JP2014229478A - Lighting device for tunnel road - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device for a tunnel road realizing a pro-beam lighting (non-symmetrical lighting), letting a driver acknowledge a position of the lighting device in such a degree as one that the driver does not feel glare to assure an inductive characteristic for the driver within the tunnel without inclining a board having light emitting elements arranged therein and the entire lighting device toward the front side in a road forwarding direction or without installing another shading plate.SOLUTION: This invention relates to a lighting device 100 for a tunnel road installed within a one-way tunnel T to illuminate a road surface G in the tunnel T. This lighting device 100 comprises light emitting elements (110) for projecting light L against the road surface G and condenser lenses 120 installed at the side of the light emitting element (110) facing to the road surface characterized in that the center 120C of the condenser lens 120 is constituted to be displaced toward the front side of a road forwarding direction in respect to the center 110C of the light emitting element (110).

Description

  The present invention relates to an illumination device for a road in a tunnel which is disposed in a tunnel passing in one direction and illuminates a road surface in the tunnel.

2. Description of the Related Art Conventionally, an illumination device for a road in a tunnel that is disposed in a tunnel that passes in one direction and illuminates a road surface in the tunnel is known (see, for example, Patent Document 1).
As such a conventional tunnel road illumination device, for example, there is a tunnel road illumination device 700 as shown in FIGS. 9 (A) to 9 (C).
Here, FIG. 9A is a diagram showing an outline of a conventional tunnel road illumination device 700 according to the prior art, and FIG. 9B is a light distribution distribution diagram of the conventional tunnel road illumination device 700 according to the prior art. FIG. 9C is a plan illuminance distribution diagram of the road surface G when the conventional road illumination device 700 in the tunnel illuminates the road surface.

A conventional tunnel road lighting device 700 includes a light emitting diode 710 as shown in FIG.
The light emitting diode 710 was attached in a state where the direction of the light emitting diode 710 was tilted forward in the road traveling direction with respect to the lower side in the vertical direction.

In the conventional tunnel road lighting device 700, as shown in FIG. 9B, the peak of the distribution of luminous intensity (radiation intensity of the light L), which is the light distribution of the light emitting diode 710, is based on the light emitting diode 710. It was vertical.
Here, the vertical axis in FIG. 9B represents luminous intensity (cd), and the horizontal axis represents the road traveling direction with respect to the light emitting diode 710 when the vertical direction of the light emitting diode 710 is 0 °. The slope at D.
In this inclination, the − side is the rear side in the road traveling direction, and the + side is the front side in the road traveling direction.

  Then, as shown in FIG. 9C, when the tunnel road illumination device 700 illuminates the road surface G, the illuminance at a part of the road traveling direction front side from the tunnel road illumination device 700 becomes higher.

JP 2012-038532 A

  However, the above-described conventional tunnel road lighting device 700 has a structure in which the light emitting diode 710 is attached in a state where the direction of the light emitting diode 710 is tilted forward in the road traveling direction with respect to the lower side in the vertical direction. In front of the tunnel road lighting device 700, the driver of the automobile traveling in the tunnel T cannot visually recognize the light emission of the tunnel road lighting device 700 itself, and the driver's inductivity in the tunnel T cannot be secured. In addition, there is a problem in that the structure is complicated because parts for tilting the substrate on which the light emitting diode 710 is disposed and the entire lighting device to the front side in the road traveling direction are necessary.

  Therefore, the present invention solves the problems of the prior art as described above, that is, the object of the present invention is to tilt the substrate and the entire lighting device provided with the light emitting elements forward in the road traveling direction. Realizes pro-beam illumination (asymmetric illumination) without providing a separate light shielding plate, and ensures the driver's inductivity in the tunnel by allowing the driver to recognize the position of the lighting device to the extent that the driver does not feel dazzling It is to provide a lighting device for a road in a tunnel.

  The invention according to claim 1 is a lighting device for a road in a tunnel that is disposed in a tunnel that passes in one direction and illuminates a road surface in the tunnel, a light emitting element that emits light to the road surface, and the light emitting element And the center of the condensing lens is configured to deviate from the center of the light emitting element to the front side in the road traveling direction. It is a solution.

  In the invention according to claim 2, in addition to the configuration of the illumination device for a road in a tunnel according to claim 1, the light collecting lens includes a plurality of light diffusion members extending in a road width direction in the tunnel. By having the groove for use, the above-described problems are further solved.

  The invention according to claim 3 includes a light-transmitting sheet member disposed on the road surface side from the light emitting element in addition to the configuration of the lighting device for a road in a tunnel according to claim 1 or claim 2. The light-transmitting sheet member has a plurality of light diffusion grooves extending in the road width direction, thereby further solving the aforementioned problems.

  The invention according to claim 4 is characterized in that, in addition to the configuration of the illumination device for a road in a tunnel according to any one of claims 1 to 3, the light emitting element is a light emitting diode. It solves the problems that have been solved.

  According to a fifth aspect of the present invention, in addition to the configuration of the illumination device for a road in a tunnel according to any one of the first to fourth aspects, the light emitting element is a center in the road width direction in the tunnel. The center of the condensing lens is biased toward the other end side in the road width direction with respect to the center of the light emitting element. Thus, the above-described problem is further solved.

  The lighting device for a road in a tunnel according to the present invention can not only illuminate the road surface in the tunnel by being arranged in a tunnel that passes in one direction, but also has the following specific effects. .

According to the lighting device for a road in a tunnel according to the first aspect of the present invention, the light-emitting element that emits light to the road surface and the condensing lens disposed on the road surface side of the light-emitting element are provided. Since the center of the lens is deviated forward of the road traveling direction with respect to the center of the light emitting element, the mountain of the distribution of luminous intensity (light emission intensity) that is the light distribution with respect to the light emitting element is the road. The amount of light emitted toward the front of the road in the direction of travel is small and the amount of light radiated to the rear of the road is small. This ensures pro-beam illumination (asymmetric illumination) while maintaining the illuminance of the road surface in the tunnel, and the driver is dazzled. The driver can recognize the position of the lighting device as much as possible, and the driver's inductivity in the tunnel can be secured.
Furthermore, since the amount of light radiated to the rear side in the road traveling direction is reduced by simply changing the position of the condensing lens with respect to the light emitting element, the substrate on which the light emitting element is disposed and the entire lighting device are tilted forward in the road traveling direction. In addition, it is possible to achieve both maintenance of road surface illumination and ensuring driver inductivity without providing a separate light shielding plate.

In addition, the curve behind the road traveling direction from the peak of the luminous intensity (light intensity) distribution is gentler and the curve level is lower than the unbiased structure of the prior art. Since the illuminance near the installation position of the lighting device in the direction of travel of the road that is most likely to have the highest illuminance is lower than that of the conventional structure without deviation, the unevenness of the light and darkness of the road surface in the direction of travel of the road is reduced. It can be reduced to increase the illuminance uniformity.
Here, “illuminance uniformity” refers to a value representing the degree of uniformity of the illuminance distribution, and specifically refers to a value obtained by dividing the minimum illuminance by the maximum illuminance.
For reference, there are two types of “luminance uniformity”: total uniformity (Uo) that affects the appearance of obstacles and lane uniformity (Ul) that affects the driving comfort of the driver. "Uniformity" also greatly affects the safety of driving.

  According to the lighting device for a road in a tunnel according to the second aspect of the present invention, in addition to the effect produced by the invention according to the first aspect, the condensing lens includes a plurality of lights extending in the width direction of the road in the tunnel. Because of the diffusion grooves, the light is diffused back and forth on the uneven slope of the surface of the condenser lens, so the road travels with other road lighting devices next to the road travel direction. The unevenness of the light and darkness of the road surface in the direction can be reduced and the illuminance uniformity can be increased.

  According to the lighting device for a road in a tunnel of the invention according to claim 3, in addition to the effect produced by the invention according to claim 1 or claim 2, the light transmissive sheet member disposed on the road surface side from the light emitting element. The light-transmitting sheet member has a plurality of light diffusion grooves extending in the width direction of the road, so that light is diffused more or less on the uneven surface of the surface of the sheet member. Therefore, it is possible to further reduce the unevenness of the light and darkness of the road surface in the road traveling direction with another road illumination device adjacent to the road traveling direction, and to further increase the illuminance uniformity.

  According to the lighting device for a road in a tunnel of the invention according to claim 4, in addition to the effect exerted by the invention according to any one of claims 1 to 3, the light emitting element is a light emitting diode. Compared with the case where the light emitting element is a light bulb such as a mercury lamp or a halogen lamp, the size of the light emitting element is reduced and the service life is extended even if the brightness is comparable. Can be reduced.

  According to the lighting device for a road in a tunnel according to the fifth aspect of the present invention, in addition to the effect produced by the invention according to any one of the first to fourth aspects, the light emitting element is provided in the direction of the width of the road in the tunnel. By being arranged above the road surface at one end in the road width direction with respect to the center, the center of the condensing lens is also biased toward the other end in the road width direction with respect to the center of the light emitting element. Compared to a structure that is not biased toward the other end in the road width direction, the peak of the distribution of light intensity (radiation intensity), which is the light distribution based on the light emitting element, is biased toward the other end in the road width direction. Since the illuminance on the road surface on the other end side in the direction becomes high and the illuminance on the road surface on the one end side in the road width direction becomes low, the unevenness of light and darkness on the road surface in the road width direction can be reduced and the illuminance uniformity can be increased.

In other words, the position where the light with the strong peak of the light intensity distribution shines is near the inside of the other end in the road width direction, and the illuminance near the inside of the other end in the road width direction where the distance is farthest from the light emitting position and the illuminance tends to be the lowest is Since the height is higher than a structure that is not biased toward the other end in the road width direction, unevenness in the brightness of the road surface in the road width direction can be reduced, and the illuminance uniformity can be increased.
In other words, it is possible to increase the visibility of obstacles on the road surface by the driver and enhance safety.

Furthermore, the slope of the curve on the other side in the road width direction from the peak of the light intensity distribution is steep compared to the structure that is not biased to the other side in the road width direction, and the light that protrudes outside the other end in the road width direction Since the amount is reduced, it is possible to reduce the waste of the illumination range and increase the illumination efficiency.
In addition, as an adverse effect of light that protrudes outside the other end in the road width direction, for example, the light that protrudes outside the other end in the road width direction hits the inner wall surface of the tunnel to prevent irregular reflection of light from the inner wall surface of the tunnel. Driving safety can be increased.

  On the other hand, the slope of the curve at one end in the road width direction from the peak of the light intensity distribution is gentler and the level of the curve is lower than the structure that is not biased toward the other end in the road width direction, and the distance from the light emitting position is the longest. Since the illuminance at one end in the road width direction, where the illuminance tends to be the highest near, is lower than the structure that is not biased toward the other end in the road width direction, the unevenness of the light and darkness of the road surface in the road width direction is reduced. The illuminance uniformity can be increased.

The perspective view which shows the tunnel which installed the illuminating device for tunnel roads which is 1st Example of this invention. Sectional drawing which looked in the tunnel of FIG. 1 toward the front side of the advancing direction. The front view and side view which show the illuminating device for roads which is 1st Example of this invention. The light distribution distribution map and road surface illuminance distribution map of the road illumination device according to the first embodiment of the present invention. Plane illumination distribution map of the road surface which shows and compares the 1st example of the present invention and a comparative example. The illuminating device for roads in a tunnel which is 2nd Example of this invention, its light distribution, and road surface illuminance distribution figure. The figure which shows the illuminating device for tunnel roads which is 3rd Example of this invention. The illuminating device for roads in a tunnel which is 4th Example of this invention, its light distribution, and road surface illuminance distribution figure. The figure which shows the illuminating device for tunnel roads of a prior art, a light distribution distribution map, and the plane illuminance distribution map of a road surface.

  The present invention relates to a lighting device for a road in a tunnel that is disposed in a tunnel that passes in one direction and illuminates a road surface in the tunnel, a light emitting element that emits light to the road surface, and a light emitting element disposed on the road surface side of the light emitting element. The center of the condenser lens is configured to be deviated toward the front side of the road traveling direction with respect to the center of the light emitting element, thereby maintaining the illuminance of the road surface in the tunnel, Pro beam illumination (asymmetric illumination) is realized, and the driver recognizes the position of the lighting device to the extent that the driver does not feel dazzling, ensuring the driver's inductivity in the tunnel, and arranging the light emitting element If it is possible to maintain the road surface illumination and ensure the driver's inductivity without inclining the entire board or lighting device forward in the direction of road travel or providing a separate light shielding plate, the actual Aspects, may be any one.

Further, the light emitting element may be anything as long as it emits light.
Further, the condensing lens may be a sheet-type Fresnel lens having a fine groove instead of a dome-shaped convex lens as long as it has a function of collecting light.
Further, the installation posture of the lighting device for a road in the tunnel may be inclined with respect to the road surface or may be parallel.

Hereinafter, a tunnel road illumination device 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5B.
Here, FIG. 1 is a perspective view showing a tunnel T in which a lighting device 100 for a road in a tunnel according to a first embodiment of the present invention is installed, and FIG. 2 is a front view in the traveling direction in the tunnel T of FIG. FIG. 3A is a diagram showing the tunnel road lighting device 100 viewed from the reference numeral 3A shown in FIG. 2, and FIG. 3B is a diagram showing FIG. 3A. FIG. 4A is a diagram showing a light distribution distribution of the tunnel road illumination device 100 according to the first embodiment of the present invention. FIG. 4B is a road surface illuminance distribution diagram when the road illumination device 100 in the tunnel according to the first embodiment of the present invention illuminates the road surface G, and FIG. The amount of plane illuminance on the road surface G when the road illumination device 100 in the tunnel according to the embodiment illuminates the road surface G. A diagram, FIG. 5 (B) is a plan illuminance distribution diagram of the road surface G when the prior art road lighting device 700 as a comparative target is illuminated road surface G.

The tunnel road illumination device 100 according to the first embodiment of the present invention is a tunnel that travels in one direction in order to illuminate the light L on the road in the tunnel T, as shown in FIGS. It is installed on the inner wall surface TW of the tunnel in T.
As shown in FIG. 1, a plurality of in-tunnel road lighting devices 100 are arranged in the road traveling direction D at positions above the road surface G on both sides of the road width direction with respect to the center C in the road width direction.

One of the tunnel lighting devices 100 in the tunnel will be described.
As shown in FIG. 2, one tunnel road illumination device 100 is configured to illuminate the road surface G by being disposed above the road surface G on the road width direction one end E1 side with respect to the center C in the road width direction. Has been.
In other words, one in-tunnel road lighting device 100 is configured to illuminate the road surface G from one end E1 side in the road width direction toward the other end side with respect to the center C in the road width direction.
Hereinafter, with respect to the center C in the road width direction, the side on which one in-tunnel road lighting device 100 is disposed will be described as one end E1 side in the road width direction.

3A and 3B, the light emitting diode 110, which is an example of a light emitting element that emits light L to the road surface G, and the road surface G side of the light emitting diode 110 are disposed. And a condensing lens 120.
Furthermore, the center 120 </ b> C of the condenser lens 120 is configured to be deviated forward of the road traveling direction with respect to the center 110 </ b> C of the light emitting diode 110.

As a result, as shown in FIG. 4A, the luminous intensity (radiation intensity of the light L), which is a light distribution based on the light emitting diode 110, as compared with the conventional structure without bias (curved line). The amount of the light L emitted toward the rear side in the road traveling direction is small because the mountain of the distribution is biased to the front side in the road traveling direction.
Here, the vertical axis in FIG. 4A represents the luminous intensity (cd), and the horizontal axis represents the road traveling direction with respect to the light emitting diode 110 when the vertical direction of the light emitting diode 110 is 0 °. The slope at D.
In this inclination, the − side is the rear side in the road traveling direction, and the + side is the front side in the road traveling direction.

Furthermore, only by changing the position of the condensing lens 120 with respect to the light emitting diode 110, the amount of light L radiated to the rear side in the road traveling direction becomes small.
In addition, the curve behind the road traveling direction from the peak of the distribution of luminous intensity (radiation intensity of light L) is gentler and the level of the curve is lower than that of the conventional structure (curve shown by a broken line) that is not biased. Become.

Then, as shown in FIGS. 4B and 5A, the illuminance in the vicinity of the illuminating device installation position in the road traveling direction D that is closest to the light emission position and tends to have the highest illuminance is It is lower than the structure that is not biased (the curve shown by the broken line in FIG. 4B and FIG. 5B).
Here, the vertical axis in FIG. 4B represents the road surface illuminance (Lx), and the horizontal axis represents the position on the road surface G in the road traveling direction D.
5A corresponds to the solid line in FIG. 4B, and FIG. 5B corresponds to the chain line in FIG. 4B.

  The tunnel lighting device 100 in the tunnel according to the first embodiment of the present invention thus obtained includes a light emitting diode 110 that is an example of a light emitting element that emits light L to the road surface G, and the light emitting diode 110. A condensing lens 120 disposed on the road surface G side, and the center 120C of the condensing lens 120 is configured to be deviated forward of the road traveling direction with respect to the center 110C of the light emitting diode 110. While maintaining the illuminance of the road surface G in the tunnel T, the pro-beam illumination (asymmetric illumination) is realized and the driver recognizes the position of the illumination device 100 for the road in the tunnel to the extent that the driver does not feel dazzling. The driver's inductivity within T can be ensured, and the board with the light emitting element and the entire lighting device tilted forward in the road traveling direction or a light shielding plate is provided separately. With Ku compatible and ensure inducible maintenance and driver illuminance of the road surface G, it can increase the illuminance uniformity ratio by reducing variations in brightness of the road surface G in the road traveling direction D.

  Furthermore, since the light emitting element is the light emitting diode 110, the size of the lighting device 100 for a road in a tunnel can be reduced and the burden of maintenance can be reduced.

Next, a tunnel road lighting device 200 according to a second embodiment of the present invention will be described with reference to FIGS. 6 (A) to 6 (D).
Here, FIG. 6 (A) is a figure which shows the principal part of the illuminating device 200 for tunnel roads of 2nd Example of this invention, FIG.6 (B) is the code | symbol 6B shown in FIG. 6 (A). FIG. 6C is a cross-sectional view as seen from −6B, FIG. 6C is a light distribution diagram of the tunnel road lighting device 200 according to the second embodiment of the present invention, and FIG. It is a road surface illuminance distribution map at the time of the road surface illumination device 200 which is 2nd Example of this illuminating the road surface G. FIG.

  The in-tunnel road lighting device 200 according to the second embodiment has a plurality of light diffusion grooves 221 formed on the surface of the condenser lens 120 of the in-tunnel road lighting device 100 according to the first embodiment. Since the elements are the same as those in the tunnel road lighting device 100 of the first embodiment, detailed description of the common matters is omitted, and only the reference numerals of the 200 series in which the last two digits are common are attached.

As shown in FIGS. 6A and 6B, the condensing lens 220 of the tunnel road illumination device 200 according to the second embodiment of the present invention extends in the road width direction W in the tunnel T. And a plurality of light diffusion grooves 221.
Thereby, the light L is diffused back and forth on the road traveling direction on the uneven slope of the surface of the condenser lens 220.

Specifically, as shown in FIG. 6C, the road travels perpendicular to the extending direction of the light diffusion groove 221 as compared with the structure without the light diffusion groove 221 (curve indicated by a broken line). The light distribution is distributed on both sides of the direction, the peak is lowered, and the peak of the distribution peak is raised.
Here, the vertical axis in FIG. 6C represents the luminous intensity (cd), and the horizontal axis represents the road traveling direction with respect to the light emitting diode 210 when the vertical direction of the light emitting diode 210 is 0 °. The slope at D.
In this inclination, the − side is the rear side in the road traveling direction, and the + side is the front side in the road traveling direction.

Then, as shown in FIG. 6 (D), the road surface G on the front side in the road traveling direction from the position where the lighting device 200 for the road in the tunnel is located in the road traveling direction D, which is close to the light emission position and tends to have high illuminance. The illuminance is lower than that of a structure that does not have the light diffusion groove 221 (curve indicated by a broken line).
Further, as shown in FIG. 6D, the road traveling direction D, which is far from the light emission position and the illuminance tends to be low, and the illuminance of the road surface G on the front side and the rear side has a light diffusion groove 221. Compared to a structure without a curve (curved line).
In the second embodiment of the present invention, the light diffusion groove 221 is formed on the surface on the road surface G side of the condenser lens 220, but may be formed on the back surface on the light emitting diode 210 side.

  In the tunnel road illumination device 200 according to the second embodiment of the present invention thus obtained, the condenser lens 220 has a plurality of light diffusion grooves 221 extending in the road width direction W. By reducing the unevenness of the light and darkness of the road surface G in the road traveling direction D with another lighting device 200 for roads in the tunnel adjacent to the road traveling direction, the illuminance uniformity can be increased. The effect is enormous.

Next, a tunnel road illumination device 300 according to a third embodiment of the present invention will be described with reference to FIGS. 7 (A) to 7 (C).
Here, FIG. 7 (A) is a diagram showing a tunnel road illumination device 300 according to a third embodiment of the present invention corresponding to FIG. 3 (B), and FIG. ) Shown in FIG. 7B, and FIG. 7C is a cross-sectional view taken along the line 7C-7C shown in FIG. 7B.

  In the tunnel road illumination device 300 according to the third embodiment, a light transmissive sheet member 330 is disposed on the road surface G side of the condenser lens 120 of the tunnel road illumination device 100 according to the first embodiment. Since many elements are the same as those in the tunnel road lighting device 100 of the first embodiment, detailed description of common items is omitted, and only the reference numbers in the 300 series having the last two digits are attached.

As shown in FIGS. 7A to 7C, the tunnel road illumination device 300 according to the third embodiment of the present invention is a light-transmissive sheet member disposed on the road surface G side from the light emitting diode 310. 330 is provided.
Further, the light transmissive sheet member 330 has a plurality of light diffusion grooves 331 extending in the road width direction W.

As a result, the light L is diffused back and forth in the road traveling direction on the uneven slope of the surface of the light transmissive sheet member 330, as in the operation and effect of the in-tunnel road lighting device 200 of the second embodiment.
In addition, when used in combination with the condensing lens 220 of the second embodiment, the light L is diffused forward and backward in the road traveling direction.
In the third embodiment of the present invention, the light diffusion groove 331 is formed on the surface on the road surface G side of the light transmissive sheet member 330, but may be formed on the back surface on the light emitting diode 310 side.
Further, although the light transmissive sheet member 330 is provided on the road surface G side with respect to the condensing lens 320, the light transmissive sheet member 330 may be provided between the condensing lens 320 and the light emitting diode 310.

  The tunnel road illumination device 300 according to the third embodiment of the present invention thus obtained includes a light transmissive sheet member 330 disposed on the road surface G side from the light emitting diode 310, and this light transmissive property is provided. Since the sheet member 330 has a plurality of light diffusion grooves 331 extending in the road width direction W, the road traveling direction between the lighting device 300 for the other roads in the tunnel adjacent to the road traveling direction. The effect is enormous, for example, the unevenness of light and darkness of the road surface G at D can be further reduced and the illuminance uniformity can be further increased.

Next, an in-tunnel road lighting device 400 according to a fourth embodiment of the present invention will be described with reference to FIGS. 8 (A) to 8 (C).
Here, FIG. 8 (A) is a view showing a tunnel road illumination device 400 according to a fourth embodiment of the present invention corresponding to FIG. 3 (A), and FIG. 8 (B) is a diagram of the present invention. FIG. 8D is a light distribution distribution diagram of the tunnel road illumination device 400 according to the fourth embodiment. FIG. 8D illustrates a case where the tunnel road illumination device 400 according to the fourth embodiment of the present invention illuminates the road surface G. It is a road surface illuminance distribution map.

  In the tunnel road illumination device 400 according to the fourth embodiment, the center 120C of the condenser lens 120 of the tunnel road illumination device 100 according to the first embodiment is connected to the center 110C of the light emitting diode 110 in the road width direction other end E2. Since it is also biased to the side and is common to the lighting device 100 for a tunnel road in the first embodiment with respect to many elements, detailed description of common items is omitted, and the 400 series in which the last two digits are common Only the sign of

In the tunnel road illumination device 400 according to the fourth embodiment of the present invention, the light emitting diode 410, which is an example of a light emitting element, has a road surface G on one end E1 side in the road width direction with reference to the center C in the road width direction in the tunnel T. It is arranged further upward.
Further, as shown in FIG. 8A, the center 420C of the condenser lens 420 is configured to be biased toward the other end E2 side in the road width direction with respect to the center 410C of the light emitting diode 410.

As a result, as shown in FIG. 8B, the luminous intensity (light intensity) is a light distribution based on the light emitting diodes 410 as compared to a structure (curved line indicated by a broken line) that is not biased toward the other end E2 side in the road width direction. The peak of the distribution of (L radiation intensity) is biased toward the other end E2 side in the road width direction.
In other words, the target position to which the light L having a strong peak in the luminous intensity distribution is emitted is near the inside of the other end E2 in the road width direction.
Here, the vertical axis in FIG. 8B represents luminous intensity (cd), and the horizontal axis represents the road width direction with respect to the light emitting diode 410 when the vertical direction of the light emitting diode 410 is 0 °. The slope at W.
In this inclination, the minus side is the road width direction one end E1 side, and the plus side is the road width direction other end E2 side.

As shown in FIG. 8C, the illuminance of the road surface G on the other end E2 side in the road width direction is higher than the structure (curved line indicated by the broken line) that is not biased toward the other end E2 side in the road width direction. The illuminance of the road surface G on the one end E1 side in the road width direction becomes low.
In other words, the illuminance in the vicinity of the inner side of the other end E2 in the road width direction where the distance from the light emission position is the longest and the illuminance tends to be the lowest is not biased toward the other end E2 side in the road width direction (FIG. 8C). It becomes higher than the curve (shown by a broken line).
Here, the vertical axis in FIG. 8C represents road surface illuminance (Lx), and the horizontal axis represents a position on the road surface G in the road width direction W.

Furthermore, as shown in FIG. 8 (B), the slope of the curve on the other end E2 side in the road width direction from the peak of the light intensity distribution (the + side of the horizontal axis in FIG. 8 (B)) is on the other end E2 side in the road width direction. Compared to an unbiased structure (curved line indicated by a broken line), it becomes steep.
Then, as shown in FIG. 8C, the amount of light L that protrudes outward from the other end E2 in the road width direction as compared with the structure that is not biased toward the other end E2 in the road width direction (curved line). Less.
In other words, the amount of light L falling on the tunnel inner wall surface TW is reduced compared to a structure (curved line indicated by a broken line) that is not biased toward the other end E2 side in the road width direction.

Further, as shown in FIG. 8B, the slope of the curve on one end E1 side in the road width direction (the negative side of the horizontal axis in FIG. 8B) from the peak of the luminous intensity distribution is biased toward the other end E2 side in the road width direction. Compared to a structure that does not (curve shown by a broken line), the level of the curve becomes lower.
Then, as shown in FIG. 8C, the illuminance on the road width direction one end E1 side where the illuminance is closest to the light emission position and the illuminance is the highest is not biased toward the other end E2 side in the road width direction ( Lower than the curve indicated by the broken line).

  In the tunnel road illumination device 400 according to the fourth embodiment of the present invention thus obtained, the light-emitting diode 410 as an example of the light-emitting element has a road with the center C in the road width direction in the tunnel T as a reference. It is disposed above the road surface G on the width direction one end E1 side, and the center 420C of the condensing lens 420 is configured to be biased toward the other end E2 side in the road width direction with respect to the center 410C of the light emitting diode 410. Thus, compared with the structure not biased toward the other end E2 side in the road width direction, the unevenness of the light and darkness of the road surface G in the road width direction W is reduced and the illuminance uniformity is increased, so that the obstacle of the road surface G by the driver The effect can be enormous, such as improving the visibility and improving safety, and reducing the waste of the illumination range and increasing the illumination efficiency.

100, 200, 300, 400 ... lighting devices for roads in tunnels 110, 210, 310, 410 ... light emitting diode (light emitting element)
110C, 410C ... Light emitting diode centers 120, 220, 320, 420 ... Condensing lens 120C, 420C ... Condensing lens center 221 ... Light diffusion groove
330 ... Light transmissive sheet member
331 ... Light diffusion groove 700 ... Prior art lighting device for road in tunnel 710 ... Light emitting diode C ... Road width direction center D ... Road traveling direction E1 ... One end of road width direction E2 ・ ・ ・ Road width direction other end G ・ ・ ・ Road surface L ・ ・ ・ Light T ・ ・ ・ Tunnel TW ・ ・ ・ Tunnel inner wall surface W ・ ・ ・ Road width direction

Claims (5)

In a lighting device for a road in a tunnel that is arranged in a tunnel that passes in one direction and illuminates the road surface in the tunnel,
A light emitting element that emits light to the road surface;
A condensing lens disposed on the road surface side of the light emitting element,
An illumination device for a road in a tunnel, characterized in that the center of the condensing lens is configured to deviate toward the front side in the road traveling direction with respect to the center of the light emitting element.   2. The tunnel road illumination device according to claim 1, wherein the condenser lens has a plurality of light diffusion grooves extending in a road width direction in the tunnel.   A light transmissive sheet member disposed on the road surface side from the light emitting element is provided, and the light transmissive sheet member has a plurality of light diffusion grooves extending in the road width direction. The lighting device for a road in a tunnel according to claim 1 or 2.   The illumination device for a road in a tunnel according to any one of claims 1 to 3, wherein the light emitting element is a light emitting diode. The light emitting element is disposed above the road surface on one end side in the road width direction with respect to the center in the road width direction in the tunnel,
The center of the condensing lens is configured to be deviated also on the other end side in the road width direction with respect to the center of the light emitting element. Lighting equipment for roads in tunnels.

Images