TWI695216B - Light guide plate with high brightness and high light entrance angle and manufacturing method of backlight module - Google Patents

Abstract

Light guide plate with high brightness and high light entrance angle and manufacturing method of backlight module are disclosed. A plurality of light guiding grooves on the light emitting surface of the light guide plate body and a plurality of light-expanding microstructure on the light incident surface of the light guide plate body are formed on the light guide plate body which has a thickness of 1.5 to 2.5 mm by imprinting. The light incident surface is provided for receiving the light of the LED light source; the distance from the LED light source is maintained at 0.25 to 0.45mm, and the distance between any adjacent LED light sources is 19.5 to 19.9mm. Each of the light-expanding microstructure is a convex column and arranged continuously, and the cross section of the light-expanding microstructure has a curved arc at the top and a straight section on both sides of the bottom. The light-expanding microstructure is distributed upwardly from lower edge of the light incident surface and occupies 13 to 23% of the area of the light incident surface, the protruding length of the light-expanding microstructure is between 27 to 33μm, the spacing between any two adjacent curved segments is between 70 to 76μm, and the angle between any two adjacent oblique straight sections is between 46 to 66 degrees. The light emitting surface has a transition zone with a length of 5.5 to 6.5mm, the depth of the light guiding groove is between 38 to 42μm, and the distance between the two adjacent light guiding grooves is between 270 to 330μm. In this way, it can effectively improve the taste of light when applied.

Description

Manufacturing method of light guide plate and backlight module having both high brightness and high incident angle

The present invention is related to the field of optical components, in particular to a method for manufacturing a light guide plate and a backlight module with both high brightness and high incident angle.

The light guide plate is one of the most important products in the field of optical components. It has excellent light guide performance and can convert the light guide of the point light source into a full-face light for use as a light source. Lighting fixtures and display devices are a large selection of applications.

In general, the main considerations for the design of the light guide plate are the brightness and uniformity. In order to improve the aforementioned light appearance and taste, the current method adopted by the relevant manufacturers is to set various microstructures on the light guide plate to adjust the light in the light guide plate. The state of conduction and light emission. The specific production of light guide plates is mostly made by injection molding. In order to form the aforementioned microstructures on the light guide plate, the corresponding microstructures need to be depicted on the mold by means such as cutting with a cutter, so that the light guide plate forms these structures on it when it is emitted. However, the quality of the light guide plate made in this way and its microstructure are not good, and it is easy to produce structural shapes that are different from expectations, and injection molding is also not suitable for making large-size light guide plates. On the other hand, there is also a method of cutting the light guide plate with a tool to make a microstructure, but this method is prone to produce residual dust after production, and these residual dusts have considerable disadvantages for the light guide system Impact, and tool cutting is also not suitable for making large-size light guide plates, and its efficiency and yield have great shortcomings.

Moreover, when a variety of microstructures are provided on the light guide plate, it is relatively easy to cause the sensitive light to be guided to form an unexpected light state, and many phenomena that affect the light uniformity and brightness are generated. Therefore, how to effectively improve the light-emitting taste of the light guide plate so that the modules and devices equipped with the application have better light-emitting performance is a problem that needs to be overcome and solved in related industries.

In view of this, an object of the present invention is to provide a method for manufacturing a light guide plate and a backlight module having both high brightness and high light incident angle, which can eliminate the light interference phenomenon caused by the structure on the light guide plate , Significantly improve the light taste of the light guide plate when it is applied, and have excellent production speed and product yield on the application requirements of large size.

In order to achieve the above object, in one embodiment of the present invention, a light guide plate with both high brightness and high light incident angle is provided for receiving light from a plurality of LED light sources, including: a light guide plate body with a thickness of 1.5-2.5 mm, with a light incident surface and a light exit surface, the light exit surface and the light incident surface are vertically adjacent for light output, the distance between the light incident surface and the LED light sources is maintained at 0.25 ~ 0.45mm, any two adjacent The distance between the LED light sources is 19.5～19.9mm; the multiple spreading microstructures are formed on the light incident surface by rolling and are arranged continuously, each of the spreading microstructures are convex columns, and the cross section is the top It has a curved arc section and a shape of an oblique straight section on both sides of the bottom; wherein each of the light-expanding microstructures is distributed upward from the lower edge of the light incident surface, accounting for 13 to 23% of the area of the light incident surface The projection length of each of the light-expanding microstructures is between 27 and 33 μm, the distance between any two adjacent curved segments is between 70 and 76 μm, and the angle between any two adjacent straight segments is between At 46-66 degrees; a transition zone located on the light exit surface and extending from the upper edge of the light entrance surface away from the light entrance surface, with an extension length of 5.5-6.5 mm; and a plurality of light guide grooves, which It is a V-shaped structure distributed on the light exit surface by means of extrusion molding. The depth of each light guide groove is 38-42 μm, and the distance between any two adjacent light guide grooves is 270~ 330μm. In this way, the interference phenomenon generated when the light is guided by the light guide plate can be effectively eliminated, so as to greatly improve the optical taste of the light guide plate when it is applied.

In one embodiment of the present invention, a method for manufacturing a backlight module having both high brightness and high light incident angle is provided, which includes the following steps: providing a light guide plate having a light incident surface and a light exit surface And a transition area, and the thickness of the light guide plate is between 1.5 and 2.5 mm, wherein the light entrance surface and the light exit surface are vertically adjacent to each other, the transition area is located on the light exit surface, and faces from the upper edge of the light entrance surface Extending away from the direction of the light entrance surface, the extension length is 5.5-6.5mm; multiple light guide grooves are imprinted on the light exit surface, wherein the light guide grooves are respectively V-shaped structures, and the depth of each light guide groove Between 38-42 μm, and the distance between any two adjacent light-guiding trenches is between 270-330 μm; a plurality of light-expanding microstructures are embossed on the light-incident surface, wherein the light-spreading microstructures are from the entrance The lower edge of the light surface is distributed upwards and arranged continuously, each of the light-expanding microstructures is convex column-shaped, and the cross-section of each light-expanding microstructure is a curved arc segment at the top and a diagonal straight on both sides of the bottom The shape of the segment; wherein each of the light-expanding microstructures accounts for 13 to 23% of the area of the light incident surface, the protrusion length of each light-expanding microstructure is between 27 and 33 μm, and any two adjacent arcs The distance between the segments is between 70 and 76 μm, and the angle between any two adjacent straight segments is between 46 and 66 degrees; and a plurality of LED light sources are arranged on the light incident surface, and the LED light sources and the incident light are The distance between the surfaces is maintained at 0.25 to 0.45 mm, and the distance between any two adjacent LED light sources is between 19.5 to 19.9 mm. The backlight module manufactured through the foregoing steps has excellent light uniformity and brightness, which effectively improves the overall light taste.

Based on the foregoing two embodiments, in yet another embodiment, the thickness of the light guide plate body is further disclosed to be 2.2 mm, so as to have better application performance.

In the next embodiment, the protruding length of each of the spreading microstructures is 30 μm, the distance between any two adjacent curved segments is 73 μm, and the angle between any two adjacent straight segments is It is between 54-57 degrees, which can make the light guide plate have a better light spreading effect.

In one embodiment, it is disclosed that the depth of the light guide groove is 40 μm, and the distance between any two adjacent light guide grooves is 300 μm, so as to have better brightness adjustment performance.

In order to make the light have a better incident state, in order to facilitate the light guide plate to smoothly adjust to the incident light, in one embodiment, it is disclosed that the distance between the LED light sources and the light incident surface is 0.35mm, any two adjacent The distance between the LED light sources is 19.7mm.

In summary, the manufacturing method of the light guide plate and the backlight module with high brightness and high incident angle disclosed in the present invention reveals that the structure formed by the limitation of a specific ruler makes the light guide plate also have high light output Brightness and high incident light angle eliminate the optical interference phenomenon when two structures coexist in the light guide plate, greatly improve the light taste of the light guide plate, and provide higher-order and high-quality optical products. In view of the fact that it is not easy to produce large-size light guide plates today, the light guide plates disclosed in the present invention are made by pressing out to make the light-expanding microstructures and light guide grooves, which can solve the past use of injection molding or tool cutting cannot be applied to The problem of making large-size light guide plates.

Since the development and design technology of the light guide plate has evolved, the relevant manufacturers have basically possessed quite skilled design capabilities. Based on the application of the light guide plate and the differences in the environmental components, the light output requirements of the light guide plate may be slightly different, such as for display devices The light guide plate in the field has relatively strict requirements on the uniformity of light output, while the light guide plate applied in the lighting field may have requirements on the distribution state of the light intensity. Taking the light guide plate in the display device as an example, in order to make the mounted display panel have better display presentation, the light uniformity and brightness of the light guide plate itself are the most important design considerations and improvement goals.

At present, the common reason that affects the uniformity of the light output of the light guide plate is the uneven brightness and darkness caused by the point light source, also known as the hot spot phenomenon, which is caused by the excessive concentration and collimation of the light projected by the point light source onto the light guide plate. Adjacent point light sources are interposed to form a relatively dark area, so that the light guide plate adjacent to the side receiving the light forms the hot spot phenomenon as described above. The hot spot phenomenon of uneven light and dark will make the light guide plate appear significant bright spots during application, so that the provided surface light source is not uniform enough to affect the display performance of the display device. In order to solve the hot spot phenomenon of uneven brightness, the more intuitive and quick solution is to eliminate the dark areas formed between the point light sources as much as possible, while allowing the light guide plate to correspond to the area of the main optical axis of the point light source and other areas. The brightness is more consistent. The feasible solution is to increase the number of point light sources to fill the dark area with the light provided by more point light sources; or to set up microstructures on the light guide plate to adjust the incident angle of the point light source and expand the adjacent light source. The overlapping area of the incident light from the point light source eliminates the occurrence of bright and dark areas; or increase the distance between the point light source and the light incident surface to increase the incident angle of the light incident on the light guide plate. However, the method of increasing the number of point light sources, in addition to increasing the manufacturing cost, is also likely to cause local over-brightness due to the excessive overlap of the light output. The solution of extending the distance between the point light source and the light incident surface will cause an increase in volume and light output. Efficiency drops. Therefore, in addition to responding to special purposes, most of them still adopt the method of setting microstructures on the light guide plate to solve the hot spot phenomenon. In general, the preferred embodiment is to provide microstructures on the light incident surface of the light guide plate, thereby expanding the spread angle of the light from the point light source when entering the light guide plate.

The light output brightness guides the positive light output brightness of the light plate. Since the light enters the light guide plate, it is affected by the continuous light guide travel, and the light energy that can form the light output on the light output surface has almost been exhausted, and the light output brightness is not enough. This will greatly affect the display performance when the light guide plate is applied to a display device. In order to allow the light to be guided by the light guide plate and emit light from the front surface, it can have higher light energy, and even if the brightness of the light is effectively improved, at present, the method of providing grooves on the surface of the light guide plate is adopted to make part of the light guide plate enter the light guide plate. The light is refracted to achieve the purpose of enhancing the brightness.

The above-mentioned microstructure and groove design, in the past light guide plate design concept, have less application to install it on the light guide plate at the same time, most of the current relevant manufacturers will only choose one for production, so it can only be solved The single optics is missing, but as the market requirements for related products change, the high-level light guide plates and backlight modules require high specifications. The team of the present invention began to conceive and develop this aspect. However, the team of the present invention found that when the light guide plate has both the microstructure of the light incident surface and the grooves on the surface, the incident light is affected by the microstructure and the spread angle is increased, which was originally able to solve the hot spot phenomenon of uneven brightness However, after the light continued to touch the groove, the spread angle was too large because of the refraction of the groove, resulting in too dark in front of the point light source, but a bright packet between the point light sources, which caused serious light interference problems As shown in Figures 7A and 7B, it can be seen from the figure that the light distribution of the light guide plate obviously has extremely bright areas or bright spots.

As mentioned above, when the microstructure and the groove are present on the light guide plate at the same time, serious interference will occur. In order to eliminate these factors, the team of the present invention has designed and experimented on various elements that will affect the light guiding and light emitting state one by one. These requirements that affect the light guiding and light emitting state, specifically include the size of the light guide plate itself, the state of the point light source used for the application, the size and position of the microstructure, the size and position of the groove, etc. After continuous matching experiments, a better overall structure and surrounding conditions are obtained, which is the specific technical content proposed by the present invention.

Please refer to FIGS. 1 to 3, which are a three-dimensional schematic diagram of the light guide plate, a partial cross-sectional schematic diagram of the light guide plate and an assembly schematic diagram of the light guide plate and the LED light source according to the preferred embodiment of the present invention. Please also refer to Figures 8A-11, which are schematic diagrams of the optical verification results and corresponding schematic diagrams performed by the present invention. Based on the requirements of thinness and large size required by the current market, the light guide plate 1 disclosed herein which has both high brightness and high light entrance angle is used to receive light from a plurality of LED light sources 2, including a light guide plate The body 10, the plurality of light spreading microstructures 11, a transition area 12 and the plurality of light guide grooves 13 are provided. The thickness T of the light guide plate body 10 is between 1.5 and 2.5 mm, and has a light incident surface 101 and a light exit surface 102. The light exit surface 102 and the light entrance surface 101 are vertically adjacent for light output. The light entrance surface 101 and the LED light source 2 The distance A is maintained at 0.25 to 0.45 mm, and the distance P ₁ between any two adjacent LED light sources 2 is 19.5 to 19.9 mm. The light-expanding microstructures 11 are formed on the light-incident surface 101 by rolling and are continuously arranged. Each light-expanding microstructure 11 is in the shape of a convex column, and its cross section is a curved arc segment 111 at the top, and one at each side of the bottom. The shape of the oblique straight section 112. Each of the light-expanding microstructures 11 is distributed upward from the lower edge of the light incident surface 101 and accounts for 13 to 23% of the area of the light-incident surface 101. The protrusion length L ₁ of each light-expanding microstructure 11 is between 27 and 33 μm. The distance P ₂ between any two adjacent curved arc segments 111 is between 70 and 76 μm, and the angle θ between any two adjacent oblique straight segments 112 is between 46 and 66 degrees. The light-spreading microstructure 11 extends along the long side of the light incident surface 101, and the length of its layout is equal to the length of the long side of the light incident surface 101, but it is not completely spread in the short side direction of the light incident surface 101. The status is shown in Figure 1. The transition region 12 is located on the light exit surface 102 and extends from the upper edge of the light entrance surface 101 in a direction away from the light entrance surface 101, and its extension length L ₂ is 5.5-6.5 mm. The transition area 12 is defined here as a non-visible area on the light-emitting surface 102. When the light guide plate 1 is combined with other components to form a display device, the area may be covered by the frame and not belong to the viewing area of the user. The light guide grooves 13 are distributed on the light emitting surface 102 by a press molding method and have a V-shaped structure. The depth D of each light guide groove 13 is between 38 and 42 μm, and any two adjacent light guide grooves The distance P ₃ between 13 is between 270 and 330 μm. In this way, the optical interference caused by the groove and the microstructure on the light guide plate 1 can be effectively eliminated, and the optical taste during application can be improved. Among them, the dimensions and proportions of the elements drawn in the drawings are to clearly illustrate the structure and relative relationship of the present invention, so as to understand the technical features of the present invention, and do not represent the actual size ratios. Mainly recorded.

In view of the large size and thin product requirements, the thickness of the light guide plate body 10 of the present invention is limited to 1.5-2.5 mm. A preferred embodiment is that the thickness T of the light guide plate body 10 is 2.2 mm. Under the aforementioned thickness conditions, the light spreading microstructure 11 and the light guiding groove 13 are designed and simulated. Among them, in order to improve the production speed and yield, and is more suitable for the production of large-size light guide plates, the light spreading microstructures 11 and the light guide grooves 13 on the light guide plate body 10 of the present invention are all made by rolling imprinting. Forming, the selection of rolling method can help to quickly and accurately form the light-expanding microstructure 11 and the light guide groove 13 of the special shape and gauge on the light guide plate body 10, thus effectively solving the past injection molding or tool cutting The resulting yield rate is low and production difficulties and other problems, the remaining detailed manufacturing steps are further explained in the subsequent manufacturing method

Regarding the light-expanding microstructures 11, the cross-section of the light-expanding microstructure 11 is a curved arc section 111 and two oblique straight sections 112, so that the light spreading angle of the light from the LED light source 2 entering the light guide plate 1 can be expanded and pass through the aforementioned The size of the ruler allows the light guide plate 1 to increase the incident angle of light while avoiding the interference of light. A preferred implementation state is that the protruding length L ₁ of each spreading microstructure 11 is 30 μm, the distance P ₂ between any two adjacent curved arc segments 111 is 73 μm, and any two adjacent oblique straight segments 112 are The angle θ of the clip is between 54 and 57 degrees, so as to have more excellent effects of dimming and avoiding light interference. In particular, the light-spreading microstructures 11 of the present invention are arranged from the lower edge of the light incident surface 101 upwards, and occupy 13 to 23% of the area of the light incident surface 101, rather than spread all over the light incident surface 101. The reason for this is that when the spreading microstructure 11 is spread over the light incident surface 101, when the light is guided by the spreading microstructure 11 and the light guiding groove 13, an excessive angle of spread will be generated, which will result in bright packets. Therefore, the preliminary concept excludes the design that spreads the light-expanding microstructure 11 all over the light incident surface 101. Then, it is necessary to consider the state in which the light spreading microstructure 11 is distributed on the light incident surface. For this, the team of the present invention uses the light guide plate 1 having the foregoing parameters as a verification basis for the light spreading microstructure 11 The optical performance when forming on different areas of the light incident surface is tested. The test results are shown in Figures 8A and 8B, where (a) in Figure 8A represents the spreading microstructure 11 located in the area above the light incident surface 101 The light intensity distribution diagram of Fig. 8A (b) represents the light intensity distribution diagram of the abundance microstructure 11 located in the central area of the light incident surface 101, and (c) of Fig. 8A represents the abundance microstructure 11 located at Light intensity distribution diagram of the area below the light incident surface 101; (a) in Figure 8B shows the light spreading state when the light-expanding microstructure 11 is located in the area above the light incident surface 101, and (b) in Figure 8B shows the light spreading The light spreading state when the light microstructure 11 is located in the central region of the light incident surface 101, (c) in FIG. 8B shows the light spreading state when the light spreading microstructure 11 is located in the region below the light incident surface 101. According to the results, it is found that when the light spreading microstructure 11 is located in the central area of the light incident surface 101, although it has the best light spreading effect, some light will be emitted directly from the visible area behind the adjacent transition area 12, resulting in a localized visible area. The bright spot makes the optical taste relatively inferior, and the rolling process needs to use one side of the light guide plate 1 as the positioning point for imprinting. Therefore, the centered light-expanding microstructure 11 is very difficult to manufacture. According to this, there is a choice for distributing the light-expanding microstructure 11 to the area below the light-incident surface 101 or the area above the light-incident surface 101. As can be seen from the figure, the light-spreading microstructure 11 is distributed under the light-incident surface 101 Better optical taste, will not let local light exit from the non-transition zone 12, a frame mask is generally provided above the transition zone 12 to conceal the flaw, but the mask is expected to be small to achieve a narrow border; and distributed above the light incident surface 101 It is easy to produce bright packets with a large viewing angle, which is why the light-spreading microstructures 11 disclosed by the present invention are distributed upward from the lower edge of the light incident surface 101. The next step is to determine the size of the distribution area of the abundance microstructure 11. In this regard, the team of the present invention also detects the light-out state of the abundance microstructure 11 at various percentages of the area of the light entrance 101. Here, the light guide plate body 10 with a thickness of 2.2 mm is used, and the lower edge of the light incident surface 101 is used as a reference line, so that the height of the light-expanding microstructure 11 is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, respectively. , 0.8, 0.9 and 1mm, the light output status is shown in Figure 9. As can be seen from the figure, when the percentage of the light-expanding microstructure 11 to the area of the light-entering surface 101 is less than 13%, that is, the height of the light-expanding microstructure 11 is less than 0.3 mm, a bright area will be generated in front of the LED light source 2, when it is greater than 23 %, that is, when the height of the spreading microstructure 11 is greater than 0.5 mm, a bright area will be generated between the adjacent LED light sources 2, and both conditions will affect the light emitting taste of the light guide plate 1. Therefore, when the spreading microstructure 11 occupies 13% to 23% of the area of the light incident surface 101, it has the best light taste presentation. This is the limitation of the present invention to limit the spreading microstructure 11 to 13% of the area of the light incident surface 101. ~23%.

Regarding the part of the light guide groove 13, it is transmitted through the V-shaped structure, and the effective refracted part enters the light guide plate 1 through the light entrance surface 101 and the spreading microstructure 11 thereon, so that the overall light output surface 102 has a brightness It has been improved, and the light guide plate 1 can enhance the brightness while avoiding the interference of light through the aforementioned rule limit. Further, in order to have better optical adjustment performance and light output, a preferred implementation state is to make the depth D of each light guide groove 13 40 μm, and the distance P ₃ between any two adjacent light guide grooves 13 is 300 μm.

Further, due to the setting conditions of the LED light source 2 used in conjunction with the light guide plate 1, it will also have a great influence on the subsequent overall light output of the light guide plate 1, so in addition to obtaining the better structure restrictions of the light guide plate 1, the LED light source 2 The setting requirements of the present invention have also been verified accordingly. First, the distance A between the LED light source 2 and the light incident surface 101 is limited. The distance A between the LED light source 2 and the light incident surface 101 is generally referred to as Air Gap in the related art. As described above for the hot spot phenomenon, when the distance between the LED light source 2 and the light incident surface 101 is too far, the incident light intensity will be insufficient and the light output efficiency will be poor. Therefore, the LED light source 2 must not be too far away from the light incident surface 101. Relatively, the LED light source 2 should not be too close to the light incident surface 101 to avoid the phenomenon of bright spots and bright packets in front of the LED light edge 2. The present invention is directed to the difference between the LED light source 2 and the light incident surface 101 at different distances The light performance is verified, as shown in Figure 10 and Table 1 below. It can be seen from the figure that when the distance A between the LED light source 2 and the light incident surface 101 is less than 0.25mm, there will be obvious bright lines. Then, when the distance A between the LED light source 2 and the light incident surface 101 is less than 0.35mm, it only starts to appear The fine bright lines fall within the acceptable optical taste range, and when the distance A between the LED light source 2 and the light incident surface 101 is greater than or equal to 0.35 mm, the visual effect begins to be smoother, although the LED light source 2 and the light incident surface 101 When the distance A comes to 0.5mm, the visual effect is also in a smooth state, but according to the content of Table 1, it is found that the average light surface brightness is too low. Therefore, the light guide plate 1 disclosed in the present invention is equipped with an LED light source 2 In application, the distance between the light incident surface 101 and the LED light source 2 must be kept within a range of 0.25 to 0.45 mm. Further considering the average brightness of the light emitting surface 102, a preferred implementation state is that the distance A between the LED light source 2 and the light incident surface 101 is 0.35 mm, so that both the brightness and the optical taste can be considered. Air Gap(mm) 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 Average surface brightness (nits) 1886 1861 1835 1798 1763 1726 1692 1656 1623 109% 108% 106% 104% 102% 100% 98% 96% 94% Table I

In addition to the distance between the LED light source 2 and the light incident surface 101 will affect the light output when the light guide plate 1 is applied, the distance between the LED light sources 2 and the length of the transition area 12 on the light guide plate 1 will also be affected. The pitch P ₁ , the team of the present invention has used the light guide plate 1 with the aforementioned parameters as the basis for verification, and found that when the distance P ₁ between the LED light sources 2 is 19.5 to 19.9 mm, it can have a better light taste. When the LED light source When the distance P ₁ between _{2 does} not fall within the aforementioned range, the hot spot phenomenon will be relatively serious, and a preferred implementation state is that the distance P ₁ between any two adjacent LED light sources 2 is 19.7 mm. Successively, the team of the present invention verified that the distance P ₁ between any two adjacent LED light sources 2 was 19.7 mm. As shown in FIG. 11, it can be seen that when the extension length L _{2 of the} transition zone 12 is between 5.5 and 6.5 mm, it will not A hot spot phenomenon occurs, but as the extension length L ₂ of the transition zone 12 decreases, bright and dark areas appear due to the insufficient spread angle of the incident light, and one of the preferred implementation states is to extend the extension length L _{2 of the} transition zone 12 6mm.

Please refer to FIGS. 4-6, which are the steps of the backlight module manufacturing method according to the preferred embodiment of the present invention, the schematic diagram of forming light guide grooves by imprinting, and the schematic diagram of forming light spreading microstructures by imprinting. Please also refer to Figures 1 to 3 and 8A to 11 for details. As shown in the figure, the present invention also discloses a method for manufacturing a backlight module 3 having both high brightness and high incident angle, including the following steps. First, a light guide plate body 10 is provided. The light guide plate body 10 has a light incident surface 101, a light exit surface 102, and a transition area 12, and the thickness T of the light guide plate body 10 is between 1.5 and 2.5 mm, of which the light incident surface 101 The light exit surface 102 is vertically adjacent to each other. The transition area 12 is located on the light exit surface 102 and extends from the upper edge of the light entrance surface 101 in a direction away from the light entrance surface 101, and its extension length L is 5.5-6.5 mm (step S01). Then, a plurality of light guide grooves 13 are imprinted on the light exit surface 102, wherein the light guide grooves 13 are respectively V-shaped structures, the depth D of each light guide groove 13 is between 38 and 42 μm, and any two adjacent light guide grooves The distance between the grooves 13 is between 270 and 330 μm (step S02). Imprinting a plurality of light-expanding microstructures 11 on the light incident surface 101, wherein the light-expanding microstructures 11 are distributed upward from the lower edge of the light incident surface 101 and are continuously arranged, and each light-expanding microstructure 11 is convex and cylindrical, and The cross-section of each light-expanding microstructure 11 is a curved arc section 111 at the top, and an oblique straight section 112 at both sides of the bottom; each of the light-expanding microstructures 11 accounts for 13 to 23% of the area of the incident light surface 101 , The protruding length L ₁ of each spreading microstructure 11 is between 27-33 μm, the distance P ₂ between any two adjacent curved arc segments 112 is between 70-76 μm, and the angle between any two adjacent oblique straight segments 112 θ is between 46 and 66 degrees (step S03). It should be noted that the aforementioned sequence of steps is not intended to limit the sequence of the manufacturing method of the present invention. In fact, when manufacturing the aforementioned backlight module 3, the light guide groove 13 may be imprinted as described above and then pressed. Imprinting the microstructure 11 or imprinting the microstructure 11 first and then imprinting the light guide groove 13 may be used for the sake of illustration, so as to imprint the light guide groove 13 first in the manufacturing sequence. Take the imprinted light-expanding microstructure 11 as an example. After the light guide plate body 10 forms the light guide groove 13 and the light-expanding microstructure 11 through imprinting to form the light guide plate 1 as described above, a plurality of LED light sources 2 are provided on the light incident surface 101, and the LED light sources 2 and The distance A of the light incident surface 101 is maintained at 0.25 to 0.45 mm, and the distance P ₁ between any two adjacent LED light sources 2 is between 19.5 to 19.9 mm (step S04), and the manufacture of the backlight module 3 is completed. In this way, during application, the aforementioned backlight module 3 can eliminate the optical interference phenomenon generated when the light guide plate 1 has the light guide groove 13 and the light spreading microstructure 11 at the same time, and has an excellent light emitting taste, greatly improving the product The quality makes the mounted display device have better display performance.

A preferred embodiment of embossing the light guide groove 13 and the light spreading microstructure 11 is to apply the light on the light entrance surface 101 and the light exit surface 102 by rolling through a roller. As shown in FIG. 5, there are ribs corresponding to the shape of the light guide groove 13 on the surface of the roller, and correspondingly placed at the light exit surface 102 of the light guide plate body 10, and then the roller contacts the light exit surface 102 and rotates to move The light guide groove 13 is formed by embossing on the light emitting surface 102. In specific manufacturing, the light guide plate body 10 can be moved relative to the roller, and the roller maintains the rotary embossing, and the roller can also be embossed in a manner of horizontal displacement while rotating . As shown in FIG. 6, it is a schematic state in which the light-expanding microstructure 11 is imprinted on the light incident surface 101 by using a roller. Here, the roller has ribs corresponding to the shape of the light-expanding microstructure 11 and correspondingly placed on the At the light surface 101, since the light-expanding microstructure 11 disclosed by the present invention is distributed upward from the lower edge of the light incident surface 101 and occupies 13 to 23% of the area of the light incident surface 101, a better roll The pressing scheme can be based on the lower edge of the light incident surface on the roller, and the above-mentioned ribs are arranged in the area surrounded by a certain length after being extended upwards, so that the light incident surface 101 can be surely specified after being imprinted These spreading microstructures 11 are formed within the area. Among them, the structural size ratio shown in each figure is only for the purpose of explaining its structural characteristics and relative position, and the actual ruler is mainly described in the text of the description.

The conditions for the size of the light guide plate body 10, the shape and size of the light spreading microstructure 11 and the light guide groove 13, their setting reasons and related verification instructions have been described in the preceding paragraphs, and will not be repeated here, please For the combination, please refer to the related content and corresponding drawings.

In summary, the manufacturing method of the light guide plate and the backlight module with high brightness and high incident light angle disclosed by the present invention reveals that the structure formed by the limitation of a specific ruler effectively makes the light guide plate have both The high brightness and high incident light angle eliminate the optical interference caused by the two structures coexisting in the light guide plate, which greatly improves the light taste of the light guide plate and provides higher-order and high-quality optical products. In view of the fact that it is not easy to produce large-size light guide plates today, the light guide plates disclosed in the present invention are made by pressing out to make the light-expanding microstructures and light guide grooves, which can solve the past use of injection molding or tool cutting cannot be applied to The problem of making large-size light guide plates.

1: Light guide plate 10: Light guide plate body 101: Light entrance surface 102: Light exit surface 11: Spread light microstructure 111: Curved arc section 112: Oblique straight section 12: Transition zone 13: Light guide groove 2: LED light source 3: Backlight module A: the distance between the light incident surface and the LED light source P ₁ : the distance between any two adjacent LED light sources L ₁ : the protruding length of the spreading microstructure P ₂ : the distance between any two adjacent curved arc segments θ : the angle of the swash sandwiched between any two adjacent straight segments of the L _2: the length of the transition zone extends D: depth of the light guide trenches P _3: pitch of the light guide trenches S01 ~ S04: step

Figure 1 is a schematic perspective view of a light guide plate according to a preferred embodiment of the present invention. Figure 2 is a schematic diagram of the assembly of the light guide plate and LED light source according to the preferred embodiment of the present invention. FIG. 3 is a schematic partial cross-sectional view of a light guide plate according to a preferred embodiment of the present invention. FIG. 4 is a step diagram of a backlight module manufacturing method according to a preferred embodiment of the present invention. FIG. 5 is a schematic diagram of forming a light guide groove by imprinting a preferred embodiment of the present invention. FIG. 6 is a schematic diagram of forming a light-expanding microstructure by imprinting in a preferred embodiment of the present invention. Fig. 7A is a schematic diagram (1) of the light guide plate with light interference phenomenon. FIG. 7B is a schematic diagram (2) of the light guide plate with light interference phenomenon. Fig. 8A is a schematic diagram of light intensity when the light-expanding microstructure is arranged at different positions on the light incident surface. Figure 8B is a schematic diagram of the state of the light spreading when the light spreading microstructure is set at different positions on the light incident surface. Figure 9 is a schematic diagram of the light-emitting state when the light-expanding microstructure has different heights. Figure 10 is a schematic diagram of the light output state of the LED light source and the light incident surface at different distances Figure 11 is a schematic diagram of the light-out state when the transition zone has different extension lengths.

1: light guide plate

10: Light guide plate body

101: light side

102: light side

11: Exhibition light microstructure

12: Transition area

13: Light guide groove

D: Depth of light guide groove

P ₃ : distance between light guide grooves

Claims (10)

A light guide plate with both high luminosity and high light incident angle for receiving light from a plurality of LED light sources, including: a light guide plate body with a thickness of 1.5~2.5mm, having a light incident surface and a light exit surface, the The light exit surface is vertically adjacent to the light entrance surface for light output. The distance between the light entrance surface and the LED light sources is maintained at 0.25~0.45mm, and the distance between any two adjacent LED light sources is 19.5~19.9mm; The light microstructures are formed on the light incident surface by rolling and are continuously arranged. Each of the light-expanding microstructures is convex column-shaped, and its cross section is a curved arc section at the top, and a slope at both sides of the bottom The shape of the straight section; wherein, each of the light-expanding microstructures is distributed upward from the lower edge of the light incident surface, accounting for 13~23% of the area of the light-incident surface, and the protrusion length of each light-expanding microstructure is between 27~33μm, the distance between any two adjacent curved sections is between 70~76μm, the angle between any two adjacent straight sections is between 46~66 degrees; a transition zone is located in the light exit Surface, and extending from the upper edge of the light incident surface away from the light incident surface, with an extension length of 5.5~6.5mm; and a plurality of light guide grooves, which are distributed on the light exit surface by means of extrusion molding and For the V-shaped structure, the depth of each of the light guide grooves is between 38 and 42 μm, and the distance between any two adjacent light guide grooves is between 270 and 330 μm. As described in item 1 of the patent application scope, a light guide plate having both high brightness and high light incident angle, wherein the thickness of the light guide plate body is 2.2 mm. As described in item 1 of the patent application scope, a light guide plate with both high brightness and high light entrance angle, wherein the protruding length of each of the light exposure microstructures is 30 μm, and any two adjacent arc sections The distance between them is 73μm, and the angle between any two adjacent straight sections is between 54 and 57 degrees. As described in item 1 of the patent application scope, a light guide plate having both high brightness and high light entrance angle, wherein the depth of the light guide groove is 40 μm, and any two adjacent light guide grooves The pitch is 300 μm. As described in item 1 of the patent application scope, a light guide plate with both high brightness and high light incident angle, wherein the distance between the LED light sources and the light incident surface is 0.35mm, and any two adjacent LEDs The distance between the light sources is 19.7mm. A method for manufacturing a backlight module having both high brightness and high light incident angle includes the following steps: providing a light guide plate body, the light guide plate body having a light incident surface, a light exit surface and a transition area, and the The thickness of the light guide plate body is between 1.5 and 2.5 mm, wherein the light incident surface and the light exit surface are vertically adjacent to each other, and the transition area is located on the light exit surface, and away from the light entrance surface from the upper edge of the light entrance surface The direction extends, the extension length is 5.5~6.5mm; multiple light guide grooves are imprinted on the light exit surface, wherein the light guide grooves are respectively V-shaped structures, and the depth of each light guide groove is between 38~42μm, And the distance between any two adjacent light guiding grooves is between 270 and 330 μm; a plurality of light spreading microstructures are imprinted on the light incident surface, wherein the light spreading microstructures are directed from the lower edge of the light incident surface It is distributed and arranged continuously on the top, and each of the light-expanding microstructures is convex column-shaped, and the cross-section of each light-expanding microstructure is a curved arc segment at the top, and a diagonal straight segment on both sides of the bottom; wherein, Each of the light-expanding microstructures accounts for 13 to 23% of the area of the light-entering surface, the protrusion length of each light-expanding microstructure is between 27 and 33 μm, and the distance between any two adjacent curved segments is between 70 ~76μm, the angle between any two adjacent straight sections between 46~66 degrees; and A plurality of LED light sources are arranged on the light incident surface, and the distance between the LED light sources and the light incident surface is maintained at 0.25~0.45mm, and the distance between any two adjacent LED light sources is between 19.5~19.9mm. As described in Item 6 of the patent application scope, a method for manufacturing a backlight module having both high brightness and high incident angle, wherein the thickness of the light guide plate body is 2.2 mm. As described in item 6 of the patent application scope, a method for manufacturing a backlight module having both high luminosity and high incident light angle, wherein the protruding length of each of the light-expanding microstructures is 30 μm, and any two adjacent ones The distance between equal-curved arc sections is 73 μm, and the angle between any two adjacent straight sections is between 54 and 57 degrees. As described in item 6 of the patent application scope, a method for manufacturing a backlight module having both high brightness and high incident angle, wherein the depth of the light guide groove is 40 μm, and any two adjacent guides The distance between the optical grooves is 300 μm. As described in item 6 of the patent application scope, a method for manufacturing a backlight module having both high brightness and high light incident angle, wherein the distance between the LED light sources and the light incident surface is 0.35mm, any two are adjacent The distance between the LED light sources is 19.7mm.

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