TWI464466B - Method for manufacturing light guide - Google Patents

Description

Light guide plate manufacturing method

The invention relates to the technical field of light guide plate fabrication, and in particular to a method for manufacturing a light guide plate.

With the development of flat-panel liquid crystal displays, light guide plates, which are important components of liquid crystal display light source systems, have received increasing attention. The light guide plate is usually made of plastic having high light transmittance, and is used for guiding the transmission direction of the light beam from the light source, and converting the line light source or the point light source into a surface light source.

In order to maximize the utilization of the light beam emitted from the light source, the following two methods are generally used: (1) plating the reflective film on the surface of the light guide plate except the incident surface; and (2) bonding the reflective sheet to the surface of the light guide plate except the incident surface. . For the first approach, the light guide plate and the reflection sheet are separately produced, and then the reflection sheet is attached to the surface of the light guide plate except the incident surface. During the bonding process, the reflective sheet easily rubs against the surface of the light guide plate to cause scratches, thereby affecting the brightness. For the second approach, the process time required for plating the reflective film is long, and the coating process on the plastic surface is harsh and the yield is low, which is not conducive to saving production cost and improving production efficiency.

In view of this, it is necessary to provide a simple and fast method for fabricating a light guide plate to improve production efficiency and reduce cost.

Hereinafter, an example of a light guide plate with high production efficiency and low cost will be described by taking an embodiment as an example. law.

The manufacturing method of the light guide plate comprises the steps of: providing an injection molding device and a reflection sheet, the injection molding device comprising an injection device and a molding device, the molding device comprising a first mold and a second mold disposed together, the first mold The first clamping mold has a cavity facing the inside thereof, and is provided with a runner communicating with the cavity, the second mold is provided with a second clamping surface, and the first clamping surface is combined with the second clamping after the clamping The reflective surface includes a reflective surface and a surface opposite to the reflective surface; the first mold and the second mold are used to clamp the reflective sheet, and the reflective surface is attached to the first mold surface to close the mold a cavity, the second clamping surface completely conforms to the surface to support the reflective sheet by the second clamping surface; the resin hot melt is sprayed into the cavity by a sprue and filled up The cavity, thereby forming a light guiding portion on the surface of the reflecting surface; cooling, separating the first mold and the second mold.

Compared with the prior art, the light guide plate manufacturing method of the present invention forms a light guiding portion directly on the reflecting surface of the reflecting sheet by the injection molding process, thereby forming a light guiding plate integrally formed with the reflecting sheet, without the surface of the light guiding portion. Sputtering the reflective film or separately producing the light guide plate and the reflection sheet and then bonding the light guide plate and the reflection sheet into one body, thereby reducing the production process, reducing the cost and improving the production efficiency.

10‧‧‧Injection molding device

20‧‧‧reflector

11‧‧‧Material conveying device

13‧‧‧Spray device

12‧‧‧Molding device

121‧‧‧First mould

122‧‧‧Second mold

1211‧‧‧First clamping surface

1212‧‧‧Second mold surface

1210‧‧‧ cavity

1222‧‧‧Runner

21‧‧‧Substrate layer

22‧‧‧reflective layer

221‧‧‧reflecting surface

30‧‧‧Light Guide

50‧‧‧Light guide plate

FIG. 1 is a flow chart of a method for fabricating a light guide plate according to an embodiment of the present technical solution.

2 is a schematic view of an injection molding apparatus, a molding apparatus, and a reflection sheet used in a method of manufacturing a light guide plate according to an embodiment of the present technical solution.

Fig. 3 is a schematic view showing the use of the molding apparatus shown in Fig. 2 for holding a reflection sheet.

4 is a light guiding portion formed on the reflecting surface of the reflecting sheet by using the injection molding device shown in FIG. Schematic diagram.

FIG. 5 is a schematic view of a light guide plate prepared by the method for fabricating the light guide plate shown in FIG. 1. FIG.

The method for fabricating the light guide plate provided by the technical solution is described in detail below with reference to the embodiments and the accompanying drawings.

The method for manufacturing a light guide plate provided in this embodiment includes the following steps:

First, referring to Fig. 2, an injection molding apparatus 10 and a reflection sheet 20 are provided.

The injection molding device can be an injection molding machine commonly used for injection molding a light guide plate. The injection molding apparatus 10 provided in this embodiment includes a material conveying device 11, an injection device 13 connected to the material conveying device 11, and a molding device 12 disposed opposite to the injection device 13.

The material conveying device 11 generally includes a hopper, a feeding section connected to the hopper, a homogenizing section connected to the feeding section, and a holding section connected to the spraying device 13 for heating the high light transmissive resin to its melting temperature. The resin is melt processed to form a hot melt by the shearing force of the screw corresponding to the feeding section and the homogenizing section, and the hot melt is transferred to the spraying device 13.

The molding apparatus 12 includes a first mold 121 and a second mold 122 that is matched with the first mold 121. The first mold 121 is provided with a first mold clamping surface 1211, and the second mold 122 is provided with a second mold clamping surface 1212. The first mold 121 is provided with a cavity 1210 from the first mold clamping surface 1211 and a runner 1222 communicating with the cavity 1210. After clamping, the first clamping surface 1211 is in full contact with the second clamping surface 1212, and the cavity 1210 is in communication with the outside through the runner 1222. The shape and size of the cavity 1210 match the shape and size of the light guiding portion of the light guide plate to be produced.

The spraying device 13 can be a nozzle for injecting the resin hot melt conveyed by the material conveying device 11 into the cavity 1210 through the runner 1222.

The reflection sheet 20 is a reflection sheet commonly used in a backlight module, such as a reflection sheet having a metal silver layer on its surface or a reflection sheet having a white reflector inside. In the present embodiment, the reflection sheet 20 includes a base material layer 21 and a reflective layer 22 provided on the surface of the base material layer 21. The material of the substrate layer 21 may be plastic, glass, ceramic, metal or other commonly used materials, and the material of the reflective layer 22 may be metallic silver having a reflecting surface 221 .

Next, the reflection sheet 20 is held by the molding device 12, and the reflection sheet 20 is closed to the cavity 1210.

Referring to FIG. 2 and FIG. 3 together, the reflective sheet 20 can be first positioned between the first mold 121 and the second mold 122 by a robot (not shown), and then the mold is closed. After the mold is closed, the reflecting surface 221 and the surface facing the reflecting surface 221 are respectively bonded to the first mold clamping surface 1211 and the second mold clamping surface 1212. Due to the presence of the reflection sheet 20, the cavity 1210 is changed from the open state to the state in which only the runner 1222 communicates with the outside.

Finally, the resin hot melt is injected into the cavity 1210 through the runner 1222 by the spraying device 13 and fills the cavity 1210, and is cooled to separate the first die 121 and the second die 122.

The resin has high light transmittance, which may be polyethylene terephthalate or polycarbonate. Referring to FIG. 2 to FIG. 4 together, since the reflection sheet 20 is sandwiched between the first clamping surface 1211 and the second clamping surface 1212, and the reflecting surface 221 is located on one side of the runner 1222, The resin hot melt is sprayed into the cavity 1210 through the runner 1222 and fills the cavity 1210, and then cooled to form a light guiding portion 30 conforming to the shape and size of the cavity 1210 on the surface of the reflecting surface 221 of the reflecting sheet 20. The first mold 121 and the second mold 122 are separated to obtain the light guide plate 50 in which the light guiding portion 30 and the reflection sheet 20 are integrated.

The method for fabricating the light guide plate of the embodiment may also form a light guiding portion on a surface opposite to the reflecting surface 221 , and the manufacturing method may further include cutting the reflecting sheet 20 after taking out the light guiding plate 50 to make the size and shape thereof and the light guiding portion. 30 is the same size and shape. After separating the first mold 121 and the second mold 122, the next reflective sheet is positioned between the first mold 121 and the second mold 122 by a robot, and the light guide plate 50 can be mass-produced by repeating steps 2 and 3.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

Claims (4)

A manufacturing method of a light guide plate, comprising the steps of: providing an injection molding device and a reflection sheet, the injection molding device comprising a spraying device and a molding device, the molding device comprising a first mold and a second mold disposed together, the first mold a mold cavity is opened from the first mold clamping surface, the first mold is provided with a runner communicating with the mold cavity, and the second mold is provided with a second mold clamping surface, and the first mold surface is closed after the mold clamping Fully contacting the second mold clamping surface, the reflection sheet includes a reflective surface and a surface opposite to the reflective surface; the first mold and the second mold are used to clamp the reflective sheet, and the reflective surface is attached to the first mold clamping The surface is closed to close the cavity, the second clamping surface is completely conformed to the surface to support the reflective sheet by the second clamping surface; and the resin hot melt is sprayed to the cavity by a sprue by using a spraying device And filling the cavity, thereby forming a light guiding portion on the surface of the reflecting sheet: cooling, separating the first mold and the second mold, and preparing a light guiding plate integrally formed with the reflecting sheet. The method for fabricating a light guide plate according to the first aspect of the invention, wherein the method further comprises: after separating the first mold and the second mold, the reflective sheet is cut to have a shape and a size conforming to the light guiding portion. The method for producing a light guide plate according to claim 1, wherein the resin is polyethylene terephthalate or polycarbonate. The method of fabricating a light guide plate according to claim 1, wherein the reflective sheet comprises a substrate layer and a reflective layer disposed on a surface of the substrate layer, and the reflective layer is made of metallic silver.