TW201305622A - Method of manufacturing light guide plate - Google Patents

Abstract

A method of manufacturing a light guide plate includes following steps. A light-transmissive substrate having a first surface, a second surface, and a first light incident surface connecting the first surface and the second surface is provided. A first wedge part on the first surface near the first light incident surface of the light-transmissive substrate is manufactured by a mold so as to form a light guide plate. A thickness of the first wedge part reduces along a direction away from the first light incident surface.

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.

Since the liquid crystal display (LCD) itself does not have the function of emitting light, a backlight system must be provided under the liquid crystal display to provide a light source to achieve the display function. The conventional backlight system is composed of two basic parts: a light source and a light guide plate, wherein the light source is further divided into a cold cathode fluorescent lamp (CCFL) of a line source and a light emitting diode of a point source. Light emitting diode (LED). The light beam emitted by the light source is directly incident on the light guide plate and guided by the light guide plate to be uniformly emitted from the surface of the light guide plate.

In the prior art, in order to improve the light use efficiency, the light incident surface of the light guide plate on the light source side is made larger to sufficiently receive the light beam emitted by the light emitting diode. However, it is generally difficult to reduce the thickness of a large-sized (for example, 7 inches or more) light guide plate by the process of the injection table of the light guide plate. On the other hand, although the technique of forming a flat light guide plate by extrusion molding can control the minimum thickness of the flat light guide plate to 0.3 mm to 0.6 mm, in order to match the thickness of the flat light guide plate, a small-sized light-emitting diode is usually selected. As a light source, a light source device is formed with a flat light guide plate, because the technique of forming a flat light guide plate by extrusion molding cannot make the light incident surface of the light guide plate on the light source side larger. As a result, such a light source device will have the disadvantages of low light output performance, low lifetime, and inability to meet large-size applications.

In addition, the prior art also provides several fabrication techniques related to light guide plates or substrates. For example, U.S. Patent Publication No. 20070031106 discloses a method of making a light absorbing layer on a flat sheet. A structure related to a light guide plate is also disclosed in the Chinese Patent Publication No. 101243355 and the Republic of China Patent No. 594267, respectively. In addition, the Republic of China Patent Nos. I306806 and I332435 disclose the processing method of the plastic and the processing method of the surface pattern of the light guide plate, respectively.

The invention provides a method for manufacturing a light guide plate, which can effectively improve the matching degree between a thin light guide plate and a light source with a large thickness.

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

In order to achieve 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, including the following steps. A transparent substrate is provided. The light transmissive substrate has a first surface, a second surface, and a first light incident surface connecting the first surface and the second surface. Forming a first wedge portion on the first surface of the light transmissive substrate adjacent to the first light incident surface by using a mold to form a light guide plate, wherein the thickness of the first wedge portion is away from the first light incident surface Decrement.

In the manufacturing method of the light guide plate of the embodiment, the step of forming the first wedge portion on the first surface of the transparent substrate by using the mold near the first light incident surface comprises: filling the first space in the housing space of the mold a material, wherein the first material is different from the material of the light-transmitting substrate; the one end of the light-transmitting substrate adjacent to the first light-incident surface is placed in the accommodating space to make the first surface contact the first material; and the first material is cured On the first surface to form a first wedge.

In a method of fabricating a light guide plate according to an embodiment, the step of curing the first material on the first surface is to irradiate the first material in the accommodating space with light.

In a method of manufacturing a light guide plate according to an embodiment, the mold includes a first portion of the mold core and the second portion of the mold core, and the method of manufacturing the light guide plate further comprises combining the first portion of the mold core and the second portion of the mold core to form the mold. space.

In an embodiment, the method of manufacturing the light guide plate further comprises: separating the first portion of the mold core and the second portion of the mold core; and separating the light guide plate from the mold.

In an embodiment, the method of fabricating the light guide plate further comprises surface treating the contact surface of the mold and the first material to reduce the adsorption force of the first material and the mold.

In a method of fabricating a light guide plate according to an embodiment, the step of surface-treating the contact surface of the mold with the first material comprises applying a release agent to the contact surface of the mold and the first material.

In the manufacturing method of the light guide plate of the embodiment, the method further includes: forming a first light incident portion on the first light incident surface of the light transmissive substrate by using the mold, wherein the first light incident portion is connected to the first wedge portion.

In a method of fabricating a light guide plate according to an embodiment, the first light incident portion has a light-incident surface facing away from the light-transmitting substrate, and the light-incident surface has a plurality of optical microstructures.

In the manufacturing method of the light guide plate of the embodiment, the first wedge portion is formed on the first surface of the transparent substrate by the mold near the first light incident surface, and is formed on the first light incident surface of the transparent substrate. The step of filling the first light-injecting portion includes: filling a first material in the accommodating space of the mold, wherein the first material is different from the material of the light-transmitting substrate; and placing the end of the light-transmitting substrate adjacent to the first light-incident surface And maintaining a distance between the first light incident surface and the mold, so that the first surface and the first light incident surface contact the first material; and curing the first material on the first surface and the first light incident surface, The first wedge portion and the first light incident portion are respectively formed.

In a method of fabricating a light guide plate according to an embodiment, the first material is a light hardening resin or an ultraviolet light curing adhesive.

In a method of fabricating a light guide plate according to an embodiment, the light-transmitting substrate further has a second light-incident surface relative to the first light-incident surface, and the method for fabricating the light guide plate further comprises: approaching the second light-incident surface on the first surface The position creates a second wedge, wherein the thickness of the second wedge decreases as it moves away from the second entrance face.

In one embodiment, the method for fabricating the light guide plate further includes forming a second light incident portion on the second light incident surface of the light transmissive substrate by using the mold, and connecting the second light incident portion to the second wedge portion.

In a method of fabricating a light guide plate according to an embodiment, a difference between a refractive index of the first wedge portion and a refractive index of the transparent substrate is less than or equal to 0.15.

In a method of fabricating a light guide plate according to an embodiment, the thickness of the light transmissive substrate is less than or equal to 0.4 mm.

In a method of fabricating a light guide plate according to an embodiment, a diagonal length of the first surface of the light transmissive substrate is greater than or equal to 7 inches.

Based on the above, embodiments of the present invention can achieve at least one of the following advantages or effects. Since the method for fabricating the light guide plate according to the embodiment of the present invention is to form the first wedge portion on the first surface of the transparent substrate near the first light incident surface, the light guide plate can be closer to the light entrance side. Large thickness. Therefore, the light-incident side of the light guide plate can be disposed with a light source having a relatively large thickness, so that the problem that the light-emitting performance of the thin light-guide plate is lowered due to the use of the thin-type light source can be avoided.

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

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only directions referring to the additional drawings. Therefore, the directional terminology used is for the purpose of illustration and not limitation.

The manufacturing method of the light guide plate of this embodiment mainly includes two steps. A transparent substrate is provided, wherein the transparent substrate has a first surface, a second surface, and a first light incident surface connecting the first surface and the second surface. Forming a first wedge portion on a first surface of the transparent substrate adjacent to the first light incident surface by using a mold to form a light guide plate, wherein the thickness of the first wedge portion is away from the first light incident surface Decrement. By the above method, a thin light guide plate suitable for a light source having a large thickness can be produced. For an embodiment of the detailed production process, please refer to the related description of FIGS. 1A to 1I.

1A to 1I are schematic views showing a method of fabricating a light guide plate according to an embodiment of the present invention. Referring to FIG. 1A and FIG. 1B , the method for fabricating the light guide plate comprises combining the first portion of the mold core 110 of the mold 100 of FIG. 1A with the second portion of the mold core 120 to form the accommodating space 130 of FIG. 1B . In this embodiment, the first portion of the mold core 110 and the second portion of the mold core 120 are, for example, light transmissive mold cores.

Next, referring to FIG. 1D, the material M1 is filled in the accommodating space 130 of the mold 100. In the present embodiment, the material M1 is, for example, a photo-curing resin or an ultraviolet glue (UV glue), and the filling of the material M1 is performed, for example, through the dispensing nozzle 200, but the present invention Not limited to this. In addition, as shown in FIG. 1C, in order to reduce the adsorption force of the material M1 and the mold 100, the contact surface S1 of the mold 100 and the material M1 may be surface-treated before the step of filling the material M1 of FIG. 1D. In detail, the method of performing the surface treatment of FIG. 1C is, for example, applying the release agent M2 to the contact surface S1 of the mold 100 and the material M1, but the invention is not limited thereto. It should be noted that in other embodiments, the step of surface treatment of FIG. 1C may not be performed prior to the step of FIG. 1D.

Referring to FIG. 1E and FIG. 1F , a transparent substrate 310 is provided, and one end of the transparent substrate 310 adjacent to the light incident surface S4 is placed in the accommodating space 130 such that the surface S2 contacts the material M1 . The light-transmitting substrate 310 is fixed or moved by, for example, a jig 400. In addition, in the present embodiment, the light-transmitting substrate 310 is, for example, a flat substrate. In addition, as shown in FIG. 1F, the method for fabricating the light guide plate of the embodiment further includes maintaining the light incident surface S4 of the transparent substrate 310 and the mold 100 at a distance G1, so that the light incident surface S4 contacts the material M1, wherein The pitch G1 is greater than zero. In the present embodiment, the thickness T1 of the transparent substrate 310 is less than or equal to 0.4 millimeters (mm), and the diagonal line L (shown in FIG. 2) of the surface S2 of the transparent substrate 310 is longer than or equal to 7 inches. Therefore, the light-transmitting substrate 310 of the present embodiment is a light-transmissive substrate having a small thickness and a large size. Further, the light-transmitting substrate 310 is produced, for example, by extrusion, ejection, or rolling.

Then, as shown in FIG. 1G, the material M1 in the accommodating space 130 is solidified on the surface S2, and the wedge portion 320 is formed on the surface S2 of the transparent substrate 310 near the light incident surface S4. The thickness T2 of the wedge portion 320 decreases as it goes away from the light incident surface S4. In addition, the difference between the refractive index of the wedge portion 320 and the refractive index of the transparent substrate 310 is less than or equal to 0.15. In addition, in this embodiment, the method for fabricating the light guide plate further includes curing the material M1 on the light incident surface S4 to form the light incident portion 330, wherein the light incident portion 330 is connected to the wedge portion 320. At this point, the fabrication of the light guide plate 300 is completed. It should be noted that in other embodiments, the light guide plate 300 may not have the light incident portion 330. For example, if the light incident surface S4 of the transparent substrate 310 is in close contact with the bottom of the accommodating space 130, it is possible to form a light guide plate that does not have the light incident portion 330. In addition, the method of curing the material M1 on the surface S2 or the light incident surface S4 is, for example, irradiating the material M1 in the accommodating space 130 with the light 500, and the light 500 is, for example, ultraviolet light, and the mold 100 is, for example, a light transmitting mold to facilitate light. 500 passes through. Or, the material M1 in the accommodating space 130 is heated and baked to cure the material M1 on the surface S2 or the light incident surface S4.

Next, referring to FIG. 1H and FIG. 1I, after the curing of the material M1 is completed, the first portion of the mold core 110 and the second portion of the mold core 120 can be separated, and the light guide plate 300 can be taken out to make the light guide plate 300 and the mold 100. Separation. In addition, as shown in FIG. 1I, the light incident portion 330 of the light guide plate 300 of the present embodiment has a light incident surface S5 facing away from the transparent substrate 310, and the light incident surface S5 has a plurality of optical microstructures 332. These optical microstructures 332 are, for example, bumps, pits, ridges, indentations, or other suitable shaped optical microstructures, such as being transferred from the inner surface of the first portion of the mold core 110. The optical microstructure 332 can reduce the hot spot effect that is common in flat panel substrates. Therefore, the light guide plate 300 of the present embodiment is suitable for providing a surface light source with better uniformity. The light guide plate 300 described above is adapted to be combined with other optical components to form a backlight module.

FIG. 3 is a schematic diagram of a backlight module according to an embodiment of the invention. Referring to FIG. 3 , the backlight module 600 includes the light guide plate 300 , the light source 610 and the optical component 620 , wherein the light source 610 is disposed on one side of the wedge portion 320 of the light guide plate 300 , and the optical component 620 is disposed adjacent to one of the surfaces S3 . On the side, the optical element 620 is, for example, a reflective sheet. In the present embodiment, the light exit surface of the light guide plate 300 is, for example, the surface S2. However, in another embodiment, the light-emitting surface of the light guide plate 300 may also be the surface S3, and the position of the optical element 620 is disposed, for example, on one side of the surface S2. In addition to this, the light source 610 is, for example, a light emitting diode (LED).

It is to be noted that the light-transmitting substrate 310 of the present embodiment has a thinner thickness and a larger size. Therefore, the light guide plate 300 of the present embodiment is a light guide plate having a large size and a small thickness. However, since the light guide plate 300 of the present embodiment includes the wedge portion 320, the thickness T3 of the light guide plate 300 on the light incident side near the wedge portion 320 is large, so that the light guide plate 300 of the embodiment is suitable for a larger thickness. Light source 610. For example, the thickness T4 of the light source 610 can be greater than 0.4 mm, which is, for example, 0.6 mm or 0.8 mm, and the thickness T5 of the light-emitting region 612 of the light source 610 is, for example, greater than 0.3 mm. Therefore, since the thickness T3 of the light guide plate 300 is larger than the thickness T5 of the light-emitting region 612 of the light source 610, the light guide plate 300 can fully receive the light beam emitted by the light source 610 having a large light-emitting area 612, so that the backlight module 600 can be provided. A brighter surface source. In other words, the light guide plate 300 of the present embodiment does not have the problem that the thin light guide plate has a low light-emitting performance due to the combination of the thin light source. That is, the manufacturing method of the light guide plate of the present embodiment can produce a large-sized light source (for example, a light-emitting diode) with a large thickness and a high luminous efficiency, so that the backlight module 600 of the light guide plate 300 is provided. Highly uniform and high brightness surface light source.

Fig. 4 is a schematic view of a light guide plate 300' according to another embodiment of the present invention. Referring to FIG. 4, in another embodiment, the method for forming the light guide plate 300' further includes forming a wedge portion 320' relative to the surface S2 near the light incident surface S6, wherein the thickness T2' of the wedge portion 320' follows The direction away from the light incident surface S6 is decreased, and the light incident surface S6 is opposite to the light incident surface S4. In addition, the method for forming the light guide plate 300 ′ further includes forming the light incident portion 330 ′ on the light incident surface S6 of the transparent substrate 310 by using the mold 100 (shown in FIGS. 1A to 1I ), and the light incident portion 330 ′ and the wedge shape. The part 320' is connected. That is, the light guide plate 300' is a light guide plate with double side light entrance. In detail, the light source 610 shown in FIG. 3 can be respectively disposed on the two sides of the light guide plate 300' adjacent to the wedge portions 320 and 320', and the optical light of FIG. 3 can also be disposed on the side of the light guide plate 300' near the surface S3. Element 620 (eg, a reflective sheet). Similarly, the light guide plate 300' of the present embodiment is larger than the thicknesses T3 and T3' of the mechanical portions 320 and 320', so that the light guide plate 300' is adapted to match the light source 610 having a relatively large thickness, thereby using the light guide plate. The 300' backlight module provides a high uniformity and high brightness surface source. The manner of making the wedge portion 320' and the light incident portion 330' of the light guide plate 300' can be inferred from the related description of FIGS. 1A to 1I, and thus will not be described herein.

In summary, embodiments of the invention include at least one of the following advantages or benefits. Since the method for fabricating the light guide plate according to the embodiment of the present invention is to form the first wedge portion on the first surface of the transparent substrate near the first light incident surface, the light guide plate can be larger near the wedge portion. thickness of. Therefore, the light-incident side of the light guide plate can be disposed with a light source having a relatively large thickness, so that the problem that the light-emitting performance of the thin light-guide plate is lowered due to the use of the thin-type light source can be avoided.

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.

The terms "first", "second", "." used in the specification and claims are merely used to name the elements and are not intended to limit the upper or lower limits of the number of elements.

100. . . Mold

110. . . The first part of the mold

120. . . The second part of the mold

130. . . Housing space

200. . . Glue nozzle

300, 300’. . . Light guide

310. . . Light transmissive substrate

320, 320’. . . Wedge

330, 330’. . . Light entering department

332. . . Optical microstructure

400. . . Fixture

500. . . Light

600. . . Backlight module

610. . . light source

612. . . Luminous area

620. . . Optical element

M1. . . material

M2. . . Release agent

S1. . . Contact surface

S2, S3. . . surface

S4, S6. . . Glossy surface

S5. . . Bright side

T1~T5, T2', T3'. . . thickness

G1. . . spacing

L. . . diagonal

1A to 1I are schematic views showing a method of fabricating a light guide plate according to an embodiment of the present invention.

2 is a top plan view of the surface S2 of the light-transmitting substrate of FIG. 1F.

FIG. 3 is a schematic diagram of a backlight module according to an embodiment of the invention.

4 is a schematic view of a light guide plate according to another embodiment of the present invention.

100. . . Mold

110. . . The first part of the mold

120. . . The second part of the mold

130. . . Housing space

300. . . Light guide

310. . . Light transmissive substrate

320. . . Wedge

330. . . Light entering department

400. . . Fixture

500. . . Light

M1. . . material

S2, S3. . . surface

S4. . . Glossy surface

T2. . . thickness

G1. . . spacing

Claims (20)

A method for fabricating a light guide plate, comprising: providing a transparent substrate, the transparent substrate having a first surface, a second surface, and a first light incident surface connecting the first surface and the second surface; Forming a first wedge portion on the first surface of the transparent substrate adjacent to the first light incident surface to form a light guide plate, wherein a thickness of the first wedge portion is away from the first inlet Decrease in one direction of the glossy surface. The method of fabricating a light guide plate according to the first aspect of the invention, wherein the step of forming the first wedge portion on the first surface of the light transmissive substrate adjacent to the first light incident surface comprises: Filling a accommodating space of the mold with a first material, wherein the first material is different from the material of the transparent substrate; and placing the end of the transparent substrate adjacent to the first light incident surface into the accommodating a space in which the first surface contacts the first material; and the first material is cured on the first surface to form the first wedge. The method of fabricating a light guide plate according to claim 2, wherein the step of curing the first material on the first surface utilizes a light to illuminate the first material in the accommodating space. The method of manufacturing the light guide plate of claim 2, wherein the mold comprises a first portion of the mold core and a second portion of the mold core, and the method of manufacturing the light guide plate further comprises combining the first portion of the mold core with The second portion of the mold core forms the accommodating space. The method for fabricating a light guide plate according to claim 4, further comprising: separating the first portion of the mold core and the second portion of the mold core; and separating the light guide plate from the mold. The method for fabricating a light guide plate according to claim 2, further comprising surface treating the contact surface of the mold and the first material to reduce the adsorption force of the first material and the mold. The method of fabricating a light guide plate according to claim 6, wherein the step of surface-treating the mold and the contact surface of the first material comprises coating the mold with the contact surface of the first material Release agent. The method for fabricating a light guide plate according to claim 1, further comprising: forming a first light incident portion on the first light incident surface of the light transmissive substrate by using the mold, wherein the first light incident portion Connected to the first wedge. The method of fabricating a light guide plate according to claim 8, wherein the first light incident portion has a light-incident surface facing away from the light-transmitting substrate, and the light-incident surface has a plurality of optical microstructures. The method of fabricating a light guide plate according to claim 8 , wherein the first wedge portion is formed on the first surface of the transparent substrate adjacent to the first light incident surface by using the mold, and The step of forming the first light incident portion on the first light incident surface of the light transmissive substrate comprises: filling a first space of a space of the mold, wherein the first material and the material of the light transmissive substrate Differently, the one end of the transparent substrate adjacent to the first light incident surface is placed in the accommodating space, and the first light incident surface is kept at a distance from the mold, so that the first surface and the first surface The light incident surface contacts the first material; and the first material is cured on the first surface and the first light incident surface to form the first wedge portion and the first light incident portion, respectively. The method of fabricating a light guide plate according to claim 10, wherein the first material is a light hardening resin or an ultraviolet light curing glue. The method of manufacturing a light guide plate according to claim 8, wherein the mold comprises a first portion of the mold core and a second portion of the mold core, and the method of manufacturing the light guide plate further comprises combining the first portion of the mold core with The second portion of the mold core forms the accommodating space. The method for fabricating a light guide plate according to claim 12, further comprising: separating the first portion of the mold core and the second portion of the mold core; and separating the light guide plate from the mold. The method for fabricating a light guide plate according to claim 13, further comprising surface treating the contact surface of the mold and the first material to reduce the adsorption force of the first material and the mold. The method of fabricating a light guide plate according to claim 14, wherein the step of surface-treating the mold and the contact surface of the first material comprises coating the mold with the contact surface of the first material Release agent. The method of manufacturing the light guide plate according to the first aspect of the invention, wherein the light-transmitting substrate further has a second light-incident surface relative to the first light-incident surface, and the method for manufacturing the light guide plate is further included in the first A second wedge portion is formed on a surface adjacent to the second light incident surface, wherein a thickness of the second wedge portion decreases in a direction away from the second light incident surface. The method for fabricating a light guide plate according to claim 16, further comprising forming a second light incident portion on the second light incident surface of the light transmissive substrate by using the mold, and the second light incident portion is The second wedge is connected. The method of fabricating a light guide plate according to claim 1, wherein a difference between a refractive index of the first wedge portion and a refractive index of the transparent substrate is less than or equal to 0.15. The method of fabricating a light guide plate according to claim 1, wherein the transparent substrate has a thickness of less than or equal to 0.4 mm. The method of manufacturing the light guide plate of claim 1, wherein the first surface of the transparent substrate has a diagonal length greater than or equal to 7 inches.