JPH11283424A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve luminance, to reduce a replacing labor, and to clearly perform illumination even under the sunlight by forming the parallel groove parts in a plurality on the reverse of a light conductive plate to which a condensing fluorescent dye is added, and arranging a light emitting diode between this and a reflecting plate oppositely arranged on the reverse. SOLUTION: A light conductive plate 2 by adding a condensing fluorescent dye to an excellently light transmissive resin such as acrylic is arranged inside a transparent glass pane 6 arranged in the opening part 8 of a casing 7, a reflecting plate 9 is oppositely arranged on the reverse 4, and a light emitting diode 10 is arranged between them. The parallel saw shaped groove parts 5 are formed in a plurality on the reverse 4 of the light conductive plate 2. The direct incident light 15 from a light emitting element 11 of the light emitting diode 10 is incident from an inclined face 19 of the groove parts 5 to mostly become the direct refracted light 18, and the indirect incident light 20 from the reflecting plate 9 is also incident from an inclined face 23 of the groove parts 5 to mostly become the indirect refracted light 22 to emit the light by respectively efficiently exciting a fluorescent dye. Therefore, the emitting light from the surface 3 of the light conductive plate 2 is increased to enhance luminance of a lighting system 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a lighting device.

[0002]

2. Description of the Related Art Conventionally, this type of apparatus is disclosed in, for example,
-281541. According to this publication, a fluorescent lamp is arranged near an end surface of a light guide plate made of a flat plate, and the light of the fluorescent lamp is guided to the light guide plate to illuminate a liquid crystal display device above the light guide plate.

[0003]

However, in the above-described device, various improvements have been made only by seeking uniformity of luminance over the entire surface of the light guide plate. Therefore, although uniform luminance is obtained, the luminance itself is low. Therefore, there is a first disadvantage that the brightness is low as a lighting device installed along the road in the tunnel, and the driver is hard to notice. In order to solve this problem, it is conceivable to install a plurality of fluorescent lamps, but there is a second disadvantage that it requires time and effort to replace the fluorescent lamps periodically.

[0004] Furthermore, these lighting devices have a third drawback in that the lighting is difficult to see in places where sunlight enters, such as at the entrance or exit in a tunnel. Therefore, the present invention has been made in view of such conventional drawbacks, and provides an illuminating device which has a high luminance, requires less labor for replacement, and can clearly illuminate even under sunlight.

[0005]

According to a first aspect of the present invention, there is provided a light guide plate to which a light-collecting fluorescent dye is added and which emits fluorescence by incident light. A light-emitting diode is disposed between the reflector and the light guide plate, and a groove is provided on the back surface of the light guide plate.

Preferably, the light guide plate is formed to be long, and a plurality of grooves are provided so as to extend in parallel with the long direction.

[0007] Preferably, the groove is formed in a saw-like shape, or a saw-like portion and a flat portion are formed alternately.

Preferably, a plurality of light emitting diodes are arranged so as to be substantially perpendicular to the extending direction of the groove.

According to a second aspect of the present invention, there is provided a light guide plate to which a light-harvesting fluorescent dye is added and which emits fluorescence by incident light, a reflection frame exposing the surface of the light guide plate and surrounding the rear surface, and facing the rear surface of the light guide plate. And a light emitting diode arranged in a reflection frame to emit light.

Preferably, the light emitting diode is arranged so that the optical axis of the light emitting diode obliquely intersects the light guide plate, and a reflecting plate positioned substantially parallel to the optical axis is provided in the reflecting frame.

[0011] Preferably, the light guide plate is formed in a long shape, and a groove is provided at an appropriate position in the long shape.

Preferably, the light guide plate is constituted by a plurality of light guide plates, and the light guide plate ends are overlapped with each other.

Preferably, according to the transmittance for each color of the light guide plate,
This is for selecting the emission color of the light emitting diode.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a lighting device 1 according to a first embodiment of the present invention will be described with reference to a front view of FIG. 1 and FIG. 2 showing an AA cross section of FIG. In these figures, the light guide plate 2 is made of, for example, a straight plate and is made of a resin having good transparency, for example, acryl, polycarbonate, polystyrene or the like, to which a condensing fluorescent dye is added.

When light enters the light guide plate 2 from the front surface 3 or the rear surface 4, the light is repeatedly reflected between the front surface 3 and the rear surface 4 by the condensing fluorescent dye to convert the incident light into fluorescent light. Things. A plurality of grooves 5 are formed on the back surface 4 of the light guide plate 2 so as to extend parallel to the long direction. The groove 5 is desirably formed in a continuous saw shape.

For example, a transparent plate 6 made of tempered glass or the like
It is arranged in front of the surface 3 of the light guide plate 2. The casing 7 is made of, for example, a metal plate, is formed in a substantially box shape, has an opening 8 formed in the front surface, and is configured to expose the transparent plate 6.

The reflection plate 9 is, for example, a metal plate or a resin painted white, formed in an inverted L-shape, and arranged to face the back surface 4 of the light guide plate 2. That is, the reflection plate 9 is fixed along the inner surface of the casing 7. Note that the casing 7 may be divided into two parts and the parts may be fixed to each other.

The light emitting diode 10 is, for example, a light emitting element 11 made of gallium phosphide or the like mounted on a lead frame (not shown) and covered with a resin 12.
For example, it emits red light. As shown in FIG. 2, the light emitting diode 10 is disposed between the reflection plate 9 and the light guide plate 2. Also, as shown in FIG.
Are arranged at predetermined intervals such that the central optical axis 13 (the light emission direction in which the luminance is maximized) is substantially orthogonal to the extension direction 14 of the groove 5 formed in the light guide plate 2.

The light guide plate 2 is of a red type, an orange type, a yellow type, or a purple type.
High transmittance by color for yellow and purple. Therefore, if the red light emitting diode 10 is selected as the light source of the red light guide plate 2, the light transmittance is high and the fluorescent light can be efficiently emitted. Similarly, if the light guide plates 2 of the orange, yellow, and violet types are also made to emit light by light emitting diodes of the same color, fluorescent light can be efficiently emitted. The lighting device 1 is configured by these components.

Next, the operation of the illumination device 1 will be described again with reference to FIGS. The leftward light emitted from the light emitting diode 10 reaches the groove 5 of the light guide plate 2 as direct incident light 15. Part of the direct incident light 15 is directly reflected light 16.
Then, the process proceeds to a closed region 17 surrounded by the light guide plate 2 and the reflection plate 9. Further, a part of the direct incident light 15 becomes a direct refracted light 18, enters the inside of the light guide plate 2, is converted into fluorescent light by a condensing fluorescent dye, and is emitted from the surface 3 of the light guide plate 2. The emitted light passes through the transparent plate 6, passes through the opening 8, and is emitted to the outside of the lighting device 1.

As described above, by providing the groove portion 5 on the back surface 4 of the light guide plate 2, even on the back surface 4 located far from the light emitting diode 10, the direct incident light 15 can be formed on the inclined surface 19 of the groove portion 5.
To reach. As a result, the direct incident light 15 has a smaller incident angle with respect to the inclined surface 19, so that total reflection does not occur as in the related art. Therefore, the amount of the direct refracted light 18 increases, and the light emitted from the surface 3 of the light guide plate 2 increases, so that the luminance increases.

Desirably, the groove 5 is formed in a sawtooth shape so that the direct incident light 15 is incident on the inclined surface 19 of the groove 5 at an angle close to a right angle. As a result, the amount of the direct refracted light 18 increases, and the luminance increases.

The rightward light emitted from the light emitting diode 10 is reflected by the reflector 9 and reaches the groove 5 of the light guide plate 2 as indirectly incident light 20. And the indirect incident light 20 is 1
The portion becomes the indirect reflected light 21 and proceeds to the closed area 17.

A part of the indirectly incident light 20 becomes indirectly refracted light 22, enters the inside of the light guide plate 2, is converted into fluorescent light by a condensing fluorescent dye, and is emitted from the surface 3 of the light guide plate 20.
The light is emitted to the outside of the lighting device 1 through the transparent plate 6, the opening 8.

As described above, by providing the groove 5 on the back surface 4 of the light guide plate 2 (preferably, the groove 5 is formed in a saw-like shape),
The indirect incident light 20 reaches the inclined surface 23. As a result, since the incident angle of the indirect incident light 20 with respect to the inclined surface 23 becomes small, total reflection does not occur, and the amount of the indirect refracted light 22 increases,
The brightness of the lighting device 1 increases.

The present inventor has manufactured a groove 5 provided on the back surface 4 of the light guide plate 2 into a groove extending perpendicular to the longitudinal direction of the light guide plate 2, a groove extending in parallel with the light guide plate 2, and a groove extending obliquely.
Experimented. As a result, it was found that the one in which the plurality of grooves 5 were formed so as to extend in parallel with the longitudinal direction of the light guide plate 2 had the highest luminance.

Further, the central optical axis 13 of the light emitting diode 10
It is desirable to arrange a plurality of light emitting diodes 10 such that the light emitting diodes 10 are substantially perpendicular to the extending direction 14 of the groove 5. With this configuration, the incident angles of the direct incident light 15 and the indirect incident light 20 with respect to the inclined surfaces 19 and 23 are smaller than those in the case where the central optical axis 13 is oblique in the extension direction 14. . As a result, the amounts of the direct refracted light 18 and the indirect refracted light 22 increase, and the luminance of the illumination device 1 increases.

Further, as a result of the experiment, the luminance distribution has a maximum luminance at a viewing angle of ± 42.2 °. This is considered to be due to the fact that when the material of the light guide plate 2 is acrylic, the critical angle is 42.2 ° due to the refractive index of acrylic 1.49.

For example, when the illuminating device 1 is installed so as to illuminate white lines provided on both sides of a road in a tunnel, the maximum brightness is obtained when the viewing angle is ± 42.2 °. The driver of the car that comes in
It is easy to notice the white line that peaks at a viewing angle of 42.2 °, and the driver of a car traveling from the opposite lane is + 42.2 °.
It is easy to notice a white line having a peak at the viewing angle of. Thus, visibility from both sides is good.

Next, a light guide plate 24 used in a lighting device according to a second embodiment of the present invention will be described with reference to the sectional view of FIG. In FIG. 3, the groove 25 has a saw-like portion 26 and a flat portion 27.
Are alternately formed. Thus, the flat portion 27
Is provided, the saw-shaped portion 26 is not damaged when the light guide plate 24 is handled. When the groove 25 is cut from a flat plate, unlike the groove 5 of the light guide plate 2 used in the lighting device 1, it is not necessary to cut deeply, so that the manufacturing can be more easily performed and the manufacturing cost is reduced.

Next, a lighting device according to a third embodiment of the present invention will be described with reference to a plan view of FIG. 4A and a sectional view of FIG. 4B. In these figures, the light guide plate 31 is, for example, a long rectangular parallelepiped, and is formed by adding a light-collecting fluorescent dye to a resin having good transparency, for example, acryl, polycarbonate, polystyrene, or the like.

The light guide plate 31 has a front surface 32 or a back surface 33.
When the light enters from above, the light-collecting fluorescent dye is totally reflected inside the front surface 32 and the inside of the back surface 33, and converts the incident light into fluorescent light. The light is emitted from the lower end face 35, the right end face 36, and the left end face 37.

The reflection frame 38 is made of, for example, an iron plate or a resin painted in white, and has an inner surface having reflectivity. The reflection frame 38 is viewed from a plane (FIG. 4).
(See (a)) It is formed in a frame shape having an opening 39, and when viewed from a cross section (see FIG. 4B), it is formed in a substantially U-shape. In this way, the reflection frame 38 holds the light guide plate 31 so as to expose the front surface 32 of the light guide plate 31 and surround the back surface 33.

The reflecting plate 40 is, for example, a steel plate or a resin painted white, has a reflective property, and is fixed from the upper left corner to the lower right corner of the reflecting frame 38. The light emitting diode 42 is made of, for example, gallium phosphide, emits red light, and is disposed on the base 43 via a circuit board (not shown). A plurality of light emitting diodes 42 are fixed on the circuit board at predetermined intervals along the longitudinal direction of the light guide plate 31, and are wired on the circuit board.

The light from the light emitting diode 42 is applied to the light guide plate 31.
Is radiated toward the back surface 33. Preferably, the light emitting diode 42 is arranged obliquely with respect to the bottom surface of the reflection frame 38 such that the optical axis 44 of the light emitting diode 42 is oblique to the light guide plate 31. Further, the reflection plate 40 is arranged so as to be located substantially parallel to the optical axis 44.

According to the experiment of the present inventor, when the optical axis 44 of the light emitting diode 42 is perpendicularly applied to the light guide plate 31, the light from the light emitting diode 42 hits the light guide plate 31 as a point light source, and Becomes spot-like, and the end face 34,
It was found that light emission at 35, 36 and 37 was reduced.
Therefore, it is better that the optical axis 44 is oblique to the light guide plate 31. Further, by making the reflecting plate 40 substantially parallel to the optical axis 44, light 45 emitted to the right from the light emitting diode 42 hits the reflecting plate 40, the reflected light hits the light guide plate 31, and the amount of light condensed on the light guide plate 31 Was found to increase.

Further, the light guide plate 31 is of a red type, an orange type,
There are yellow and purple types, and the transmittance for each color is higher for red, orange, yellow, and purple, respectively. Therefore, the red light emitting diode 42 is used as a light source of the red light guide plate 31.
Is set, the light transmittance is high and the fluorescent light can be emitted efficiently. Orange type, yellow type, purple type light guide plate 31
Similarly, when light is emitted by light emitting diodes of the same color, fluorescent light can be emitted efficiently.

Next, the operation of the illumination device 46 will be described again with reference to FIG. Leftward light 4 from light emitting diode 42
7 and light along the optical axis 44 are directly transmitted to the back surface 33 of the light guide plate 31.
Hit. Rightward light 45 from the light emitting diode 42 is reflected by the reflector 40 and then strikes the back surface 33.

Light entering from the back surface 33 of the light guide plate 31 is converted into fluorescent light by a light-collecting fluorescent dye, and is converted into fluorescent light by the front surface 32 and the back surface 33.
, The total reflection is repeated, and most of the light amount is emitted from the end faces 34, 35, 36, and 37. As a result, the end faces 34, 3
High-intensity fluorescent light is obtained in the vicinity of 5, 36, and 37. When a plurality of the illuminating devices 46 are arranged side by side along a road in a tunnel, the driver emits light in the form of a long and narrow track to provide clear lighting to the driver. give.

Further, in the lighting device 46, the light emitting diode 4
2 and a long service life, which eliminates the need for regular replacement as in the case of conventional fluorescent lamps. Also, even if sunlight enters like an entrance or an exit in a tunnel, sunlight 48 is applied to the light guide plate 31.
And the brightness of the end faces 34, 35, 36, and 37 is increased, and high brightness is obtained without the sunlight interfering with the illumination as in the related art.

Next, a lighting device 50 according to a fourth embodiment of the present invention will be described with reference to a plan view of FIG. 5A and a sectional view of a light guide plate 51 of FIG. In these figures, a groove 52 (for example, V-cut, etc.)
Is formed. Light entering the light guide plate 51 from the light emitting diode 42 is emitted to the outside through the groove 52, and high brightness is obtained near the groove 52. As described above, the plurality of grooves 52 formed in the light guide plate 51 provide high brightness, and thus the lighting device 50 gives an impression of high brightness as a whole. Other parts are shown in FIG.
Is the same as

Next, a lighting device 54 according to a fifth embodiment of the present invention will be described with reference to a plan view of FIG. 6A and a cross-sectional view of a light guide plate 55 of FIG. In these figures, the light guide plate 55 has a plurality of light guide plates 56, 57, 58, 59 superimposed and provided with superposed portions 60, 61, 62.

The light guide plate 5 at the overlapping portion 60
Rightward light C is emitted from each of the end faces 6, 57, 58 and 59, and leftward light D is emitted from the light guide plates 56, 57, 58 and 59. As a result, the luminance becomes high in the overlapping portion 60, and the lighting device 54 gives the impression of high luminance as a whole. The other components are the same as those in FIG. In addition, the light guide plates 31, 51, 55 or the reflection plate 40
A pattern, character, or the like can be attached with various paints, stickers, or the like, and this can be used as a means for transmitting information.

Further, the present invention is not limited to lighting in a tunnel, and may be used indoors or outdoors regardless of day or night, such as traffic signs, gaze guide signs, road tacks, road supplies in parking lots, signboards, billboards, and guide signs. Can respond to the environment.

[0045]

As described above, according to the first aspect of the present invention, there is provided a light guide plate to which a light-harvesting fluorescent dye is added and which emits fluorescence by incident light, a reflector, and a light emitting diode. Is provided with a groove. As a result, the incident angle of the direct incident light and the indirect incident light becomes smaller with respect to the inclined surface of the groove, the light amount of the direct refraction light and the indirect refraction light increases, and the emission light from the surface of the light guide plate increases. Brightness increases.

According to a second aspect of the present invention, the light guide plate is formed to be long, and a plurality of grooves are provided so as to extend in parallel with the long direction.
As a result of the experiment, a light guide plate having a plurality of grooves provided in parallel in the long direction can obtain higher luminance than a light guide plate extending at a right angle or an obliquely extending one.

According to the third aspect of the present invention, the grooves are formed in a sawtooth shape, so that the direct incident light and the indirect incident light are incident on the inclined surface of the groove at an angle close to a right angle. As a result, the amounts of the direct refraction light and the indirect refraction light increase, and the luminance increases. By forming the groove portions by alternately forming the saw-like portions and the flat portions and setting the flat portions, it is possible to prevent the saw-like portions from being damaged when the light guide plate is handled.

According to a fourth aspect of the present invention, a plurality of light emitting diodes are arranged so that the central optical axis of the light emitting diodes is substantially perpendicular to the extending direction of the groove. By configuring in this way,
The incident angles of the direct incident light and the indirect incident light with respect to the respective inclined surfaces are smaller than in the case where the central optical axis obliquely extends in the extension direction. As a result, the amount of the direct refraction light and the indirect refraction light increases, and the luminance further increases.

According to a fifth aspect of the present invention, the light from the light emitting diode enters from the back surface of the light guide plate, is converted into fluorescent light by the light-collecting fluorescent dye, and is repeatedly totally reflected on the front surface and the back surface. Released. Therefore, high brightness is obtained at the end face and visibility is improved. In addition, since the light emitting diode is used, the life is long and the trouble of periodically replacing the lamp like a conventional fluorescent lamp can be omitted. Furthermore, even if sunlight or light from an automobile lamp is incident on the surface of the light guide plate, the light is totally reflected within the light guide plate and emitted from the end face, so that the brightness of the end face is further improved.

According to a sixth aspect of the present invention, light from a light emitting diode is prevented from impinging on the light guide plate in a spot-like manner by obliquely intersecting the optical axis of the light emitting diode with the light guide plate, and the light guide plate is efficiently illuminated. Incident. Further, the light on the right side of the light emitting diode is reflected by the reflector parallel to the optical axis and is incident on the light guide plate, so that the amount of incident light increases.

According to the seventh aspect of the present invention, by providing a groove at an appropriate position on the long side of the light guide plate, the amount of light emitted from the groove to the outside is increased, and high brightness is obtained in the groove. .

According to the present invention, the light guide plate is composed of a plurality of light guide plates, and the end portions of the respective light guide plates are overlapped. As a result, high brightness is obtained at the overlapping portion of the end portions, and high brightness is obtained as the entire lighting device.

According to the ninth aspect of the present invention, the luminescent color of the light emitting diode is selected according to the transmittance of each color of the light guide plate, so that the selected luminescent color efficiently enters the light guide plate and the amount of incident light increases.

[Brief description of the drawings]

FIG. 1 is a front view of a lighting device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view of a light guide plate used in a lighting device according to a second embodiment of the present invention.

FIG. 4A is a plan view of a lighting device according to a third embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along a line BB of FIG. 4A.

FIG. 5A is a plan view of a lighting device according to a fourth embodiment of the present invention, and FIG. 5B is a cross-sectional view of a light guide plate used in the above device.

FIG. 6A is a plan view of a lighting device according to a fifth embodiment of the present invention, and FIG. 6B is a cross-sectional view of a light guide plate used in the device.

[Explanation of symbols]

 2 light guide plate 5 groove 9 reflector 10 light emitting diode

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuhisa Yuza 320-1, Yamagata, Kiji-cho, Ohara-gun, Shimane Prefecture Shimane Sanyo Kogyo Co., Ltd.

Claims (9)

[Claims] 1. A light guide plate to which a light-collecting fluorescent dye is added and which emits fluorescence by incident light, a reflector disposed opposite to a back surface of the light guide plate, and a light guide plate including the light guide plate and the light guide plate. A lighting device comprising: a light emitting diode disposed therebetween; and a groove provided on a back surface of the light guide plate. 2. The lighting device according to claim 1, wherein the light guide plate is formed to be long, and the plurality of grooves are provided so as to extend in parallel with the long direction. 3. The lighting device according to claim 2, wherein the groove is formed in a saw-like shape, or the saw-like portion and the flat portion are alternately formed. 4. The lighting device according to claim 2, wherein a plurality of the light emitting diodes are arranged so as to be substantially orthogonal to an extending direction of the groove. 5. A light guide plate to which a light-collecting fluorescent dye is added to emit fluorescence by incident light, a reflection frame exposing a surface of the light guide plate and surrounding the rear surface, and emitting light toward the rear surface of the light guide plate. And a light-emitting diode disposed in the reflection frame. 6. The light-emitting diode is disposed so that an optical axis of the light-emitting diode is oblique to the light guide plate, and a reflection plate positioned substantially parallel to the optical axis is provided in the reflection frame. The lighting device according to claim 5, wherein: 7. The lighting device according to claim 5, wherein the light guide plate is formed to be long, and a groove is provided at an appropriate position of the long plate. 8. The lighting device according to claim 5, wherein the light guide plate is constituted by a plurality of light guide plates, and the ends of the light guide plates are overlapped. 9. The lighting device according to claim 1, wherein a light emission color of the light emitting diode is selected according to a transmittance of each color of the light guide plate.