TWI472816B - Light guide plate - Google Patents

Description

Light guide

The invention relates to a light guide plate, in particular to a light guide plate used for a direct type light source module.

The backlight module of the conventional liquid crystal display is disposed on the back of the liquid crystal panel to provide a display light source required for the liquid crystal panel. The backlight module can be divided into "side-light" and "straight-down" designs according to the position of the light source. The backlight module of the "straight down" design gradually uses a plurality of light-emitting diodes as a light source to replace the traditional white heat lamp. Or fluorescent tube. When the light-emitting diode is used as a light source, a light-expanding distance is usually reserved and disposed under the liquid crystal panel to provide a uniform light source of the liquid crystal panel. Therefore, the "direct-down" design of the backlight module will be very thick. The structure of the "side-light" backlight module is lighter from the side, so it will be thinner; however, the number of LEDs to be used is at least 2.5 times that of the "direct-type" backlight module of the same size.

Therefore, if the light-emitting diode can be directly attached to the back surface of the light guide plate, the advantages of both of them can be combined. However, in practice, when directly bonding, the intensity of the light is strongest in the direction of the positive viewing angle (that is, the normal direction of the light emitting surface of the light emitting diode), so the light emitting diode must be illuminated by the light guiding structure on the light guiding plate. The light in the direction of the positive viewing angle is reflected toward the side, but the light-expanding ability of the light-expanding structure has its limit. Therefore, in the orthographic projection area where the light-emitting diode directly fits the position of the light-guiding plate, a bright block is still formed, resulting in a surface. The surface of the light source is uneven in brightness.

In view of this, how to develop a backlight module and improve the above-mentioned lack of inconvenience and inconvenience is an important issue that the relevant industry is currently unable to delay.

In view of the prior art, an object of the present invention is to solve the problem that a direct-lit light source module generates a bright block having a brightness higher than an average value at a position corresponding to a light-emitting element.

An embodiment of the invention provides a light guide plate, which cooperates with a light-emitting element to form a light source module, and the light-emitting element has a light-emitting surface. The light guide plate and the plurality of point light sources cooperate to form a direct-type backlight module; the plurality of point light sources directly fit on the light-incident surface of the back surface of the light guide plate, so that the light-emitting surface on the front surface of the light guide plate forms an original bright block. The light guide plate includes a plurality of first light-take structures and a plurality of second light-take structures, wherein the plurality of first light-take structures are designed to correspond to the original bright blocks, and overlap with the plurality of point light sources in the orthogonal projection direction. . The plurality of second light-harvesting structures are disposed around any of the first light-harvesting structures to share the light of the original bright blocks to form an additional post-lighting block. The first light-taking structure and the second light-harvesting structure are both formed by a plurality of grooves arranged in a radial shape. The beneficial effect is that the rear bright blocks share the light of the original bright block, and the human visual perception is considered to be The light-emitting surface on the front side of the light board is a surface light source that is uniform and has no bright and bright blocks.

In other embodiments, the trench may be a V-shaped trench or a U-shaped trench; that is, the trench has a V-shaped or U-shaped cross section. Of course, the section of the trench can also be other symmetrical geometry.

On the other hand, the grooves of the first light-take structure and the second light-take structure may be designed on the light-emitting surface of the front surface of the light guide plate, or may be designed on the light-incident surface of the back surface of the light guide plate, or One design is on the front side of the light guide and the other is on the back of the light guide. From a technical point of view, in addition to the plurality of first light-taking structures and second light-harvesting structures composed of grooves, the light-guide plate can be designed with other optical microstructure patterns that help to emit light. In order to facilitate processing, to avoid the existence of grooves and optical microstructure patterns, and to interfere with each other in design freedom, the grooves and optical microstructure patterns are usually designed on the front and back sides of the light guide plate, respectively. In other words, if the first light extraction structure and the second light extraction structure are on the front side of the light guide plate, the optical microstructure pattern is on the back side of the light guide plate; and vice versa.

In addition, in other embodiments, any one of the plurality of first light-harvesting structures is a m-shaped structure composed of eight grooves arranged in a radial shape, and each of the grooves is directed to one of the second light-taketing structures. . Of course, other radial first light-taking structures are also feasible, and do not necessarily have to be a m-shaped structure. As long as the second light-receiving structure can be matched, the original bright blocks and the rear-made bright blocks can be evenly distributed on the light guide plate. . Further, any of the foregoing grooves may also be branched in a Y-shape to connect the two sub-grooves; in other words, the grooves may also be branched like a dendritic shape. In actual design, a branch groove may be considered. The groove depth is less than the groove depth of the branch.

Thereby, the light guide plate is disposed on the light-emitting surface and corresponding to the light-collecting structure arranged around the light-emitting element, so that the rear bright block can share the light of the original bright block, and in the human visual sense, the light guide plate front is considered The illuminating surface is a surface light source that is uniform and has no bright and bright blocks. Therefore, the present invention can effectively eliminate the problem that the light source module produces a distinct bright block at the arrangement of the corresponding light-emitting elements, thereby providing a planar light source having uniform light intensity.

1, 1a, 1b‧‧‧ light guide

10‧‧‧Into the glossy surface

12‧‧‧Glossy

14‧‧‧First light extraction structure

16‧‧‧Second light extraction structure

18, 18a‧‧‧ trench

19‧‧‧Optical microstructures

2‧‧‧ point light source

20‧‧‧ point light source

3‧‧‧Direct type backlight module

The first figure is an exploded view of a light guide plate and its peripheral structure according to an embodiment of the present invention.

The second figure is a plan view of a light guide plate according to another embodiment of the present invention.

The third figure is a partial enlarged view of the light guide plate shown in the second figure.

Fig. 4 is a cross-sectional view showing a light guide plate and a peripheral structure thereof according to still another embodiment of the present invention.

Fig. 5 is a cross-sectional view showing a light guide plate and a peripheral structure thereof according to still another embodiment of the present invention.

The above and other objects, features, and advantages of the present invention will be better understood from the following description of the preferred embodiments.

Referring to the first figure, an exploded view of a light guide plate and its peripheral structure according to an embodiment of the present invention. The light guide plate 1 and the plurality of point light sources 2 cooperate to form a direct-type backlight module 3, which can be realized, for example, by a light-emitting diode.

The light guide plate 1 includes a light incident surface 10 and a light exit surface 12 with respect to the light incident surface 10; in the present embodiment, the light incident surface 10 is the back surface of the light guide plate 1, and the light exit surface 12 is the front surface of the light guide plate 1. The light guide plate 1 is generally a rectangular structure having a uniform thickness and a light transmissive property obtained by using polymethylmethacrylate (PMMA) or polystyrene (PS), but the material of the light guide plate 1 is not It is excluded to use other resin materials having light transmissive properties, such as acrylic resin (Acrylic Resin), cycloolefin polymer (COC), polycarbonate (PC) or silicone (Silicone).

The plurality of point light sources 2 are directly attached to the light incident surface 10 of the light guide plate 1, and the original light block is formed on the light exit surface 12 on the front surface of the light guide plate 1. A plurality of point light sources 2 are arranged on a circuit board 20 and electrically connected to the circuit board 20, and the plurality of point light sources 2 are captured by the circuit board 20. The power required to light up.

The light guide plate 1 includes a plurality of first light extraction structures 14 and a plurality of second light extraction structures 16, as shown in the second figure. The plurality of first light-take structures 14 are designed to correspond to the original bright blocks, and overlap the positions of the plurality of point light sources 2 in the forward projection direction, as shown in the first figure. The plurality of second light-harvesting structures 16 are disposed around any of the first light-harvesting structures 14 to share the light of the original bright blocks to form an additional post-lighting block. The rear bright block is used to share the light of the original bright block. Therefore, in the human visual perception, the light-emitting surface 12 on the front side of the light guide plate 1 is considered to be a surface light source having no uniform bright blocks.

The first light-take structure 14 and the second light-take structure 16 can be simultaneously disposed on the light-emitting surface 12 of the front surface of the light guide plate 1. Of course, the first light-take structure 14 and the second light-take structure 16 can also be disposed on the back surface of the light guide plate 1 at the same time. The light incident surface 10 or one of the first light extraction structure 14 and the second light extraction structure 16 is disposed on the light emitting surface 12 on the front surface of the light guide plate 1 , and the light incident surface 10 on the back surface of the light guide plate 1 .

The first light take-up structure 14 and the second light-take structure 16 are both formed by a plurality of grooves 18 arranged in a radial shape, as shown in the third figure. The groove 18 may be a V-shaped groove or a U-shaped groove, that is, the groove 18 has a V-shaped or U-shaped cross section; of course, the groove 18 may have other symmetry sections. Geometric shape. In this embodiment, any one of the plurality of first light-take structures 14 is a m-shaped structure composed of eight grooves 18 arranged in a radial shape, and each of the grooves 18 points to one of the second light-receiving Structure 16, as shown in the second figure. In actual implementation, the first light-harvesting structure 14 may also be other radial structures. As long as the second light-harvesting structure 16 can be matched, the original bright block and the rear-made bright block can be evenly distributed on the light guide plate 1.

In summary, the light guide plate 1 of the present invention utilizes the direction in which the point light source 2 is projected. The first light-harvesting structure 14 and the second light-harvesting structure 16 disposed around the first light-harvesting structure 14 share the light of the original bright spot to form an additional post-production bright spot, so that the human light perception is considered to be the front side of the light guide plate 1 The light-emitting surface 12 is a surface light source that is uniform and has no bright and bright blocks.

4 is a cross-sectional view of a light guide plate and its peripheral structure according to still another embodiment of the present invention. The light guide plate 1a shown in the fourth figure is similar to the light guide plate 1 of the first embodiment, and the same elements are denoted by the same reference numerals. It is to be noted that the difference between the two is that the groove 18a of the light guide plate 1a shown in the fourth figure is in a Y-shaped branch.

The groove 18a has a tip such that the curvature distribution of the groove 18a is discontinuous. In actual implementation, the groove 18a may also connect two sub-grooves, so that the groove 18a is branched in a continuous manner, and in actual design, the groove depth of the branch can be made smaller than the groove depth of the branch. . The function and related description of each element of the light guide plate 1a are substantially the same as those of the light guide plate 1 of the first embodiment, and will not be described herein. The light guide plate 1a can at least achieve the same function as the light guide plate 1.

5 is a cross-sectional view showing a light guide plate and a peripheral structure thereof according to still another embodiment of the present invention. The light guide plate 1b shown in the fifth embodiment is similar to the light guide plate 1 of the first embodiment, and the same elements are denoted by the same reference numerals. It is to be noted that the difference between the two is that the front surface of the light guide plate 1b shown in the fifth figure is designed with an optical microstructure pattern 19 which helps to emit light.

The optical microstructure pattern 19 is designed to homogenize the uniformity of light emitted by the light exit surface 12 of the front surface of the light guide plate 1b. In order to improve the convenience of processing the light guide plate 1b, and to avoid the interference of the design of the groove 18 and the optical microstructure pattern 19, the groove 18 and the optical microstructure pattern 19 are respectively designed on the front surface of the light guide plate 1b. versus back. In this embodiment, the groove 18 is a light-emitting surface 12 designed on the front surface of the light guide plate 1b, and the groove 18 of the first light-take structure 14 and the second light-take structure 16 is a light-incident surface 10 designed on the back surface of the light guide plate 1b. Of course, in the actual implementation, the groove 18 may also be the light incident surface 10 designed on the back surface of the light guide plate 1b. The first light extraction structure 14 and the second light extraction structure 16 are the light exit surface 12 designed on the front surface of the light guide plate 1b. .

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

1‧‧‧Light guide plate

10‧‧‧Into the glossy surface

12‧‧‧Glossy

14‧‧‧First light extraction structure

2‧‧‧ point light source

20‧‧‧ point light source

3‧‧‧Direct type backlight module

Claims (5)

A light guide plate is combined with a plurality of point light sources to form a direct-type backlight module. The point light sources are directly attached to a light incident surface on the back surface of the light guide plate, so that a light-emitting surface on the front surface of the light guide plate forms an original bright block. The light guide plate includes: a plurality of first light-take structures, wherein the first light-take structure is designed to correspond to a position of the original bright block, and coincides with the position of the point light sources in a right projection direction, and the like The first light extraction structure is formed by a plurality of grooves arranged in a radial shape; and the plurality of second light extraction structures are disposed around any of the first light extraction structures, and the second light extraction structures are also a plurality of grooves arranged in a radial arrangement for sharing the light of the original bright block to form an additional post-production bright block; wherein any of the first light-receiving structures is arranged by eight grooves arranged in a radial shape The m-shaped structure is formed, and each groove is directed to one of the second light-take structures, and any of the grooves is branched in a Y-shape to connect the two sub-grooves. The light guide plate of claim 1, wherein the first light extraction structure is the light exit surface disposed on the front surface of the light guide plate. The light guide plate of claim 1, wherein the second light extraction structure is the light exit surface disposed on the front surface of the light guide plate. The light guide plate of claim 1, wherein the first light extraction structure is the light incident surface disposed on the back surface of the light guide plate. The light guide plate of claim 1, wherein the second light extraction structure is the light incident surface disposed on the back surface of the light guide plate.