TWI412803B - Light guide stick and back light module using the same - Google Patents

Abstract

A light guide stick and a back light module using the same are provided. The light guide stick includes a body, a light source and a reflector. The body has a plurality of light output structures, an end surface and an outer surface. The light output structures are separately disposed on the outer surface. The light source corresponds to the end surface for providing light emitting into the body. The reflector has a plurality of openings exposing the light output structures, respectively. Therefore, the light provided by the light source is guided out of the body through the reflector and the light output structures.

Description

Light guide bar and backlight module using same

The invention relates to a light guide bar and a backlight module using the same, and particularly relates to a light guide bar for generating a plurality of light sources and a backlight module using the same.

Please refer to FIG. 1 , which shows a schematic diagram of a conventional light guiding rod. The light guide bar 100 includes two light sources 108, a rod body 110, a plurality of diffusion particles 102, and a reflection film 106. The diffusion particles 102 are filled in the rod 110. The reflective film 106 is attached to an outer surface 104 of the rod 110 to reflect the light L contacting the reflective film 106 back into the light guiding rod 100 to avoid loss of the light L. The diffusing particles 102 are used to cause the light L of the light source 108 to be led out of the diffusing particles 102 and then to be led out of the rod 110, and the light to be extracted, that is, the light La, to achieve illumination or specific optical use.

However, the two light sources 108 can only produce one source La, and its use is limited. In addition, since the range of the light exiting region is large (that is, a large area of light is emitted), the overall light output intensity is weak, and thus the directivity of the light exiting light is not good.

The invention relates to a light guiding rod and a backlight module using the same. Since a plurality of light-emitting structures are disposed on the rod of the light guiding rod, a plurality of light sources can be generated by a small number of light sources. Further, since the light-emitting area of the single light source is reduced, the light intensity is increased, and the directivity is thus improved. In this way, specific illumination uses can be achieved.

According to an aspect of the invention, a light guiding rod is proposed. The light guiding rod comprises a rod body, a first light source and a reflecting element. The rod body has a plurality of light emitting structures, a first end surface and an outer surface. The light exiting structures are disposed on the outer surface and are not connected to each other. The first light source is disposed corresponding to the first end surface for emitting a first light into the rod body. The reflective element surrounds the outer surface and has a plurality of light transmissive openings that respectively expose the light exiting structures. Thereby, the first light comes into contact with the reflective element and is reflected back into the rod body, and then the rod is guided through the light-emitting structure.

According to another aspect of the present invention, a backlight module is provided. The backlight module includes a light guide plate and a light guide bar. The light guiding rod is disposed adjacent to the light guide plate. The light guiding rod comprises a rod body, a first light source and a reflecting element. The rod has a plurality of light-emitting structures, a first end surface, and an outer surface. The light-emitting structures are disposed on the outer surfaces of the corresponding incident surfaces and are not connected to each other. The first light source is disposed corresponding to the first end surface for emitting a first light into the rod body. The reflective element surrounds the outer surface and has a plurality of light-transmissive openings, wherein the light-transmissive openings respectively expose the light-emitting structures. Thereby, the first light comes into contact with the reflective element and is reflected back into the rod body, and then passes through the light-emitting structure to lead out the rod body to the light guide plate.

In order to make the above-mentioned contents of the present invention more comprehensible, the preferred embodiments are described below, and the detailed description is as follows:

First embodiment

Please refer to FIG. 2, which is a schematic view of a light guiding rod according to a first embodiment of the present invention. The light guide bar 200 includes a rod 204, a reflective element 206 and a first light source 202. The material of the light guiding rod 200 may be a transparent resin material, such as polycarbonate (PC), polymethyl methacrylate (PMMA) or polyethylene terephthalate (PET). ).

The rod body 204 has two light emitting structures 208 and a first end surface 210. The first light source 202 is disposed corresponding to the first end surface 210. The two light exiting structures 208 are disposed on one of the outer surfaces 214 of the rods 204 and are not connected to each other. Thereby, after the first light L1 is in contact with the reflective element 206 and reflected back into the rod body 204, the light is transmitted to the outside of the rod body 204 through the light-emitting structure 208. The cross-sectional shape of the rod 204 may be a circular shape, a square shape or the like. The cross-sectional shape of the rod 204 of the present embodiment is exemplified by a circular shape.

As shown in Fig. 2, as long as one light source is used, for example, the first light source 202 can generate a plurality of point light sources or line light sources, for example, an effect of generating light Lb emitted from the two light exiting structures 208. Moreover, the light-emitting structure 208 can be disposed at a preset position to achieve the special effect of the light exiting in the preset direction. In this way, the light guiding rod of the embodiment can be applied to the illumination of an art product, and can be directed to the art product in a specific direction, and can further display the characteristics of the art product. Moreover, since the light-emitting structure 208 has a small light-emitting area, the light-emitting intensity is relatively large and concentrated to achieve better directivity.

In addition, the number of light-emitting structures 208 may also be two or more and may be evenly distributed on the outer surface 214 to achieve the effect of light output from the entire periphery. Furthermore, the number of light-emitting structures 208 of the present embodiment is not intended to limit the invention.

As shown in FIG. 2, the reflective element 206 is, for example, a reflective film that surrounds the outer surface 214. The reflective film is disposed on the outer surface 214 in an attached manner. The reflective element 206 has two light transmissive openings 216, and the two light transmissive openings 216 respectively expose the two light exiting structures 208. The reflective element 206 is configured to reflect the first light L1 back into the rod 204 when the first light L1 contacts the reflective element 206. In this way, no light is lost outside the rod 204 to increase the efficiency of the light source. The number of the light-transmissive openings 216 can match the number of the light-emitting structures 208.

In addition, the reflective element 206 can also be a reflective layer (not shown) disposed on the outer surface 214 in a coating manner. Alternatively, please refer to FIG. 3, which is a schematic view of a reflective element according to another embodiment of the present invention. The reflective element can be a reflector 220 that maintains a gap S with the rod 204. In order to achieve the reflection effect, the material of the reflector 220 can be a metal with high reflectivity. Alternatively, a high reflectivity material may be disposed on the inner surface of the reflector 220 to achieve the function of reflecting the first light L1.

Referring to Fig. 4, there is shown a schematic view of the rod and the reflecting member viewed in the direction 4A-4A' in Fig. 2. The cross-sectional profile of the light exiting structure 208 is triangular. However, this is not intended to limit the present invention, and the cross-sectional profile of the light-emitting structure 208 may also be a polygonal portion, an arc, a part of a circle, or a part of an ellipse. Alternatively, the cross-sectional profile of the light exiting structure 208 can also be any combination of a triangle, a polygon, a circle, an arc, and an ellipse. Furthermore, the cross-sectional profile of the light-emitting structure 208 is not limited as long as the light-emitting effect can be achieved. Therefore, the light-emitting structure 208 can also be a rough surface whose profile is irregular. It is within the scope of the invention to have a cross-sectional profile of the light-emitting structure that achieves the light-emitting effect.

In addition, the first light source 202 can also be a light source that emits invisible light, such as an ultraviolet light source. At this time, the rod 204 includes a plurality of fluorescent particles (not shown) distributed in the rod 204. When the ultraviolet light emitted by the ultraviolet light source is irradiated to the fluorescent particles, the fluorescent particles excite the light. Furthermore, the first light source 202 can be a light source that emits visible light or a light source that emits invisible light.

Further, in another embodiment of the light guiding rod, the rod may also include a plurality of diffusing particles. Please refer to FIG. 5, which illustrates a schematic diagram of a rod body further including diffusion particles according to another embodiment of the present invention. The rod 304 of the light guiding rod 300 further includes diffusing particles 302, and the diffusing particles 302 are distributed in the rod 304.

Second embodiment

Please refer to FIG. 6, which is a schematic view of a light guiding rod according to a second embodiment of the present invention. The second embodiment is different from the first embodiment in that the light guide bar 400 of the second embodiment further includes a second light source 402. The rest of the same points are the same reference numerals, and will not be repeated here.

The rod body 204 further has a second end surface 212 corresponding to the first end surface 210. The second light source 402 is disposed corresponding to the second end surface 212 for emitting a second light L2 into the rod body 204. One of the reflective elements 404 of the light guiding rod 400 exposes the second end surface 212 to allow the second light L2 to enter the rod 204. The reflective element 404 can be a reflective film disposed on the outer surface 214 of the rod 204 in an attached manner.

The light guide bar 400 of the present embodiment uses two light sources such that the light Lc emitted by the light exiting structure 208 is more intense.

Third embodiment

Please refer to FIG. 7 , which is a schematic diagram of a backlight module according to a third embodiment of the present invention. The third embodiment is different from the second embodiment in that the third embodiment applies the light guide bar of the present invention to a backlight module 500.

The backlight module 500 includes a light guide plate 502 and a light guide bar 504 disposed adjacent to the light guide plate 502. The light guide bar 504 includes a rod 506 and a reflective element 508. The rod 506 has three light exiting structures 510 and one of the first end faces 512 and a second end face 514. The first light source 202 corresponds to the first end surface 512 , and the second light source 402 is disposed corresponding to the second end surface 514 . The light guide plate 502 has an incident surface 520, and the light exiting structures 510 are disposed on the outer surface 516 of the corresponding incident surface 520 and are not connected to each other. The first light L1 and the second light L2 are in contact with the reflective element 508 and then reflected back into the rod body 506, and then the light output structure 510 is used to lead the rod body 506 to the light guide plate 502.

The reflective element 508, for example, a reflective film, surrounds the outer surface 516 and exposes the first end surface 512 and the second end surface 514. The reflective film is disposed on the outer surface 516 in an attached manner. Reflective element 508 has three light transmissive openings 518. The number of the light-transmissive openings 518 can match the number of the light-emitting structures 510, and the three light-transmissive openings 518 respectively expose the three light-emitting structures 510. The reflective element 508 is configured to reflect the first light L1 and the second light L2 back into the rod 506 when the first light L1 and the second light L2 contact the reflective element 508. In this way, no light is lost outside the rod 506 to increase the efficiency of the light source.

In this embodiment, only two light sources, namely the first light source 202 and the second light source 402, are required to generate two or more point light sources or line light sources to illuminate the light guide plate 502, for example, to generate three rays of light to guide the light guide plate 502. .

Although the light source of the present embodiment is exemplified by two, that is, the first light source 202 and the second light source 402, in other embodiments, the light guide bar 504 of the backlight module 500 may only have the first light source 202 and One of the second light sources 402. In this way, the effect of generating a plurality of point light sources or line light sources can also be achieved.

The light-emitting structure 510 of the light guide bar 504 of the present embodiment is exemplified by three. However, in other embodiments, the light-emitting structure 510 of the light guide bar 504 may be three or more, and the number thereof is not affected. The limitations of this embodiment.

The light guide bar and the applied backlight module disclosed in the above embodiments of the present invention have a plurality of advantages, and only some of the advantages described below are as follows:

(1) The light-emitting structure is separately disposed on the rod so that a plurality of point light sources or line light sources can be produced by a small number of light sources.

(2). Since the area of the light outgoing structure becomes smaller, the light intensity is relatively stronger, and the directivity is thus better.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100, 200, 300, 400, 504. . . Light guide

102, 302. . . Diffused particle

104. . . The outer surface

106. . . Reflective film

108. . . light source

202. . . First light source

204, 304, 506. . . Rod

206, 404, 508. . . Reflective element

208, 510. . . Light structure

210, 512. . . First end face

212, 514. . . Second end face

214, 516. . . The outer surface

216, 518. . . Light transmission opening

220. . . Reflector

302. . . Diffused particle

402. . . Second light source

500. . . Backlight module

502. . . Light guide

520. . . Incident surface

L, La, Lb, Lc, Le. . . Light

L1. . . First light

L2. . . Second light

S. . . gap

Figure 1 is a schematic view of a conventional light guide bar.

2 is a schematic view of a light guiding rod according to a first embodiment of the present invention.

FIG. 3 is a schematic view showing a reflective element according to another embodiment of the present invention.

Fig. 4 is a view showing the rod body and the reflecting member viewed in the direction 4A-4A' in Fig. 2.

FIG. 5 is a schematic view showing a rod body further including diffusion particles according to another embodiment of the present invention.

Figure 6 is a schematic view of a light guiding rod according to a second embodiment of the present invention.

FIG. 7 is a schematic diagram of a backlight module according to a third embodiment of the present invention.

200. . . Light guide

202. . . First light source

204. . . Rod

206. . . Reflective element

208. . . Light structure

210. . . First end face

214. . . The outer surface

216. . . Light transmission opening

L1. . . First light

Lb. . . Light

Claims (22)

A light guiding rod comprising: a rod body having a plurality of light emitting structures, a first end surface and an outer surface, wherein the light emitting structures are disposed on the outer surface and are not connected to each other; a light source corresponding to the first end surface for emitting a first light into the rod body; and a reflective element surrounding the outer surface and having a plurality of light transmissive openings, wherein the light transmissive openings are respectively The light-emitting structures are exposed; thereby, the first light is contacted with the reflective element and reflected back into the rod body, and then the rod body is derived by contacting the light-emitting structures. The light guide bar according to claim 1, wherein a cross-sectional profile of each of the light-emitting structures is a triangle, a polygon, an arc, a part of a circle or a part of an ellipse. The light guide bar of claim 1, wherein the rod body further comprises a plurality of diffusion particles distributed in the rod body. The light guide bar of claim 1, wherein the rod body further comprises a plurality of fluorescent particles distributed in the rod body. The light guide bar of claim 4, wherein the first light source is an ultraviolet light source that emits ultraviolet light. The light guide bar according to claim 1, wherein the material of the rod body is a transparent resin material. The light guide bar according to claim 6, wherein the material of the rod is polycarbonate (PC), polymethyl methacrylate (PMMA) or polyethylene terephthalate. Polyester (polyetbylene terephthalate, PET). The light guide bar of claim 1, further comprising a second light source, and the rod body further includes a second end surface corresponding to the first end surface, wherein the second light source corresponds to the second end surface Settings. The light guide bar of claim 1, wherein the reflective element is a reflective film attached to the outer surface. The light guide bar of claim 1, wherein the reflective element is a reflective layer coated on the outer surface. The light guide bar of claim 1, wherein the reflective element is a reflector that maintains a gap with the rod. A backlight module includes: a light guide plate including an incident surface; and a light guide bar disposed adjacent to the light guide plate, and comprising: a rod body having a plurality of light emitting structures, a first end surface, and an outer surface The light emitting structures are disposed on the outer surface corresponding to the incident surface and are not connected to each other; a first light source is disposed corresponding to the first end surface for emitting a first light into the And a reflective member surrounding the outer surface and having a plurality of light-transmissive openings, wherein the light-transmissive openings respectively expose the light-emitting structures; thereby, the first light is contacted to the reflective element and reflected back After the rod body is exposed, the rod body is led to the light guide plate by contacting the light-emitting structures. The backlight module of claim 12, wherein a cross-sectional profile of each of the light-emitting structures is a triangle, a polygon, an arc, a part of a circle or a part of an ellipse. The backlight module of claim 12, wherein the rod body further comprises a plurality of diffusion particles distributed in the rod body. The backlight module of claim 12, wherein the rod body further comprises a plurality of fluorescent particles distributed in the rod body. The backlight module of claim 15, wherein the first light source is an ultraviolet light source that emits ultraviolet light. The backlight module of claim 12, wherein the material of the rod is a transparent resin material. The backlight module of claim 17, wherein the material of the rod is polycarbonate, polymethyl methacrylate or polyethylene terephthalate. The backlight module of claim 12, further comprising a second light source, and the rod body further includes a second end surface corresponding to the first end surface, wherein the second light source corresponds to the second end surface Settings. The backlight module of claim 12, wherein the reflective element is a reflective film attached to the rod. The backlight module of claim 12, wherein the reflective element is a reflective layer coated on the rod. The backlight module of claim 12, wherein the reflective element is a reflector that maintains a gap with the rod.