JP2857974B2 - Road luminous sign device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminous sign device for roads used for displaying a center separation line, a no-passing line, a stop line, etc. on a road.

[0002]

2. Description of the Related Art It is well known that a light emitting diode of this type uses a light emitting diode as a light source and turns it on at night with a storage battery charged with a solar cell as a power supply. . Usually, a light source, a solar cell, a storage battery, and a control circuit necessary for lighting are housed in a translucent case. Conventionally, in order to allow light from a light source to be directly visible to a driver or a pedestrian, the case is installed so that the surface of the case protrudes from a road surface.

[0003] Specifically, the case is configured such that the surface of the case protrudes from the road surface, and an inclined surface that is inclined obliquely upward is formed on the periphery of the case. Light obliquely upward from the light source goes straight on a plane portion orthogonal to the optical axis of the light, and goes to an inclined surface, where it is refracted and goes out. At this time, it is possible to bend in an upward direction with respect to the road surface due to the inclination of the inclined surface.

However, according to this configuration, since the inclined surface is provided between the surface of the case and the road surface, the inclined surface becomes a step and the case surface and the road surface are discontinuous. Therefore, impacts and noises are generated by vehicles passing over the case surface, and vehicles riding on this roll over,
Pedestrians may trip. Also, due to the formation of an inclined surface on the periphery of the case, this surface must be square, so a ridge line is created between the inclined surfaces formed on its adjacent sides, so that adjacent inclined surfaces become discontinuous, Rollover of the vehicle and stumbling of the pedestrian become even more remarkable.

In order to solve this problem, it is conceivable to configure the surface of the case so as to substantially coincide with the road surface. With this configuration, the light source is located below the road surface. Therefore, it is necessary to extract light from a light source located below the road surface onto the road surface at an angle as low as possible. The case of such a configuration will be discussed with reference to FIG.

In FIG. 5, P is a side wall of the case, and Q is a front cover (light transmissive) of the case. It is assumed that light is incident on the back surface A of the front cover Q from the light source L at an incident angle i and is refracted at a refraction angle r.
The light that has passed through the inside of the front cover Q is refracted again by the surface B of the front cover Q and goes to the outside. At this time, the incident angle with respect to the surface B is r, and the refraction angle is i. The light heading to the outside (the angle of the light with respect to the surface B, that is, the elevation angle is a).
Is visually recognized by pedestrians and drivers.

If the eyes of a pedestrian are about 150 cm, the eyes of a driver of a passenger car are about 120 cm, and the eyes of a driver of a large truck are about 230 cm, this luminescent sign 20 m ahead is provided. In order for the optical axis from to reach these human eyes, the elevation angle a needs to be 4-5 degrees.

Here, it is assumed that the front cover Q is made of a translucent acrylic resin. The refractive index n of the acrylic resin is 1.5
0, the critical angle is 41.8 degrees. To set the elevation angle a to 5 degrees, the incident angle i may be set to 85 degrees, and the refraction angle r at this time is 41.6 degrees.

It is also assumed that the front cover Q is made of a translucent polycarbonate resin. The refractive index n of the polycarbonate resin is 1.58 to 1.587, and the critical angle is 39.3 degrees. To set the elevation angle a to 5 degrees, the incident angle i is set to 8
The angle of refraction r at this time may be 39.1 degrees or more.
38.9 degrees.

As described above, both the acrylic resin and the polycarbonate resin can emit light having an elevation angle of 5 degrees from the front surface B. However, when the incident angle i is 85 degrees, the reflectance on the back surface A becomes 65% or more. Angle of refraction (surface B
Is the incident angle. ) Since r is very close to the critical angle, the reflection on the surface B is large, so that strong light cannot be obtained, and there is a possibility that a total change is caused by a slight change in the incident angle.

In order to avoid such a state, it is conceivable to set the elevation angle a to about 10 degrees. However, in this case, the incident angle i is 80 degrees, and the loss at the back surface A is 40 degrees. %. Also, the optical axis is directed toward the pedestrian or the driver. That is, in such a conventional structure, if the elevation angle is reduced, the loss of light due to reflection is large, and there is a risk of causing total reflection. On the other hand, if the elevation angle is increased to avoid this inconvenience, it becomes difficult for a driver or the like to visually recognize light.

[0012]

According to the present invention, even when a case containing a light source or the like is buried in a road so that its surface almost matches the road surface, the light from the light source is transmitted to a driver or the like. It is an object of the present invention to prevent a reduction in the amount of light radiated outward by making the angle at a low angle with respect to a road surface so as to make it easy to visually recognize and suppressing internal reflection.

[0013]

According to the present invention, there is provided a disk-shaped case having a light source comprising a solar cell, a storage battery and a light-emitting diode therein, wherein a circular-shaped front cover is made translucent, and the front cover is provided. And the light source is arranged so that the optical axis thereof is inclined with respect to the surface of the front cover portion, and further, on the back surface of the front cover portion, facing the light source, and the light source By providing a plane portion substantially orthogonal to the optical axis, light from the light source travels substantially straight toward the surface of the front lid portion through the flat portion, The case is buried in the road such that the outer peripheral edge substantially coincides with the road surface.

[0014]

The light from the light source is incident on the flat surface on the back surface of the front cover almost at right angles. As a result, almost no reflection occurs when light enters the front cover, and bright light can be obtained. Light travels straight through the inside of the front cover. Then, when the light is emitted from the surface of the front lid to the outside, the light is refracted. Since the optical axis of the light source is inclined with respect to the surface of the front cover, and since the surface of the front cover is spherical, due to this refraction, light is smaller than when the front cover is flat. Elevation angle. Therefore, even if the peripheral edge of the front cover portion is made substantially coincident with the road surface, the elevation angle can be reduced without a stepped portion being formed therebetween.

[0015]

FIG. 1 shows an embodiment of the present invention.
Reference numeral 1 denotes a case, which is formed in a disk shape by a synthetic resin such as an acrylic resin or a polycarbonate resin. And a circular front cover 2 serving as a surface of the case 1.
Is at least transparent or translucent such as translucent. The entire surface 2A of the front cover 2 is spherical. Reference numeral 3 denotes a back cover, and the inside of the case 1 is kept airtight by the back cover 3.

Inside the case 1, there are provided a solar cell 4, a storage battery 5 which is charged by using the solar cell 4 as a power source, and a light source 6 composed of a light emitting diode which is turned on using the storage battery 5 as a power source. Reference numeral 7 denotes a mounting frame for the light source 6. Although a charging circuit, a lighting circuit, a control circuit, and the like are separately housed in the case 1, they are omitted in the figure. The above configuration is not particularly different from the conventional configuration.

According to the present invention, the light source 6 is disposed so that its optical axis is inclined with respect to the surface 2 A of the front cover 2. In the illustrated example, the optical axis is arranged so as to be inclined toward the outer periphery of the case 1. And on the back of the front lid 2,
The flat portion 8 substantially orthogonal to the optical axis of the light source 6
It is formed so as to face.

More specifically, when a plurality of light sources 6 are arranged in a straight line in parallel with the diameter of the case 1 as shown in FIG. 2, the flat portion 8 also extends in parallel with the diameter of the case 1. Formed. The example of the figure shows a configuration in which a plurality of light sources 6 are arranged side by side symmetrically about the diameter of the case 1 on the left and right sides. The case 1 is buried in the road 11 such that the outer peripheral edge 2B of the front cover 2 substantially matches the road surface 10.

In the above configuration, first, the light from the light source 6 is incident on the plane portion 8 almost orthogonally. For this reason, the light travels straight on the plane portion 8 with little reflection. Therefore, at the time of incidence on the back surface of the front cover part 2, light loss hardly occurs, and even if it occurs, it is extremely small, about several percent. Then, the light is refracted on the surface 2 </ b> A of the front cover 2 and radiated to the outside. The refraction direction is a direction toward the outer periphery of the case 1.

Since the surface 2A of the front cover 2 is spherical, light exits at an angle i with respect to the normal N of the radiation surface (see FIG. 4). When the road surface is inclined by θ degrees with respect to the normal line N ′ (vertical line), the radiation optical axis is also inclined by θ degrees. This will be described in detail as follows. The light from the light source 6 goes straight and reaches the spherical surface of the front cover 2. This point is designated as C.

The direction of light is at an angle r with respect to the vertical line N 'at point C. If the surface of the front lid is flat, the emitted light travels in the direction shown by the broken line at an angle i with the normal N '.
However, since the surface of the front lid is spherical, the normal to the point C is not the normal N 'perpendicular to the road surface, but a straight line N connecting the point C and the center of the spherical surface.

The magnitude of the angle θ formed by the normal line N and the normal line N 'differs depending on the position on the spherical surface, but the normal line N is always outside the normal line N'. Since there is no change in the law of refraction, light is emitted from the point C not in the direction of the broken line but in the direction of the solid line that forms an angle θ therewith. In other words, when the radiation surface is spherical, it is possible to extract a light beam having a small elevation angle from the optical axis having the same angle r with respect to the vertical line. It will also be understood from this that light with a small elevation angle can be emitted without making the incident angle r so close to the critical angle.

When the surface of the front cover 2 is spherical, the normals N at the respective positions are not parallel to each other depending on the position where the light from the light source 6 hits the surface of the front cover 2. Therefore, the emitted light is scattered over a wide range, and the visual recognition becomes easy.

When the surface has a spherical shape, if the curvature of the spherical surface is large, the protrusion from the road surface becomes large, and the characteristics of the embedded type may be impaired. However, when the case 1 is buried so that its outer peripheral edge 2B matches the road surface, there is not much problem if the middle point (maximum protruding position) of the surface 2A of the case 1 is about 5 mm or less below the road surface. It is thought that there is no. Therefore, for example, in the case where the diameter (outer diameter) is 150 mm, if the radius of curvature of the surface 2A of the front cover 2 of the case 1 is 565 mm, the maximum height of the middle point of the surface 2A from the road surface is set. 5m
m.

The case 1 is buried in the road 11 such that the outer peripheral edge 2 B of the front cover portion substantially matches the road surface 10. Since the surface is spherical, dust adhering to the surface is likely to flow out by rainwater or the like, and does not remain on the surface.

Further, since the front cover is circular, the front cover is continuous with the road surface over the entire outer peripheral edge extending over 360 degrees, and the front cover is turned to provide an inclined surface at the edge of the front cover. As in the case of the shape, no step is formed on the surface, the peripheral portion, the corner portion, or the like. Therefore, there is no danger even if a vehicle or the like gets on the surface.

In the embodiment shown in FIG. 1, the light source 6 is inclined so that its optical axis is directed to the outer periphery of the case. Instead, as shown in FIG. May be arranged so as to be inclined inward.
According to this configuration, the elevation angle can be increased. Increasing the elevation angle is generally not preferred, but can be used when installed on a slope.

[0028]

As described above, according to the present invention, the surface of the front cover of the case housing the light source is made spherical, so that it can match the road surface without protruding from the road surface. Even when buried in a road, the loss of light from the light source can be reduced and the light can be radiated to the outside with a sufficiently small elevation angle. In addition, since the case is buried in the road so that the outer edge of the outer cover is circular and the outer edge of the outer cover coincides with the road surface, the outer edge of the outer cover is stepped by 360 degrees with respect to the road surface. Are not formed but continuous, so that even if the vehicle or the like gets on from any direction, no noise is generated, and no impact, rollover or other dangerous state is caused.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is a sectional view for explaining the operation of FIG. 1;

FIG. 5 is a cross-sectional view for explaining the operation of the conventional configuration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Front cover part 2A Surface of front cover part 2B Peripheral edge of front cover part 4 Solar electric field 5 Storage battery 6 Light source (light emitting diode) 8 Flat part 10 Road surface 11 Road

Continuation of the front page (56) References JP-A-59-179916 (JP, A) JP-A-53-142897 (JP, A) JP-A-5-89514 (JP, U) JP-A-49-77720 (JP , U) (58) Field surveyed (Int.Cl. ⁶ , DB name) E01F 9/06

Claims (1)

(57) [Claims] 1. A disk-shaped case provided with a light source including a solar cell, a storage battery and a light emitting diode therein has a circular front cover portion having a light-transmitting property, and the entire surface of the front cover portion has a spherical shape. In addition, the light source is disposed so that its optical axis is inclined with respect to the surface of the front cover portion, and further, on the back surface of the front cover portion, facing the light source, and substantially orthogonal to the optical axis of the light source. By providing a flat surface portion, light from the light source travels substantially straight toward the surface of the front cover portion through the flat surface portion, and the outer peripheral edge of the front cover portion substantially matches the road surface. A luminous sign device for roads, wherein the case is buried in a road to such an extent that the case is buried.