and FIG. 5 is a side view of the structure of the light guide plate 54 according to the present invention. The light guide plate 54 includes an incident surface 64 that guides light from the light source 56 into the light guide plate 54, and an output surface 66 that guides light that has entered the light guide plate 54 to the optical material layer 62 above the light guide plate 54. The optical material layer 62 atomizes and converges the light from the light guide plate 54, and applies uniform and high luminance light to the display panel 52. A plurality of laser processing patterns 68 are formed on the incident surface 64 and the output surface 66 of the light guide plate 54. The laser processing patterns 68 are volcanic or spherical and are arranged in a linear or array form. The plurality of laser processing patterns 68 formed on the emission surface 66 scatter light uniformly and strike the optical material layer 62, and the installation thereof is arbitrary. The plurality of laser processing patterns 68 formed on the incident surface 64 improve the uniformity of incident luminance of the light guide plate 54, reduce the occurrence of the light arc phenomenon, improve the light mixing effect of the LED light source 56, and increase the light mixing distance. Effectively shorten.

Please refer to FIG. FIG. 6 is a flowchart of a method for manufacturing the light guide plate 54 according to the present invention.

Step 100: Adjust laser processing parameters.

  Step 102: Form a plurality of holes on the surface of the template with the adjusted laser.

  Step 104: The light guide plate 54 is manufactured using the above template, and a plurality of laser processing patterns are formed on the incident surface 64 of the light guide plate 54.

  More specifically, first, processing parameters such as laser intensity, frequency, and the number of irradiations are adjusted to control the degree of dents and the degree of density of the holes formed on the template. The laser used here is a pulse laser such as a neodymium yag (Nd-YAG) laser. Next, a plurality of holes are formed in the template with a laser. The template used here is steel such as SUS or STAVAX or acrylic. When a laser is applied to the template, a spherical recess is formed on the surface of the template due to cohesive force and surface tension. Thereafter, the light guide plate 54 is manufactured by an injection molding method or a hot pressure method using the template as an insert. If it does so, the laser processing pattern 68 of the light-guide plate 54 will correspond to the dent of a template.

  The laser processing pattern of the incident surface 64 of the light guide plate 54 can be a polka dot pattern. Please refer to FIG. 7 to FIG. 7 to 9 show several types of laser processing patterns 68 according to the present invention. The laser processing patterns 68 are regularly or irregularly arranged according to design requirements. If the laser processing pattern 68 is provided at the incident position between the LED light sources 56 on the incident surface 64 of the light guide plate 54 and the light from the light source 56 is scattered inside the light guide plate 54, the light mixing distance of the LED light source 56 is shortened. Thus, the dark spot appearing between the light sources 56 can be eliminated and the dark spot problem of the edge light type backlight module 50 can be solved. At the same time, if the light emission effect of the LED light source 56 and the matching LED light source 56 are effectively used, the amount of the LED light source 56 used can be reduced and the cost can be reduced. Such brightness adjustment can increase the light output efficiency of the light guide plate 54 and expand the visible range of the display panel 52.

  The above are preferred embodiments of the present invention, and do not limit the scope of the present invention. Accordingly, any modifications or changes that can be made by those skilled in the art, which are made within the spirit of the present invention and have an equivalent effect on the present invention, shall belong to the scope of the claims of the present invention. To do.

  The present invention includes the use of laser processing for pattern production of the light guide plate, and can be implemented.

It is explanatory drawing showing the conventional edge light type backlight module. It is explanatory drawing showing the injection molding of the conventional light-guide plate. It is explanatory drawing showing the edge light type backlight module by this invention. It is an external view of the light-guide plate by this invention. It is a side view of the light-guide plate structure by this invention. 3 is a flowchart of a method for manufacturing a light guide plate according to the present invention. It is 1st explanatory drawing showing the laser processing pattern by this invention. It is the 2nd explanatory view showing the laser processing pattern by the present invention. It is a 3rd explanatory drawing showing the laser processing pattern by this invention.

Explanation of symbols

10, 50 Edge light type backlight module 12, 52 Display panel 14, 54 Light guide plate 16, 56 Light source 18, 58 Cover 20, 60 Reflector 22, 62 Optical material layer 24 Metal thin film 26 Female type 28 Male type 30 Type hole 62 Optical material layer 64 Entrance surface 66 Output surface 68 Laser processing pattern

Claims (12)

A method of manufacturing a light guide plate,
(A) irradiating the template with a laser to form a plurality of holes in the surface;
(B) producing a light guide plate with the above-mentioned template, and forming a plurality of laser processing patterns on an incident surface of the light guide plate.   2. The method of manufacturing a light guide plate according to claim 1, further comprising the step of adjusting a laser processing parameter to control a degree of density of the plurality of holes formed in the template.   2. The light guide plate manufacturing method according to claim 1, further comprising the step of adjusting a laser processing parameter and controlling a degree of depression of a plurality of holes formed in the template.   2. The method of manufacturing a light guide plate according to claim 1, wherein the step (b) includes manufacturing the light guide plate by an injection molding method using the template.   2. The method of manufacturing a light guide plate according to claim 1, wherein the step (b) includes manufacturing the light guide plate by a hot pressing method using the template. An edge light type backlight module,
A light source;
A light guide plate provided on a side surface of the light source,
The light from the light source is guided into the light guide plate, the incident surface having a laser processing pattern,
A backlight module comprising: an exit surface that guides light entering the light guide plate from the light source.   The backlight module according to claim 6, wherein the light guide plate is an acrylic plate.   The backlight module according to claim 6, wherein the laser processing pattern is a volcano type.   The backlight module according to claim 6, wherein the laser processing pattern is spherical.   The backlight module according to claim 6, wherein the plurality of laser processing patterns are arranged in an array.   The backlight module according to claim 6, wherein the plurality of laser processing patterns are linearly arranged.   The backlight module according to claim 6, wherein the plurality of laser processing patterns are manufactured by an injection molding method using a mold processed by a laser.

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