TWI424207B - Light guide plate - Google Patents

Description

Light guide

The present invention relates to a light guide plate, and more particularly to a light guide plate for producing a surface light source.

Light Emitting Diode (LED), or High Light Emitting Diode (HLED) has long life, small size, low current, and no pollution. Therefore, it is in the LED industry. When optimistic, the use of LED as a light source has gradually replaced the traditional cold cathode lamp.

Referring to FIG. 1 , a backlight module 1 of a general liquid crystal display is used as an example, and mainly includes a light guide plate 11 and a plurality of light emitting diodes 12 disposed on one side of the light guide plate 11 . When the light-emitting diodes 12 are incident on the light guide plate 11, the light guide plate 11 converts the line light source into a surface light source.

However, since the light-emitting areas of the light-emitting diodes 12 are small and approach the point light source, the luminous flux thereof gradually decreases as the distance into the light guide plate 11 increases, and thus, close to the light-emitting diodes 12 The portion will be the brightest, and the portion away from the light-emitting diodes 12 will be darker. Although the dots or ribs on the light guide plate 11 can cause light refraction in the traveling light, and enhance the far-reaching portion. Brightness, however, for the portion adjacent to the light-emitting diode 12, local bright spots or bright lines are still generated because the brightness is significantly brighter, and this problem will be due to the light guide plate 11 The area (or side length) is increased, or the number of uses is lowered by using the high-power light-emitting diode 12, resulting in an increase in the pitch of the adjacent light-emitting diodes 12, which exacerbates the situation of bright spots or bright lines. As shown in Annexes 1 and 2, after simulation calculations, it is found that the brightness of a general bright line or a bright spot can be up to three times the average luminance, in other words, the uniformity is only about 30%.

In order to improve the influence of the hot spots or bright lines, a border (not shown) is generally covered on the side of the light guide plate 11 to block the hot spots, but the border The arrangement not only reduces the light-emitting area of the light guide plate 11, but also reduces the utilization rate of the light source, which is quite inconsistent with economic benefits.

Accordingly, it is an object of the present invention to provide a light guide plate which can effectively improve uniformity and amplify an illumination area.

Therefore, the light guide plate of the present invention comprises a body, a plurality of grooves, a plurality of first microstructure groups, and a plurality of second microstructure groups. The body has a light exiting surface formed on a surface, and a light incident surface formed on a side surface facing the light emitting diodes. The grooves are formed in the body, and an optical path is defined adjacent to the light incident surface and the light incident surface. The first microstructure groups are disposed on the light incident surface and are respectively opposite to the light emitting diodes for expanding an incident angle of incident light to cause incident light to enter the light entrance channel. The second microstructure groups are disposed in the grooves for destroying the total reflection path of the incident light in the light entrance channel, and guiding the incident light toward the body.

The effect of the invention is that the first microstructure group disperses the incident light, and the arrangement of the grooves is used to evenly distribute the light, thereby successfully overcoming the direct brightness unevenness and the traditional hot spots. The light guide plate produces a uniform surface light source, which in turn can amplify the illumination area.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Referring to Figures 2 and 3, a preferred embodiment of the light guide plate of the present invention uses the light-emitting diode 2 as a light source. The light guide plate comprises a body 3, a plurality of grooves 4, a plurality of first microstructure groups 5, and a second number of microstructure groups 6 (Fig. 6).

Referring to FIG. 2, FIG. 3, and FIG. 4, the body 3 has a light-emitting surface 31 formed on a surface, a light-receiving surface 32 formed on the other surface and opposite to the light-emitting surface 31, formed on one side and facing A light incident surface 33 of the light-emitting diodes 2 and a plurality of microstructures 34 formed on the light-receiving surface 32.

The groove 4 is formed in the body 3, and defines a light entrance channel 30 adjacent to the light incident surface 33 and the light entrance surface 33, and has a slot adjacent to the light entrance channel 30 and facing the body 3. Wall 41.

The first microstructure groups 5 are disposed on the light incident surface 33 and are respectively opposed to the light emitting diodes 2 and have a plurality of micro structures 51 that are V-shaped and face the light emitting diodes 2 . The microstructures 51 are respectively formed with a main structure region 51a arranged in the middle portion and facing the light-emitting diode 2, and two sub-structure regions 51b arranged on both sides of the main structure region 51a. The microstructure 51 in the main structure region 51a has an angle θ ₁ of 90° to 140°, and is 120° in the preferred embodiment. The microstructures 51 in the substructure regions 51b have an angle θ ₂ bound to 10° to 160°.

Referring to Figures 3, 5, and 6, the second microstructure groups 6 are disposed in the groove walls 41 of the grooves 4, respectively, and have a plurality of microstructures 61, respectively. The microstructures 61 are respectively formed in a dense arrangement with a high-density region 61a located in the middle of the trench wall 41, and are formed in an evacuated arrangement on both sides of the high-density region 61a and adjacent to the light-emitting diode 2 The second low density zone 61b. The microstructures 61 can be a combination of protrusions, recesses, and the like, and the shapes can be V-shaped, ladder-shaped, semi-circular, dot, and a combination thereof.

Referring to FIG. 3, FIG. 4, and FIG. 5 and FIG. 6, when the light-emitting diodes 2 emit light toward the light-incident surface 33, part of the incident light acting on the first microstructure groups 5 will be directed toward The two sides of the light-emitting diode 2 are diverged, and due to the special angle design of the main structure region 51a and the sub-structure region 51b, the incident light of the front side and the front side of the light-emitting diode 2 can be expanded to the two sides. And entering the light entrance channel 30, thereby not only reducing the luminous flux density directly in front of the light emitting diodes 2, but also guiding the light emitting diodes 2, that is, each of the light emitting diodes 2 Luminous flux on both sides.

At this time, the incident light entering the light entrance channel 30 travels in the light entrance channel 30 according to the total reflection phenomenon, and the microstructures 61 change the traveling path of the light, thereby destroying the original total reflection path and making the incident Light passes through the grooves 4 and diverge toward the body 2. It is worth mentioning that, since the left and right sides of the optical channel 30 are light-in areas, the microstructures 61 can be arranged in an evacuation manner to form a low-density region 61b, and then form a high height as the light-in distance increases. The density region 61a causes the light rays scattered by the entire light channel 30 to be uniform, thereby enhancing the brightness between the adjacent light-emitting diodes 2, so that the light-emitting diodes 2 are directly in front and on both sides. The smooth surface 33 has a luminance that tends to be uniform.

Finally, the incident light entering the body 3 also travels on the body 3 according to the total reflection phenomenon, and the microstructures 34 change the traveling path of the light to destroy the original total reflection path, so that the incident light faces the light-emitting surface 31. Divergence, forming a surface light source.

Referring to Appendix 3, it can be clearly seen from the illuminance diagram and the lateral illuminance section diagram that the general light guide plate will produce bright spots at the entrance light, and the uniformity is only about 16%. When the aforementioned light guide plate is added to the first microstructure group After 5, the situation of the bright spot has been improved, and the uniformity can reach 47%. If the second microstructure group 6 and the grooves 4 are added, the luminous effect can be more ideal, and the uniformity can be as high as 62%. Compared with the prior art, the brightness uniformity is about 16%~47%, which is obviously increased by more than 15%. Not only can the bright spot condition be greatly improved, but also the available area of the light guide plate can be increased.

It is worth mentioning that, because the bright spot of the light guide plate 2 has been greatly improved, the brightness uniformity can be effectively improved, and the invention can be applied to the lighting fixture, and the glare can be successfully achieved, and the comfort of direct vision brightness can be improved. aims.

According to the above description, the light guide plate of the present invention has the following advantages and effects:

1. The present invention is to expand the incident angle of the incident light by the first microstructure group 5, and to match the grooves 4 and the second microstructure group 6 to uniformly distribute the light, which can not only make the light, The dark difference is minimized, effectively reducing the bright spot or bright line, and the overall visual effect of homogenization in terms of brightness.

2. According to the foregoing, the present invention can successfully overcome the phenomenon of direct brightness unevenness and traditional hot spots, so that the whole light guide plate 2 can produce a relatively uniform surface light source, and can reduce the coverage or shielding area, thereby expanding Increasing the available area makes the invention more industrially usable.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

2‧‧‧Lighting diode

3‧‧‧ Ontology

30‧‧‧Into the light channel

31‧‧‧Glossy

32‧‧‧Fracture surface

33‧‧‧Into the glossy surface

34‧‧‧Microstructure

4‧‧‧ Groove

41‧‧‧ slot wall

5‧‧‧First microstructure group

51‧‧‧Microstructure

51a‧‧‧Main Structure Area

51b‧‧‧Substructure area

6‧‧‧Second microstructure group

61‧‧‧Microstructure

61a‧‧‧High-density area

61b‧‧‧Low-density area

Figure 1 is a top view showing a general lighting module;

Figure 2 is a top plan view showing a preferred embodiment of a light guide plate of the present invention;

Figure 3 is a front elevational view of the preferred embodiment;

4 is a schematic layout view of a first microstructure group in the preferred embodiment;

Figure 5 is a schematic view showing a layout of a second microstructure group in the preferred embodiment; and

Figure 6 is a partial enlarged view of the preferred embodiment guiding incident light.

Annex 1: Illumination diagram of general lighting module;

Annex 2: The transverse illumination line drawing of Annex 1 above; and

Attachment 3: a general light guide plate and a light guide plate are added to the first microstructure group, and the light guide plate is added to the first microstructure group, the second microstructure group and the groove, and the illuminance map and the lateral illumination line diagram.

2. . . Light-emitting diode

3. . . Ontology

30. . . Optical channel

31. . . Glossy surface

33. . . Glossy surface

4. . . Groove

41. . . Slot wall

5. . . First microstructure group

Claims (7)

A light guide plate is a light-emitting diode as a light source, the light guide plate comprises: a body having a light-incident surface formed on one side facing the light-emitting diodes; and a plurality of grooves formed in the body And an optical channel is defined adjacent to the light incident surface and the light incident surface, and has a groove wall adjacent to the light incident channel and facing the body; and the first microstructure group is disposed on the light incident surface And respectively for opposing the light-emitting diodes, for expanding the incident angle of the incident light, causing the incident light to enter the light-incident channel; and the second microstructure group, the groove walls disposed in the grooves, for The total reflection path of the incident light in the light entrance channel is broken, and the incident light is guided toward the body. The light guide plate of claim 1, wherein the first microstructure groups each have a V-shape and a number of microstructures facing the light-emitting diodes. According to the light guide plate of claim 2, wherein the first microstructure groups are respectively formed with a main structure region arranged in the middle portion and facing the light emitting diode, and arranged in the main structure region The two sub-structure regions on the side, the microstructure angle of the main structure region is between 90° and 140°. The light guide plate according to Item 3 of the patent application scope, wherein the microstructure angles in the sub-structure regions are between 10° and 160°. According to the light guide plate of claim 1, wherein the first The microstructure of the two microstructure groups can be a convex portion, a concave portion, or a combination thereof. The light guide plate according to claim 5, wherein the microstructure of the second microstructure group may be a V shape, a ladder shape, a semicircle shape, a mesh point or a combination thereof. The light guide plate of claim 1, wherein the second microstructure groups each have a micro-structure, and the microstructures are respectively formed in a dense arrangement with a high-density region located in the middle of the groove wall. And forming, in an evacuated arrangement, two low-density regions located on two sides of the high-density region and adjacent to the light-emitting diode.