TWI666477B - Light guide plate with high light uniformity and manufacturing method thereof - Google Patents

Abstract

The invention discloses a light guide plate with high light uniformity and a manufacturing method thereof. The light guide plate has a light entrance surface and a light exit surface vertically adjacent to the light entrance surface. The light guide plate further includes a plurality of first recessed grooves and a plurality of first recessed grooves. Two recessed trenches. The first depressed groove is extruded and formed on the light-emitting surface through an extruding roller, and has a first depth of 50 to 90 μm. The second depressed groove is extruded and formed on the light-emitting surface, and has a second depth of 10 to 30 μm. The first recessed grooves are staggered, and grooves of two depths can be formed by a single imprint through the printing roller. In this way, the second recessed groove eliminates the direct spray pattern caused by the first recessed groove adjacent to the light incident surface area, and the first recessed groove eliminates the stagger caused by the second recessed groove near the light incident surface area. This phenomenon can improve the overall light output.

Description

Light guide plate with high light uniformity and manufacturing method thereof

The present invention relates to the field of light guide elements, and particularly relates to a light guide plate with high uniformity of light emission and a manufacturing method thereof.

The light guide plate has excellent optical guiding characteristics, and has been widely used in various electronic devices that must have a function of emitting light or lighting for providing light. In order to enable electronic devices such as displays with light guide plates to have better image and brightness presentation, industry developers in this field mostly work towards the goal of how to make the light guide plate emit light more uniformly.

In order to make the light guide plate have the required light presentation, optical microstructures are generally designed on the light guide plate to facilitate the adjustment of the light output state. With higher standards and multiple light output requirements, the optical structure of the light guide plate has gradually become more complicated. In order to make it easier to produce light guide plates with complex structures, most of the current injection molding processes are used, especially for protruding micro The structure of the light guide plate can only be produced through injection molding. The injection molding process is specifically based on the structural characteristics of the light guide plate to be formed, and then related processing is performed on the mold, and then the filler is injected into the injection molding mold and released after curing. The structures thereon are formed together. However, the aforementioned method has its production limit for large-size light guide plates. When it is intended to produce large-size light guide plates, the volume of the injection molding mold must be designed to correspond to the size. When the mold is too large, uneven filling is likely to occur. Phenomenon, resulting in uneven thickness or even cracking of the finished product after demolding. On the other hand, thin light guide plates are not suitable for manufacturing through injection molding. When it is low, in addition to the difficulty of designing and constructing the corresponding mold, the light guide plate is also easily broken when the mold is released after curing, which causes a problem of low production yield.

Therefore, how to effectively improve the uniformity of light output of the light guide plate and facilitate rapid mass production is a problem that needs to be solved urgently.

In view of this, one object of the present invention is to provide a light guide plate with high light uniformity and a manufacturing method thereof, so as to effectively solve the problem of uneven light output generated by the current light guide plate during application, and is beneficial to rapid production and manufacturing.

In order to achieve the above object, the present invention discloses, in an embodiment, a light guide plate with high light uniformity, which has a light incident surface and a light emitting surface. The light incident surface is used to receive light from a light source. The smooth surface is vertically adjacent to each other and includes: a plurality of first recessed grooves extruded and formed on the light emitting surface with a first depth of 50-90 μm; and a plurality of second recessed grooves extruded and formed on the light emitting surface and has a first The two depths are 10 to 30 μm, and are staggered with the plurality of first recessed trenches; thereby, the second recessed trenches eliminate direct spray patterns caused by the first recessed trenches adjacent to the light incident surface area. Phenomenon, and the first recessed grooves eliminate the staggered phenomenon caused by the second recessed grooves adjacent to the light incident surface area, and can greatly improve the light uniformity of the light guide plate.

Following the foregoing embodiment, it is disclosed in one embodiment that the first recessed trenches and the second recessed trenches are continuously adjacent to each other to have a better uniform light effect.

Or as mentioned in another embodiment, the first recessed trenches and the second recessed trenches are spaced apart, and any one of the first recessed trenches and the second recessed trenches are adjacent to each other. The system is flat, so that it can also have better uniform light effect.

In addition, in order to improve the uniform light efficiency of the recessed trenches, in yet another embodiment, the first recessed trenches and the second recessed trenches are V-shaped and have two trench slopes. The setting angle is between 70 ~ 90 degrees.

The invention also discloses, in an embodiment, a method for manufacturing a light guide plate with high light uniformity, including the following steps: providing a light guide plate, the light guide plate having a light entrance surface and a light exit surface, and the light exit The surface is vertically adjacent to the light incident surface; a printing roller is provided, the printing roller has a plurality of first ribs and a plurality of second ribs, and the first ribs are pressed into the guide with a first height of 50 to 90 μm. Light plate, the second raised ribs are pushed into the light guide plate with a second height of 10-30 μm, and the first raised ribs and the second raised ribs are staggered; and on the light emitting surface of the light guide plate Pressing to form a plurality of first recessed trenches and a plurality of second recessed trenches. The first recessed trenches have a first depth of 50 to 90 μm, and the second recessed trenches have a second depth of 10 to 30 μm. And the first recessed trenches and the second recessed trenches are staggered. Thus, the first recessed groove and the second recessed groove having different depths can be formed simultaneously in a single pressing process by the pressing roller, which can effectively improve the production speed of the light guide plate and improve the yield of the product. The manufactured light guide plate product can effectively eliminate the optical phenomenon of uneven light and dark distribution when applied.

In one embodiment, the first raised ribs and the second raised ribs are continuously adjacent to each other, so that the first recessed grooves and the second recessed grooves corresponding to the continuous adjacent settings can be formed by printing. Meet the light output requirements of the light guide plate.

In another embodiment, the first ribs and the second ribs are spaced apart, and there is a plane between any one of the adjacent first ribs and the second ribs, thereby The first recessed groove and the second recessed groove corresponding to the interval can be formed by printing to meet the light output requirements of the light guide plate.

In addition, preferably, in another embodiment, the first ribs and the second ribs are V-shaped and have two rib ribs, and the angles between the rib ribs are between 70 ~ 90 degrees, thereby forming a first recessed trench and a second recessed trench in a V-shaped structure by press printing.

In summary, the light guide plate with high uniformity of light disclosed by the present invention and the manufacturing method thereof can eliminate the phenomenon of direct spraying or staggering caused when a recessed groove is provided to improve the overall light output, thereby ensuring that The overall light output of the light guide plate is uniform to prevent the problem of uneven light. In addition, through extrusion printing, in addition to improving the product processing speed, it also solves the problem of difficult to apply large-sized thin light guide plates, and provides more excellent optical products that meet market demand.

1‧‧‧light guide

10‧‧‧ Light surface

11‧‧‧ light surface

12‧‧‧ the first recessed trench

13‧‧‧Second recessed trench

14‧‧‧ The groove slope of the first recessed groove

15‧‧‧Groove slope of the second recessed groove

A‧‧‧first depth

B‧‧‧Second Depth

α‧‧‧ Angle of the groove bevel

2‧‧‧press printing roller

20‧‧‧The first raised rib

21‧‧‧Second convex rib

22‧‧‧ The rib of the first rib

23‧‧‧ the rib of the second rib

β‧‧‧ Angle of convex rib

S01 ~ S03‧‧‧step

FIG. 1 is a schematic perspective view of a light guide plate according to a preferred embodiment of the present invention.

FIG. 2 is a schematic plan view of a light guide plate according to a preferred embodiment of the present invention.

FIG. 3 is a schematic plan view of a light guide plate according to another embodiment of the present invention.

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

FIG. 5 is a flowchart of steps of a method for manufacturing a light guide plate according to a preferred embodiment of the present invention.

FIG. 6 is a schematic diagram of an application of a press roller according to a preferred embodiment of the present invention.

FIG. 7 is a schematic diagram of the application of the press roller in another implementation state of the preferred embodiment of the present invention.

FIG. 8 is a schematic diagram of staggered patterns generated when a light guide plate is applied.

Figure 9 is a schematic view of the direct spray pattern generated when the light guide plate is applied.

Nowadays, in order to improve the light uniformity of the light guide plate, it is seen that a plurality of groove structures having the same depth are provided on the surface of the light guide plate, so that the groove structure can be used to make the light guide plate bright and uniform. Evenness is improved. However, the inventor's practice and experiments have found that although the groove structure can increase the brightness at the time of light output, the groove structure can cause counter-effects such as uneven distribution of light and dark or excessively bright in some areas of the light emitting surface. The effect is due to the trench depth. When the depth of the trench structure is shallow, the staggered pattern of excessive light splitting will be generated in the area adjacent to the light incident surface, as shown in Figure 8. When the depth of the trench structure is deep, a straight line will appear near the light incident surface. Spraying phenomenon, as shown in Figure 9. Therefore, after the groove structure is provided to improve the light output, the light output from the light guide plate can be maintained uniformly. The present inventor conceived and proposed the following technical content.

Please refer to FIGS. 1 and 2, which are three-dimensional schematic diagrams and cross-sectional schematic diagrams of a light guide plate according to a preferred embodiment of the present invention. The present invention discloses a light guide plate 1 with high uniformity of light output. The light guide plate 1 has a light incident surface 10 and a light emitting surface 11. The light incident surface 10 is used for receiving light from a light source. The light emitting surface 11 is vertically adjacent to the light incident surface 10. The light guide plate 1 includes a plurality of first recessed trenches 12 and a plurality of second recessed trenches 13.

The first recessed grooves 12 are extruded and formed on the light emitting surface 11 and have a first depth A of 50 to 90 μm. The second recessed grooves 13 are also extruded and formed on the light emitting surface 11 and have a second depth B. It is 10-30 μm, and the second recessed trenches 13 and the first recessed trenches 12 are staggered. Accordingly, the second recessed grooves 13 eliminate the direct spray pattern caused by the first recessed grooves 12 in the area adjacent to the light incident surface 10, and the first recessed grooves 12 eliminate the second recessed grooves 13. The staggering phenomenon caused by the light incident surface 10 adjacent to the light incident surface further improves the uniformity of the light output of the light emitting surface 11 of the light guide plate 1 and eliminates the appearance of light distribution with uneven brightness distribution. The first recessed trench 12 and the second recessed trench 13 are both formed by extrusion. In addition to improving the process efficiency and reducing the time cost of production, the extrusion molding method is also more conducive to making the first recessed trench. 12 and the second recessed groove 13 are large-sized thin light guide plates, which provide products that meet market demands. The detailed manufacturing steps of the light guide plate are described in the following embodiments. To reiterate, the present invention is a first recessed groove 12 having a light-receiving surface 11 of the light guide plate 1 that is recessed and has a different depth. And the second recessed groove 13 and the first recessed groove 12 and the second recessed groove 13 are respectively within the aforementioned range of depth values, which can help eliminate the uneven brightness and dark phenomenon of the aforementioned staggered pattern and direct spray pattern, While improving the overall light output luminance of the light guide plate 1, the light uniformity of the light guide plate 1 is ensured. In addition, the first recessed trench 12 and the second recessed trench 13 are recessed structures and are formed in an extrusion manner, which is different from the conventional light guide plate using injection molding to form a convex microstructure technology, which effectively improves the process efficiency And the product yield, and the light guide plate 1 made by the first recessed groove 12 and the second recessed groove 13 staggered in depth, effectively eliminates the direct spray pattern and staggered pattern that affect the uniformity of light output.

In this embodiment, the first recessed trenches 12 and the second recessed trenches 13 are continuously adjacent to each other, as shown in FIG. 1 and FIG. 2, in order to achieve better light output efficiency according to some requirements. In addition, the first recessed trenches 12 and the second recessed trenches 13 may be V-shaped or arc-shaped. Here, the first recessed trenches 12 and the second recessed trenches 13 are V-shaped. The structure has two groove slopes 14, 15 as an example, and the angle α sandwiched by the groove slopes 14, 15 is preferably between 70 and 90 degrees. This is to avoid the occurrence of bright lines or streaks caused by the angle α being too large, and the effect of increasing the brightness of the light emitted when the angle α is too small, thereby enabling the light guide plate 1 to have a better light guiding effect on light.

Please refer to FIG. 3 and FIG. 4 together, which are schematic plan views of the light guide plate in another implementation state of the preferred embodiment of the present invention and planar view of the light guide plate in another implementation state. In addition to the first recessed trenches 12 and the second recessed trenches 13, as shown in FIGS. 1 and 2, the first recessed trenches 12 and the second recessed trenches 13 may be connected and arranged adjacent to each other. The two recessed trenches 13 may be correspondingly set to other structural states. For example, as shown in FIG. 3, the first recessed trenches 12 and the second recessed trenches 13 may be arranged at intervals, and any one of the first recessed trenches 12 and the second recessed trenches 13 adjacent to each other. The system is flat. According to this, the light guide plate 1 can also be used to eliminate the proximity by the first recessed groove 12 and the second recessed groove 13 when the light is emitted. The direct spray pattern and staggered pattern on the light incident surface are effective to improve the light output brightness of the light guide plate 1 and increase the light uniformity.

Of course, the first recessed trenches 12 and the second recessed trenches 13 may also be arc-shaped recessed structures, as shown in FIG. 4, and may also be continuously adjacent or spaced apart. In this structure state, the first recessed grooves 12 and the second recessed grooves 13 can also achieve the effect of eliminating staggered patterns and direct spray patterns.

Please refer to FIGS. 5 and 6, which are flow charts of the method for manufacturing the light guide plate and the schematic diagram of the application of the printing roller according to the preferred embodiment of the present invention, and refer to FIGS. 1 and 2 together. The invention also discloses a method for manufacturing a light guide plate with high light uniformity, which includes the following steps.

First, a light guide plate 1 is provided. The light guide plate 1 has a light entrance surface 10 and a light exit surface 11, and the light exit surface 11 is vertically adjacent to the light entrance surface 10 (step S01). Then, a printing roller 2 is provided. The printing roller 2 has a plurality of first protruding ribs 20 and a plurality of second protruding ribs 21. The first protruding ribs 20 are pushed into the light guide plate 1 with a first height of 50 to 90 μm, and the second protruding ribs. 21 is pushed into the light guide plate 1 with a second height of 10-30 μm, and the first convex ribs 20 and the second convex ribs 21 are staggered (step S02). Subsequently, a plurality of first recessed grooves 12 and a plurality of second recessed grooves 13 are formed by printing on the light-emitting surface 11 of the light guide plate 1. The first recessed grooves 12 have a first depth A of 50 to 90 μm, and a second recessed grooves. 13 has a second depth B of 10-30 μm, and the first recessed trenches 12 and the second recessed trenches 13 are staggered (step S03). Among them, it is preferable that the aforementioned light guide plate 1 can be a plastic substrate, and can be formed into a light guide plate having a desired thickness through a pre-operation, and the post-pressing printing roller 2 is printed on the light-emitting surface 11 to form the aforementioned first depression. The grooves 12 and the second recessed grooves 13 and the light guide plate 1 can be cut to the required size after the first recessed grooves 12 and the second recessed grooves 13 are formed, or cut to The required size can be processed again. In this way, the first recessed grooves 12 and the second recessed grooves 13 are formed by printing on the light-emitting surface 11 of the light guide plate 1 through the printing roller 2. In a single press printing process, the first recessed trench 12 and the second recessed trench 13 with two different depths can be formed, thereby greatly improving the process speed. And the process method can directly emboss the thin light guide plate, which can improve the product yield and process rate of the large size thin light guide plate. Among them, the structure depicted in the figure is provided for the purpose of explanation and illustration, in order to facilitate understanding of the aforementioned manufacturing method steps, and does not represent the actual structure size ratio.

The first protruding ribs 20 and the second protruding ribs 21 may be continuously adjacent to each other, or may be arranged at intervals. Here, the first protruding ribs 20 and the second protruding ribs 21 are consecutively adjacent to each other as an example, as shown in FIG. 6. Show. According to this, after the light-emitting surface 11 of the light guide plate 1 is embossed by the printing roller 2, the first concave grooves 12 and the second concave grooves 13 can be formed on the light-emitting surface 11 to be continuously adjacent to each other. In addition, the first raised ribs 20 and the second raised ribs 21 may be V-shaped or arc-shaped structures. When the first raised ribs 20 and the second raised ribs 21 are V-shaped structures, they have two raised rib slopes 22 and 23, respectively. And the angle β sandwiched by the convex rib slopes 22 and 23 is between 70 and 90 degrees. Thereby, the first recessed groove 12 and the second recessed groove 13 formed into a V-shaped structure can be printed on the light exit surface 11 of the light guide plate 1 through the printing roller 2, and the first recessed groove 12 and the second recessed groove The grooves 13 respectively have two groove inclined surfaces 14, and an included angle α of the groove inclined surfaces 14 is between 70 and 90 degrees. Among them, for the structure of the light guide plate 1 made through the foregoing steps, please refer to the contents shown in FIGS. 1 and 2 again.

Please refer to FIG. 7 together, which is a schematic diagram of the application of the press roller in another implementation state of the preferred embodiment of the present invention, and refer to FIG. 3 for matching. As mentioned above, the first convex ribs 20 and the second convex ribs 21 may also be arranged at intervals. When the first convex ribs 20 and the second convex ribs 21 are spaced apart from each other, a planar structure is formed between them. Referring to Figures 7 and 3, in this structure, when the printing roller 2 is printed on the light-emitting surface 11 of the light guide plate 1, the light-receiving surface 11 can be formed into a first recessed groove 12 and a second recessed groove arranged at intervals. The trench 13 is a planar structure between any one of the adjacent first recessed trenches 12 and the second recessed trenches 13, as shown in FIG. 3.

In summary, the light guide plate with high light emission uniformity and the manufacturing method thereof of the present invention can eliminate the phenomenon of direct spraying or staggering caused when a recessed groove is provided to improve the overall light output, thereby ensuring the The overall light output of the light guide plate is uniform to prevent the problem of uneven light. In addition, through extrusion printing, in addition to improving the product processing speed, it also solves the problem of difficult to apply large-sized thin light guide plates, and provides more excellent optical products that meet market demand.

Claims (7)

A light guide plate with high light emitting uniformity has a light incident surface and a light emitting surface. The light incident surface is used to receive light from a light source. The light emitting surface is vertically adjacent to the light incident surface and includes a plurality of first recessed grooves. A groove is extruded and formed on the light emitting surface and has a first depth of 50 to 90 μm; and a plurality of second recessed grooves is extruded and formed on the light emitting surface and has a second depth of 10 to 30 μm, and is the same as the first The recessed grooves are staggered; wherein the first recessed grooves and the second recessed grooves are V-shaped and have two groove slopes, and the angles between the groove slopes are between 70 and 90 degrees; Accordingly, the second recessed grooves eliminate the direct spray pattern caused by the first recessed grooves adjacent to the light incident area, and the first recessed grooves eliminate the second recessed grooves. The streaks caused by the area adjacent to the light incident surface. The light guide plate with high light uniformity as described in item 1 of the scope of the patent application, wherein the first recessed grooves and the second recessed grooves are continuously adjacent to each other. The light guide plate with high light uniformity as described in item 1 of the scope of the patent application, wherein the first recessed grooves and the second recessed grooves are spaced apart, and any one of the adjacent ones of the first A plane is formed between the recessed trench and the second recessed trench. A manufacturing method for manufacturing a light guide plate with high light uniformity includes the following steps: providing a light guide plate having a light incident surface and a light emitting surface, and the light emitting surface is vertically adjacent to the light incident surface. ; Provide a printing roller, the printing roller has a plurality of first ribs and a plurality of second ribs, the first ribs are pressed into the light guide plate with a first height of 50 ~ 90 μm, the second ribs are A second height of 10-30 μm is pushed into the light guide plate, and the first ribs and the second ribs are staggered; and a plurality of first recessed grooves are stamped on the light emitting surface of the light guide plate and A plurality of second recessed trenches, the first recessed trenches have a first depth of 50 to 90 μm, the second recessed trenches have a second depth of 10 to 30 μm, and the first recessed trenches and The second recessed trenches are staggered. According to the method for manufacturing a light guide plate with high uniformity of light emission as described in item 4 of the scope of patent application, wherein the first convex ribs and the second convex ribs are continuously arranged adjacently. The method for manufacturing a light guide plate with high uniformity of light emission as described in item 4 of the scope of the patent application, wherein the first ribs and the second ribs are spaced apart and adjacent to each other. A plane is formed between any of the first ribs and the second ribs. The manufacturing method for making a light guide plate with high light uniformity as described in item 4 of the scope of the patent application, wherein the first convex ribs and the second convex ribs are V-shaped and have two convex rib inclined surfaces. The angle between the inclined surfaces of the ribs is between 70 and 90 degrees.