TW201310094A - Manufacturing method of light guide plate - Google Patents

Abstract

A manufacturing method of light guide plate is provided. First, a mold is provided, wherein the mold has a mold cavity and a plurality of restoring pins. Then, a film is located in the mold cavity, and the film is pushed to contact an inner wall of the mold cavity by the restoring pins, wherein the film has an optical microstructure. A plastic material is injected into the mold cavity and integrated with the film to form a light guide plate.

Description

Light guide plate manufacturing method

The present invention relates to a method of fabricating an optical component, and more particularly to a method of fabricating a light guide.

The backlight module usually includes a light guide plate, and the light guide plate serves to guide the direction of light generated by the light source, thereby improving the brightness of the panel and ensuring the uniformity of the brightness of the panel, so as to point the light source or line in the backlight module. The light source is converted into a surface light source and supplied to the liquid crystal display panel. Therefore, the material properties of the light guide plate and the design and manufacture of the surface optical microstructure are all related to the overall optical design and brightness and uniformity control of the backlight module.

As the electronic device is thinned, the light guide plate of the backlight module is also designed to have a relatively thin thickness. It is difficult to make a large-sized and thin-shaped light guide plate by an injection molding process. If an optical microstructure of the surface of the light guide plate is formed by an injection molding process, the process is more difficult and the yield is lowered, and the yield is lowered. The optical microstructure is easily damaged during the molding.

Taiwan Patent No. I280446 discloses a method of manufacturing a light guide plate. When a light guide plate is formed in a cavity, a layer of a transfer material located in a cavity is transferred to a light guide plate. Taiwan Patent No. M326116 discloses an in-mold transfer material having no release layer between the carrier and the protective layer, and the protective layer is formed directly on the carrier.

The invention provides a method for fabricating a light guide plate, which has better yield.

Other objects and advantages of the present invention will become apparent from the technical features disclosed herein.

For one or a part or all of the above or other purposes, an embodiment of the present invention provides a method of fabricating a light guide plate. First, a mold is provided in which the mold has a cavity and a plurality of return pins. Next, a film is placed in the cavity, and the film is pushed against the inner wall of the cavity by the return pins, wherein the film has an optical microstructure. A plastic is injected into the cavity, wherein the plastic pushes the return pins out of the cavity, and the plastic is bonded to the film to form a light guide.

Based on the above, in the above embodiment of the present invention, the film having the optical microstructure is first placed in the cavity, and then the plastic injected into the cavity is combined with the film to form a light guide plate having an optical microstructure, so The optical microstructure of the surface of the light guide plate is formed by the injection molding process, which can reduce the difficulty of the light guide plate process and improve the process yield. In addition, since the optical microstructure is not formed by injection molding, the mold does not have a mold structure corresponding to the optical microstructure, and the force between the optical microstructure and the corresponding mold structure can be avoided during demolding. Structural damage, further improve process yield. In addition, the film can be positioned in the correct position in the cavity by the push-back of the film to allow the plastic to properly bond to the film.

The above described features and advantages of the invention will be apparent from the following description.

The foregoing and other objects, features, and advantages of the invention will be apparent from the Detailed Description The directional terms mentioned in the following embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only directions referring to the additional schema. Therefore, the directional terminology used is for the purpose of illustration and not limitation.

1 is a flow chart of a method for fabricating a light guide plate according to an embodiment of the invention. 2A to 2D are schematic views showing a method of fabricating the light guide plate of FIG. 1. Referring to FIG. 1, first, a mold 50 is provided as shown in FIG. 2A, wherein the mold 50 has a cavity 52 and a plurality of return pins 54 (step S602). Next, a film 110 is placed in the cavity 52 as shown in FIG. 2B, and the film 110 is pushed against the inner wall of the cavity 52 by the return pins 54, wherein the film 110 has an optical microstructure 112 (step S604). ). As shown in FIG. 2C, a plastic 120 is injected into the cavity 52, wherein the plastic 120 pushes the return pins 54 out of the cavity 52, and the plastic 120 is solidified and bonded to the film 110 to form the light guide plate 100 as shown in FIG. 2D. The light-emitting surface 100a of the light guide plate 100 has the above-described optical microstructures 112.

In the above process of fabricating the light guide plate 100, the film 110 having the optical microstructures 112 is first placed in the cavity 52, and then the plastic 120 injected into the cavity 52 is combined with the film 110 to form an optical microstructure 112. Since the light guide plate 100 is formed, the optical microstructures 112 on the surface of the light guide plate 100 are not required to be formed by the injection molding process, thereby reducing the difficulty of the process of the light guide plate 100 and improving the process yield. In addition, since the optical microstructures 112 are not formed by injection molding, the mold 50 does not have a mold structure corresponding to the optical microstructures 112, and the mold release structure is prevented from being between the optical microstructures 112 and the corresponding mold structure. The force causes structural damage and further improves process yield. In addition, the film 110 can be positioned in the correct position in the cavity 52 by the push of the return pin 54 to the film 110 to enable the plastic 120 to properly bond with the film 110.

The material of the plastic 120 is, for example, polymethyl methacrylate (PMMA), polycarbonate (PC), optical rubber or other suitable materials, which is not limited by the present invention.

3A and 3B are partial schematic views showing a method of fabricating the light guide plate of FIG. 1. The mold 50 of the present embodiment includes a male mold 50a and a female mold 50b. In step S604, the user can place the film 120 into the cavity 52 as follows. First, a film material 60 is provided between the master 50b and the male mold 50a as shown in FIG. 3A, and the film material 60 has an optical microstructure 112. Next, as shown in FIG. 3B, the male mold 50a is clamped to the master mold 50b to form a cavity 52 in which the film material 60 is cut by the mold clamping of the male mold 50a and the female mold 50b to form the film 110.

In detail, the film 110 of the present embodiment has a first surface 110a and a second surface 110b opposite to each other. The optical microstructure 112 is located on the first surface 110a, and the plastic 120 is adapted to be bonded to the second surface 110b of the film 110. In order to enable the plastic 120 to be smoothly bonded to the film 110, a primer 140 may be provided on the second surface 110b of the film 110 such that the film 110 is bonded to the plastic 120 by the primer 140 as shown in FIG. 2C.

4 is a schematic view of the film of FIG. 2B covered by a protective layer. A protective layer 130 can be provided on the first surface 110a to cover the optical microstructures 112 as shown in FIG. 4, such that the optical microstructures 112 can be protected by the protective layer 130 during shipment or during fabrication of the film 110. Before the film 110 is placed in the cavity 52, the protective layer 130 needs to be removed to facilitate subsequent processing.

As shown in FIG. 2A, each of the return pins 54 includes an elastic portion 54a, and the elastic portion 54a is coupled to the mold 50. Each of the return pins 54 is adapted to push the film 110 against the inner wall of the cavity 52 as shown in Fig. 2B by the elastic force of the elastic portion 54a. When the plastic 120 is injected into the cavity 52 as shown in FIG. 2C, the plastic 120 will push the return pins 54 out of the cavity 52 against the elastic force of the respective elastic portions 54a. In other embodiments, the elastic force may be provided by other suitable forms of resilient members, which are not limited in the present invention.

In the process of the light guide plate, in addition to forming the optical microstructures 112 on the light-emitting surface 100a of the light guide plate 100 in the embodiment shown in FIGS. 2A to 2D, an optical microstructure can be formed on the light-incident side of the light guide plate 100, This is illustrated by the following figures.

5A to 5D are partial schematic diagrams showing a method of fabricating a light guide plate according to another embodiment of the present invention. First, a male mold 50c, a master mold 50d, and a film material 70 are provided as shown in FIG. 5A, and the film material 70 has an optical microstructure 212. Next, as shown in FIG. 5B, the lateral slider 80 is driven to move toward the cavity 56 and the film material 70 is cut to form a film 210 in the cavity 56. After the plastic 220 is injected into the cavity 56 as shown in FIG. 5C, the plastic 220 is combined with the film 210 to form the light guide plate 200 shown in FIG. 5D, and the optical microstructure 212 is located on the light incident side 200b of the light guide plate 200. In other embodiments, the relative positions of the mold, the lateral slider, and the film material are configured by other suitable methods, and the optical microstructures 212 are formed on the light incident side 200b of the light guide plate 200. Limit it. FIG. 6 is a schematic view showing a light incident side of a light guide plate according to another embodiment of the present invention. By forming the optical microstructure 312 on the light incident side surface 300b of the light guide plate 300, the incident light of the light source 90 can be increased from the light type L1 to the light type L2 to increase the area of the light incident side surface 300b of the light guide plate 300 to maintain Good light quality.

Figure 7 is a partial plan view of a light guide plate according to another embodiment of the present invention. The present invention does not limit the form of the optical microstructure. The optical microstructure 112 of FIG. 2D or the optical microstructure 212 of FIG. 5D may be composed of a plurality of V-shaped grooves, such as the optical microstructure 312 of FIG. The optical microstructure 412 of the light guide plate 400 of FIG. 7 is composed of a plurality of hexagonal structures, or other suitable structure capable of controlling the advancing direction of the light, so that the light emitted through the light guide plate has Appropriate brightness and uniformity.

In summary, in the above embodiments of the present invention, a film having an optical microstructure is first placed in a cavity, and then the plastic injected into the cavity is combined with the film to form a light guide plate having an optical microstructure. Therefore, the optical microstructure of the surface of the light guide plate is not required to be formed by the injection molding process, thereby reducing the difficulty of the process of the light guide plate and improving the process yield. In addition, since the optical microstructure is not formed by injection molding, the mold does not have a mold structure corresponding to the optical microstructure, and the force between the optical microstructure and the corresponding mold structure can be avoided during demolding. Structural damage, further improve process yield. In addition, the film can be positioned in the correct position in the cavity by the push-back of the film to allow the plastic to properly bond to the film.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention. In addition, the terms "first", "second" and the like mentioned in the specification or the scope of the claims are only used to name the elements or distinguish different embodiments or ranges, and are not intended to limit the number of elements. Upper or lower limit.

50. . . Mold

50a, 50c. . . Public model

50b, 50d. . . Master model

52, 56. . . Cavity

54. . . Return pin

54a. . . Elastic part

60, 70. . . Film material

80. . . Lateral slider

90. . . light source

100, 200, 300, 400. . . Light guide

100a. . . Glossy surface

110, 210. . . film

110a. . . First surface

110b. . . Second surface

112, 212, 312, 412. . . Optical microstructure

120, 220. . . plastic

130. . . The protective layer

140. . . Primer

200b, 300b. . . Light side

L1, L2. . . Light type

S602~S606. . . step

1 is a flow chart of a method for fabricating a light guide plate according to an embodiment of the invention.

2A to 2D are schematic views showing a method of fabricating the light guide plate of FIG. 1.

3A and 3B are partial schematic views showing a method of fabricating the light guide plate of FIG. 1.

4 is a schematic view of the film of FIG. 2B covered by a protective layer.

5A to 5D are partial schematic diagrams showing a method of fabricating a light guide plate according to another embodiment of the present invention.

FIG. 6 is a schematic view showing a light incident side of a light guide plate according to another embodiment of the present invention.

Figure 7 is a partial plan view of a light guide plate according to another embodiment of the present invention.

50. . . Mold

50a. . . Public model

50b. . . Master model

52. . . Cavity

54. . . Return pin

54a. . . Elastic part

110. . . film

110a. . . First surface

110b. . . Second surface

112. . . Optical microstructure

120. . . plastic

140. . . Primer

Claims (10)

A method for manufacturing a light guide plate, comprising: providing a mold, wherein the mold has a cavity and a plurality of return pins; placing a film into the cavity, and pushing the film by the return pins In the inner wall of the cavity, wherein the film has an optical microstructure; and a plastic is injected into the cavity, wherein the plastic pushes the return pins out of the cavity, and the plastic is bonded to the film to form a Light guide plate. The method of manufacturing a light guide plate according to claim 1, wherein the mold comprises a master mold and a male mold, and the step of inserting the film into the mold cavity comprises: providing a film material to the master mold Between the male molds; and clamping the male mold to the female mold to form the mold cavity, wherein the film material is cut by the mold clamping of the male mold and the female mold to form the film. The method of fabricating a light guide plate according to claim 1, wherein the film has a first surface and a second surface, the optical microstructure is located on the first surface, and the plastic is adapted to be bonded to the film. The second surface. The method for fabricating a light guide plate according to claim 3, further comprising: providing a protective layer on the first surface to cover the optical microstructure; and moving the film before placing the film into the cavity In addition to the protective layer. The method of fabricating a light guide plate according to claim 3, wherein the step of inserting the film into the cavity comprises: providing a primer on the second surface, the primer being adapted to be combined with the plastic. The method of fabricating a light guide plate according to claim 1, wherein the optical microstructure comprises a plurality of semicircular bumps, a plurality of V-shaped grooves or a plurality of hexagonal structures. The method of fabricating a light guide plate according to the first aspect of the invention, wherein after the plastic is bonded to the film to form the light guide plate, the optical microstructure is located on a light exit surface of the light guide plate. The method of fabricating a light guide plate according to claim 1, wherein the optical microstructure is located on a light incident side of the light guide plate after the plastic is bonded to the film to form the light guide plate. The method for fabricating a light guide plate according to claim 1, wherein the plastic material comprises polymethyl methacrylate (PMMA), polycarbonate (PC) or optical rubber. The method of manufacturing the light guide plate of claim 1, wherein each of the return pins includes an elastic portion connected to the mold, and each of the return pins is adapted to be elastically biased by the elastic portion The film is pushed against the inner wall of the cavity, and the portion of the plastic that pushes the return pins out of the cavity comprises: the plastic pushing the return pins out of the cavity against the elastic force of each of the elastic portions.