WO2012114553A1

WO2012114553A1 - Light guiding member and light emitting device provided with same

Info

Publication number: WO2012114553A1
Application number: PCT/JP2011/066450
Authority: WO
Inventors: 小泉　秀樹; 田中　敏裕
Original assignee: パナソニック株式会社
Priority date: 2011-02-21
Filing date: 2011-07-20
Publication date: 2012-08-30
Also published as: JP2012174445A

Abstract

A light guiding member (10) guides light incident through entry surfaces (11, 11) which are on both ends thereof and are disposed between light sources (2, 2), which are disposed so as to face each other and outputs light from an exit surface (12) provided so as to intersect the entry surfaces. On a reflecting surface (13) provided on the side opposite to the exit surface so as to intersect the entry surfaces are provided a large number of reflecting recessed grooves (14) having a prism shape and oriented in a direction orthogonal to the direction the light sources face. Spaces are opened therebetween along this facing direction, and a substantially symmetrical shape is formed sandwiching the substantial center (3) thereof in that facing direction.

Description

Light guide member and light emitting device including the same

The present invention is disposed between opposed light sources, guides light incident from incident surfaces on both end faces, and emits light from an exit surface provided to intersect the incident surface, and The present invention relates to a light emitting device including the same.

Conventionally, there has been known a light guide member that is disposed between opposed light sources and that guides light incident from incident surfaces on both end faces and emits light from an exit surface provided to intersect the incident surface. It has been.

For example, Patent Document 1 below discloses a rod-shaped light guide that emits light from a light emitting unit disposed at each of both ends in the longitudinal direction from the upper surface of one side surface in the longitudinal direction. A scattering dot pattern for irregularly reflecting light introduced into the rod-shaped light guide is formed on the bottom surface of the top surface of the rod-shaped light guide opposite to the exit surface.

Japanese Patent Laid-Open No. 2005-198106

However, the rod-shaped light guide having the scattering dot pattern as described above has a problem that light is irregularly reflected and it is relatively difficult to improve the directivity of the reflected light. In addition, since such a scattered dot pattern generally needs to be formed by printing a white paint or the like, there is a problem that the manufacturing process becomes complicated.

The present invention has been made in view of the above circumstances, and provides a light guide member capable of improving the directivity of light emitted from the emission surface while having a simple structure, and a light emitting device including the same. It is an object.

In order to achieve the above object, a light guide member according to the present invention is disposed between opposed light sources, guides light incident from incident surfaces on both end surfaces, and intersects the incident surface. A light guide member that emits from the exit surface provided in the above manner, along a direction orthogonal to the facing direction of the light source, on a reflective surface provided on the opposite side of the exit surface so as to intersect the entrance surface A large number of prismatic reflective grooves are provided along the opposing direction and symmetrically with respect to the center in the opposing direction.

In the present invention, the reflection concave groove of the reflection surface may be configured to reflect the light from the incident surface toward the emission surface so as not to diffuse along the facing direction.

Further, in the present invention, the reflection concave groove of the reflection surface may be configured to reflect light from the incident surface in a direction in which the light is diffused obliquely along the facing direction.

In order to achieve the above object, a light-emitting device according to the present invention includes the light guide member according to the present invention and a light source disposed opposite to both end faces of the light guide member. To do.

It is preferable that the reflective ditch has a length direction. The length direction of the reflective ditch is defined as a direction orthogonal to the facing direction of the light source. The reflective ditch has a cross section along a direction orthogonal to the length direction. The cross section of the reflective ditch is formed in a V shape.

The cross section of the reflective ditch has a triangular shape, and the reflective ditch is preferably formed in a V shape.

The light guide member according to the present invention and the light emitting device including the light guide member are configured as described above.
Although the structure is simple, the directivity of light emitted from the emission surface can be improved.

(A), (b) shows typically an example of the light-emitting device provided with the light guide member based on one Embodiment of this invention, (a) is a schematic plan view, (b) is schematic. It is a front view. (A), (b) shows typically an example of the light-emitting device provided with the light guide member which concerns on other embodiment of this invention, (a) is a schematic plan view, (b), It is a schematic front view.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a conceptual explanatory diagram for explaining an example of a light guide member according to the first embodiment and a light emitting device including the light guide member.

As shown in FIG. 1, the light emitting device 1 according to the present embodiment includes a light guide member 10 and an LED (light emitting diode) as a light source disposed opposite to both end faces 11 of the light guide member 10. The

light source units

2 and 2 are provided. Although not shown, the light emitting device 1 is provided with a casing for housing the light guide member 10 and the

light source units

2 and 2, a translucent cover member, and the like.

The

light source units

2 and 2 include a substrate on which electronic components such as LEDs and connectors as light emitting elements serving as a light source are mounted, a substrate case that accommodates the substrate, and the like. The LED may be of a shell type in which a light emitting element (LED element) is sealed with a resin or the like, or may have a chip shape, or a surface mount type. Good. Moreover, it is not restricted to what provided single LED, It is good also as an aspect which arranges several LED in parallel or arranges LED which radiate | emits several different color light in parallel.

In the present embodiment, the light guide member 10 has a long, substantially rectangular column shape, and both end surfaces in the longitudinal direction are

incident surfaces

11, 11, and the

light source units

2, 2 are respectively provided on the

incident surfaces

11, 11. Provided. In other words, in the present embodiment, the light guide member 10 has an elongated shape along the facing direction of the

light source units

2 and 2.

Note that the facing direction is defined as a direction in which a plurality of light sources are facing each other.

The light guide member 10 is integrally formed from a light-transmitting or transparent resin material such as acrylic resin or polycarbonate resin, or a material having a high refractive index such as transparent glass.

Further, an exit surface 12 is provided so as to intersect the

entrance surfaces

11, 11, and a reflection surface 13 is provided on the opposite side of the exit surface 12 so as to intersect the

entrance surfaces

11, 11. That is, the emission surface 12 and the reflection surface 13 are provided so as to be substantially parallel. The

remaining side surfaces

15 and 15 provided so as to intersect the incident surface 11 are also reflecting surfaces that reflect the light to be guided.

That is, the light guide member 10 guides the light emitted from the

light source units

2 and 2 and incident from the

incident surfaces

11 and 11 by the reflecting

surfaces

13, 15 and 15 along the longitudinal direction. It is a so-called edge light structure that emits from the exit surface 12 while shining.

Also, a large number of prismatic reflective grooves 14 are provided on the reflective surface 13 of the light guide member 10 according to the present embodiment. These reflective grooves 14 are formed along a direction (both

side surfaces

15 and 15 directions) orthogonal to the longitudinal direction of the light guide member 10 (opposite direction of the light source units 2 and 2) and along the longitudinal direction. It is provided at intervals. That is, these reflective grooves 14 are formed along a direction parallel to the incident surface 11 and are provided parallel to each other.

Further, these reflecting grooves 14 are provided substantially symmetrically with respect to the longitudinal center line 3. That is, the reflective grooves 14 are provided in a substantially line symmetrical manner with the longitudinal center line 3 as the axis of symmetry.

In the present embodiment, the reflecting groove 14 has a substantially V-shaped groove shape as shown in FIG. In the example shown in the figure, the reflective concave groove 14 is illustrated in a large size. However, in actuality, the reflective groove 14 is fine, for example, the groove width and the groove depth are of the order of micro order or millimeter order (FIG. 2). The same applies to the reflective ditch 14A in FIG. In addition, the pitch at which the reflective concave grooves 14 are provided at intervals along the longitudinal direction is also on the order of micro order or millimeter order.

Further, in the present embodiment, these reflective grooves 14 are configured to reflect the light from the

incident surfaces

11 and 11 toward the emission surface 12 so as not to diffuse along the longitudinal direction. In other words, the reflection concave grooves 14 are configured to reflect light emitted from the emission surface 12 toward the emission surface 12 so as to be close to a direction orthogonal to the emission surface 12. For example, as shown in FIG. 1 (b), in the front view, that is, the direction of the light beam reflected by the reflective groove 14 projected onto the plane area parallel to the both

side surfaces

15, 15 and the exit surface 12 form. The angle may be in the range of about 80 to 100 degrees.

As such a reflective groove 14, the angle formed by the reflective surface 13 where the reflective groove 14 is not provided and the groove reflective surface 14a of the reflective groove 14 where light is incident and reflected is defined as the reflective groove. What is necessary is just to set according to the incident angle of the light which injects into 14, the refractive index of the said light guide member 10, etc. FIG. The incident angle may be determined according to the refractive index, the dimension from the reflecting surface 13 to the exit surface 12, the dimension between both

incident surfaces

11, 11, the dimension between both

side surfaces

15, 15, and the like. .

In the illustrated example, the angle formed between the reflecting surface 13 where the reflecting groove 14 is not provided, that is, the plane that intersects the incident surface and is parallel to the emitting surface 12 and the groove reflecting surface 14a of the reflecting groove 14, An example of about 120 to 140 degrees is shown.

In the light guide member 10 configured as described above, as conceptually shown in FIG. 1B, light is guided while being repeatedly reflected in the light guide member 10, and is incident on the groove reflection surface 14 a of the reflective groove 14. The emitted light is reflected with its diffusion in the longitudinal direction being suppressed. Then, the light is emitted from the emission surface 12 in a direction close to a direction orthogonal to the emission surface 12.

In addition, the formation of the reflective grooves 14 is such that the shape of the reflective grooves 14 is formed on the transfer surface (cavity surface, slide core surface) of the mold when the light guide member 10 is formed by, for example, injection molding. It may be formed by forming a pattern corresponding to the above. Or after forming in a substantially prismatic shape, you may make it form the reflective ditch | groove 14 with cutting tools, such as a cutting tool.

According to the light guide member 10 and the light emitting device 1 including the light guide member 10 having the above-described configuration, the directivity of light emitted from the emission surface 12 can be improved while having a simple structure. .

That is, a large number of prismatic reflective grooves 14 along the direction orthogonal to the facing direction of the

light source units

2 and 2 are formed on the reflecting surface 13 of the light guide member 10 at intervals along the facing direction. They are provided substantially symmetrically with respect to the direction center 3. Therefore, the directivity of light emitted from the emission surface 12 can be improved. In other words, the light guided while being reflected in the light guide member 10 can be reflected in the direction along the opposing direction by the reflective grooves 14, thereby suppressing reflection in the direction orthogonal to the opposing direction. Therefore, the directivity of the light emitted from the emission surface 12 can be improved. As a result, the light emitted from the emission surface 12 is superimposed along the facing direction, and the illuminance on the irradiation target surface can be relatively improved.

Further, since the reflection concave grooves 14 are provided substantially symmetrically across the center 3 in the opposing direction, the

light source units

2 and 2 from the

light source units

2 and 2 arranged opposite to each other are improved while improving the directivity along the opposing direction. Light distribution control such as superimposing and uniforming light effectively can be realized with a simple structure. That is, the amount of light emitted from the emission surface 12 tends to decrease in a portion far from the light source unit 2. As in the present embodiment, the reflection concave grooves 14 are provided in a substantially symmetrical shape across the substantially center 3 in the opposing direction of the

light source units

2 and 2, so that the light is incident from the respective incident surfaces 11 and 11 and gradually emitted and attenuated. The light to be overlapped can be overlapped at the substantially central portion in the opposing direction, and insufficient illuminance at the central portion can be suppressed.

Furthermore, since the reflection pattern is formed by the reflection concave grooves 14 formed in the light guide member 10, a scattering dot is formed as in the prior art, or the reflection pattern is configured by another member such as a diffusion plate or a reflection plate. Manufacturing is relatively easy as compared to the above, and a simple structure can be achieved.

Further, in the present embodiment, the reflection concave groove 14 is configured to reflect the light from the incident surface 11 toward the output surface 12 so as not to diffuse along the facing direction. Therefore, the diffusion of the light emitted from the emission surface 12 in the opposite direction can be relatively suppressed, and the illuminance on the irradiation target surface can be improved even when the irradiation target is far away.

Further, the reflective ditch 14 has a length direction. The length direction of the reflective ditch 14 is defined as a direction orthogonal to the facing direction of the light source. Further, the length direction of the reflective ditch 14 is along the emission surface 12. The reflective groove 14 has a cross section along a direction orthogonal to the length direction of the reflective groove 14. The cross section of the reflective ditch 14 is formed in a V shape.

Thereby, the directivity of the light emitted from the emission surface 12 can be improved. Thereby, the light emitted from the emission surface 12 is superimposed along the facing direction. Therefore, the illuminance on the irradiation target surface can be relatively improved.

Further, the cross section of the reflective ditch 14 has a triangular shape, whereby the reflective ditch 14 is formed in a V shape. Therefore, the illuminance on the irradiation target surface can be relatively improved.

The cross section of the reflective ditch 14 may be trapezoidal. That is, the cross section of the reflective ditch 14 may have a triangular shape or a trapezoidal shape. Thereby, the reflective ditch | groove 14 is formed in V shape. Therefore, the illuminance on the irradiation target surface can be relatively improved.

Further, the reflective ditch 14 has an inner surface. The inner surface of the reflective concave groove 14 is defined as a groove reflective surface 14a. The angle formed by the surface parallel to the emission surface 12 and the groove reflecting surface 14a of the reflecting groove 14 is set to be 120 degrees or more and 140 degrees or less. Therefore, the illuminance on the irradiation target surface can be relatively improved.

Next, another embodiment according to the present invention will be described with reference to the drawings.

FIG. 2 is a conceptual explanatory diagram for explaining an example of the light guide member according to the second embodiment and a light emitting device including the light guide member.

Note that differences from the first embodiment will be mainly described, and the same components will be denoted by the same reference numerals, and description thereof will be omitted or briefly described.

In the light emitting device 1A according to the present embodiment, the configuration of the reflective surface 13A of the light guide member 10A is different from that of the first embodiment.

In the present embodiment, a large number of reflecting grooves 14A provided on the reflecting surface 13A are configured to reflect light in the direction in which light from the incident surfaces 11 and 11 is diffused obliquely along the longitudinal direction. In other words, the reflection concave grooves 14 </ b> A are configured to reflect light from one light source unit 2 so as to be obliquely directed toward the other light source unit 2. For example, as shown in FIG. 2B, the angle formed between the light emitting direction reflected by the reflecting concave groove 14A projected on the plane area parallel to both side surfaces 15 and 15 and the exit surface 12 is 50 degrees or more. The range may be about 80 degrees.

As described above, the reflection groove 14A has an angle formed between the reflection surface 13A where the reflection groove 14A is not provided and the groove reflection surface 14a of the reflection groove 14A where light is incident and reflected, as described above. What is necessary is just to set according to various factors. In the illustrated example, the angle formed by the reflecting surface 13A where the reflecting groove 14A is not provided, that is, the plane that intersects the incident surface and is parallel to the emitting surface 12 and the groove reflecting surface 14a of the reflecting groove 14A, An example of about 140 to 160 degrees is shown.

In the light guide member 10A configured as described above, as conceptually shown in FIG. 2 (b), light is guided while being repeatedly reflected in the light guide member 10A, and is incident on the groove reflection surface 14a of the reflective concave groove 14A. The emitted light is reflected in a direction in which it is diffused obliquely along the longitudinal direction. And the light from one light source unit 2 is radiate | emitted from the output surface 12 so that it may face diagonally toward the other light source unit 2 side.

The light guide member 10A according to the present embodiment configured as described above and the light emitting device 1A provided with the light guide member 10A have substantially the same effects as those of the first embodiment.

Further, in the present embodiment, the reflection concave groove 14A is configured to reflect light in a direction in which light from the incident surface 11 is diffused obliquely along the opposing direction. Therefore, the light emitted from the emission surface 12 is diffused obliquely along the facing direction, and a relatively wide range can be irradiated even when the irradiation target is close.

In addition, in each said embodiment, although the example which made the light guide member 10 (10A) conceptually a substantially rectangular parallelepiped shape is shown, it is not restricted to such an aspect. For example, it is good also as a lens shape which can condense the light from a light source in the longitudinal direction both ends by which the

light source units

2 and 2 are arrange | positioned. Further, the both side surfaces 15 and 15 are expanded from the reflection surface 13 (13A) toward the emission surface 12 so that the diffusion of light in the direction orthogonal to the opposing direction (the both side surfaces 15 and 15 direction) can be further reduced. You may form in the inclined shape (taper shape) which opens. Furthermore, the exit surface 12 may be a convex curved surface so that the diffusion of light in the direction orthogonal to the opposing direction can be further reduced.

In the illustrated example, a light beam emitted from a point light source is illustrated, but the present invention is not limited to such a mode. For example, a plurality of LEDs may be arranged in parallel in the direction from the reflecting surface 13 (13A) toward the emitting surface 12 (the vertical direction in FIGS. 1B and 2B).

Furthermore, although the example shown as the elongate rod-shaped light guide member 10 (10A) is shown in the figure example, as the substantially flat plate-shaped light guide member 10 (10A) formed largely along both side surfaces 15 and 15 directions. Also good. In this case, a plurality of LEDs or light source units 2 may be arranged in parallel along both side surfaces 15 and 15.

Furthermore, the light source is not limited to the LED, and an incandescent lamp, a discharge lamp, and other light sources may be adopted.

In the illustrated example, each of the reflection concave grooves 14 (14A) has a substantially inverted isosceles triangle shape, but is not limited to such a shape, and may have another inverted triangle shape or a substantially inverted trapezoidal shape. In particular, when the dimension between the

light source units

2 and 2 is sufficiently longer than the dimension from the reflection surface 13 (13A) to the emission surface 12, the light from each

light source unit

2 and 2 is opposed to the opposite direction. There is a tendency that the light is reflected from the reflection concave groove 14 (14A) provided on the light source unit 2 side and the other reflection surface (side surface, etc.) and emitted from the emission surface 12 before reaching the center portion. is there. Therefore, in such a case, the shape and angle of the groove surface on the side different from the groove reflection surface of the reflection concave groove 14 (14A) (the groove surface on the center side in the opposing direction) may be any.

In the illustrated example, the reflective surface 13 (13A) not provided with the reflective concave grooves 14 (14A) is illustrated as being substantially coplanar. However, the present invention is not limited to such an embodiment. For example, the reflection surface 13 (13A) is an inclined surface that is inclined toward the emission surface 12 toward the center in the opposite direction so that the illuminance deficiency at the central portion in the opposite direction can be more effectively reduced. It is good also as an aspect which forms a reflective ditch | groove.

Furthermore, in each said embodiment, although the example which made the groove shape of each reflective ditch | groove 14 and 14A substantially the same shape was shown, it is not restricted to such an aspect. For example, it is good also as an aspect which makes the groove depth of a reflective ditch | groove deeper toward the opposing direction center so that the illumination intensity shortage in the opposing direction center part can be reduced more effectively.

Furthermore, in each said embodiment, although the example which made the pitch which provides each reflective ditch | groove 14 and 14A substantially the same pitch along the opposing direction is shown, it is not restricted to such an aspect. For example, it is good also as an aspect which provides the reflective ditch | groove 14 (14A) so that it may become dense as it goes to the opposing direction center so that the illumination intensity shortage in the opposing direction center part can be reduced more effectively.

As described above, the light guide member 10 shown in FIG. 2 has the same configuration as the light guide member 10 shown in FIG. Therefore, also in the light guide member 10 shown in FIG. 2, the same effect as the light guide member 10 shown in FIG. 1 is acquired.

Further, the reflective ditch 14 has an inner surface. The inner surface of the reflective concave groove 14 is defined as a groove reflective surface 14a. The angle formed by the surface parallel to the emission surface 12 and the groove reflection surface 14a of the reflection concave groove 14 is set to 140 degrees or more and 160 degrees or less. Therefore, the illuminance on the irradiation target surface can be relatively improved.

Therefore, when the light guide member 10 of FIG. 1 and the light guide member 10 of FIG. 2 are taken into consideration, the angle formed between the surface parallel to the emission surface 12 and the groove reflection surface 14a of the reflection groove 14 is 120 degrees or more and 160. It can be set to below the degree.

It should be noted that the angle formed between the surface parallel to the emission surface 12 and the groove reflection surface 14a of the reflection groove 14 is not limited to 120 degrees or more and 160 degrees or less. The angle formed by the surface parallel to the emission surface 12 and the groove reflecting surface 14a of the reflecting groove 14 is appropriately determined according to the application.

1,1A Light-emitting device 2 Light source unit (light source)
3 Longitudinal center line (opposite center)
10, 10A Light guide member 11 Entrance surface 12

Output surface

13,

13A Reflection surface

14, 14A Reflection ditch

Claims

A light guide member that is disposed between light sources disposed opposite to each other, guides light incident from the incident surfaces of both end surfaces, and emits light from an emission surface provided to intersect the incident surface,
A large number of prismatic reflective grooves along the direction orthogonal to the facing direction of the light source are spaced along the facing direction on the reflecting surface provided on the opposite side of the emitting surface so as to intersect the incident surface. And a light guide member provided symmetrically with respect to the opposite direction center.
In claim 1,
The light guide member, wherein the reflection concave groove of the reflection surface is configured to reflect the light from the incident surface toward the emission surface so as not to diffuse along the facing direction.
In claim 1,
The light guide member, wherein the reflection concave groove of the reflection surface is configured to reflect light from the incident surface in a direction in which the light is diffused obliquely along the facing direction.
The reflective ditch has a length direction;
The length direction is defined as a direction orthogonal to the facing direction of the light source,
The reflective ditch has a cross section along a direction perpendicular to the length direction,
The light emitting device according to any one of claims 1 to 3, wherein the cross section is formed in a V shape.
5. The light emitting device according to claim 4, wherein a cross-section of the reflection ditch has a triangular shape, whereby the reflection ditch is formed in a V shape.
A light-emitting device comprising: the light guide member according to any one of claims 1 to 5; and a light source disposed opposite to both end faces of the light guide member.