JP7720544B2 - Illumination lens, illumination device, and illumination system - Google Patents

Description

The present invention relates to an illumination lens, an illumination device and an illumination system.

Traditionally, mercury lamps and high-pressure sodium lamps have been used in lighting devices installed on roads. However, in recent years, lighting devices that use light-emitting elements such as LEDs (Light Emitting Diodes) as light sources have been put into practical use in order to achieve longer life, higher brightness, and lower power consumption.

Patent Document 1 also discloses a light distribution control lens used in a lamp (lighting device). By using the light distribution control lens of Patent Document 1 in a lighting device that uses an LED as a light source, the illumination range of the lighting device can be expanded. This allows the lighting devices to be installed at wider intervals, thereby reducing the installation costs of the lighting devices.

Patent No. 6604593

An illumination lens according to one embodiment of the present invention is an illumination lens used in a lighting device installed on a road. The illumination lens is positioned so that its front direction is perpendicular to the parallel direction along the road's traveling direction, and is equipped with an incident surface that receives light emitted from a light source, an exit surface that emits light that has entered the incident surface, a first region formed on at least one of the incident surface and the exit surface so as to irradiate a first light toward the road's traveling direction, and a second region formed on at least one of the incident surface and the exit surface so as to irradiate light that is more diffused than the first light toward the side opposite the road's traveling direction.

FIG. 2 is a front view of the illumination lens according to the embodiment. FIG. 2 is a side view of the illumination lens according to the embodiment. FIG. 1 is a perspective view of an illumination lens according to an embodiment of the present invention. FIG. 3 is a side view showing light rays emitted from the illumination lens according to the embodiment. FIG. 2 is a cross-sectional view showing an installation state of the lighting device according to the embodiment. FIG. 1 is a plan view showing an installation state of a lighting device according to an embodiment of the present invention. FIG. 3 is a diagram showing the illuminance distribution of the lighting device according to the embodiment. FIG. 3 is a diagram showing the illuminance distribution of the lighting device according to the embodiment. FIG. 3 is a diagram showing the illuminance distribution of the lighting device according to the embodiment. FIG. 3 is a diagram showing the illuminance distribution of the lighting device according to the embodiment. FIG. 3 is a diagram showing the illuminance distribution of the lighting device according to the embodiment. FIG. 2 is a plan view showing the arrangement of lighting devices in the lighting system according to the embodiment. FIG. 10 is a front view showing another example of the illumination lens according to the present embodiment. FIG. 10 is a perspective view showing another example of the illumination lens according to the embodiment. 15 is a cross-sectional view of an illumination device using the illumination lens of FIG. 14. FIG. 10 is a plan view showing the illuminance distribution of another example of the illumination lens according to the embodiment. FIG. 10 is a plan view showing the illuminance distribution of another example of the illumination lens according to the embodiment. FIG. 10 is a plan view showing the illuminance distribution of another example of the illumination lens according to the embodiment. FIG. 3 is a side view showing light rays emitted from the illumination lens according to the embodiment.

In order to increase the spacing between lighting devices, it is necessary to increase the light distribution of the lighting devices and strengthen the light they emit. In this case, if the light distribution of the lighting devices is made too wide or the light emitted by the lighting devices is made too strong, the brightness of the road surface will increase. This can result in glare being caused by strong light entering the field of vision of drivers of vehicles traveling on the road.

Therefore, an embodiment of the present invention aims to reduce glare while expanding the illumination range of a lighting device.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the present invention, its applications, or its uses.

(Configuration of lighting lens)
Fig. 1 shows a front view of the lighting lens according to this embodiment, Fig. 2 shows a side view of the lighting lens according to this embodiment, and Fig. 3 shows a perspective view of the lighting lens according to this embodiment. Fig. 4 is a side view showing light rays emitted from the lighting lens according to this embodiment. In the following description, the X direction indicates a parallel direction along the direction of travel of a road 21 (described later), the Y direction indicates the front direction of the lighting lens 1, and the Z direction indicates a vertical direction perpendicular to the X and Y directions. In Fig. 4, the light rays emitted from the lighting lens 1 are shown by dashed lines.

As shown in Figures 1 to 4, the lighting lens 1 is made of a transparent material that refracts light, and diffuses light emitted from a light source 11 having a light-emitting element such as an LED (Light Emitting Diode) in the X direction.

Specifically, the lighting lens 1 has an incident surface 2 that receives light emitted from the light source 11, and an exit surface 3 that emits light that has entered the incident surface 2. The incident surface 2 is formed concavely so as to cover the light source 11. The exit surface 3 is formed convexly at a position opposite the incident surface 2. For convenience, in Figures 1 to 4, the light source 11 is positioned so that it coincides with the center point of the lighting lens 1 when viewed from the Y direction, but this is not limited to this.

In addition, regions 2a to 2d are formed on the incident surface 2. In FIG. 1, if the axis that passes through the center point of the illumination lens 1 and extends in the Z direction is axis Z1 and the axis that extends in the X direction is axis X1, region 2a is formed to the left of axis Z1 and above axis X1, region 2b is formed to the right of axis Z1 and above axis X1, region 2c is formed to the left of axis Z1 and below axis X1, and region 2d is formed to the right of axis Z1 and below axis X1. In other words, regions 2a and 2b are separated by axis Z1, and regions 2c and 2d are separated by axis Z1. Regions 2a and 2c are separated by axis X1, and regions 2b and 2d are separated by axis X1.

As shown in Figures 1 to 3, the entrance surface 2 is formed to have a curved surface that is asymmetric with respect to the axis Z1, and is also formed to have a curved surface that is asymmetric with respect to the axis X1. That is, the curved surfaces of regions 2a, 2c and regions 2b, 2d are asymmetric, and the curved surfaces of regions 2a, 2b and regions 2c, 2d are asymmetric.

Also, regions 3a to 3d are formed on the exit surface 3. In Figure 1, region 3a is formed to the left of axis Z1 and above axis X1, region 3b is formed to the right of axis Z1 and above axis X1, region 3c is formed to the left of axis Z1 and below axis X1, and region 3d is formed to the right of axis Z1 and below axis X1. In other words, regions 3a and 3b are separated by axis Z1, and regions 3c and 3d are separated by axis Z1. Regions 3a and 3c are separated by axis X1, and regions 3b and 3d are separated by axis X1.

As shown in Figures 1 to 3, the exit surface 3 is formed to have a curved surface that is asymmetric with respect to the axis Z1, and is also formed to have a curved surface that is asymmetric with respect to the axis X1. That is, the curved surfaces of regions 3a, 3c and regions 3b, 3d are asymmetric, and the curved surfaces of regions 3a, 3b and regions 3c, 3d are asymmetric.

In Figure 1, for convenience, the intersection of axes Z1 and X1 is taken as the center point of the illumination lens 1, but this intersection can be set arbitrarily.

As shown in Figures 4 and 17, the illumination lens 1 has an asymmetric light distribution in regions 3a and 3b (2a and 2b) with respect to axis Y1, which passes through the center point of the illumination lens 1 and extends along the Y axis. As shown in Figure 17, the incident surface 2 includes regions 2a and 2b. The exit surface 3 includes regions 3a and 3b. First light 15 enters region 2a and exits from region 3a. Second light 16 enters region 2b and exits from region 3b. The first light 15 is, for example, parallel light. Specifically, the first light 15 includes a light beam 15a and a light beam 15b that is parallel to light beam 15a. The second light 16 is more diffused than the first light 15. Specifically, the second light 16 includes a light beam 16a and a light beam 16b that is non-parallel to light beam 16a. In this embodiment, the second light 16 is emitted from the region 3 b, then converges at the point 16 c, and then diffuses. However, the present disclosure is not limited to this, and the second light 16 may be diffused without being converged. In this embodiment, the first light 15 is parallel light, but it does not necessarily have to be strictly parallel, as long as the second light 16 is more diffused than the first light 15.

Although not shown in the figures, the illumination lens 1 also has asymmetric light distribution in regions 3c and 3d (regions 2c and 2d). Light emitted from region 3c of the illumination lens 1 is more diffused in the X direction than light emitted from region 3d. In other words, the third light that enters region 2d and exits region 3d is parallel light. The fourth light that enters region 2c and exits region 3c is light that is slightly diffused from the parallel light. In this embodiment, the third light is parallel light, but it does not necessarily have to be strictly parallel; it is sufficient that the fourth light is more diffused than the third light.

(Light distribution of lighting equipment)
Fig. 5 is a cross-sectional view showing an installation state of the lighting device according to this embodiment. The lighting device 10 is installed in a tunnel 22 and irradiates light onto the road surface 21. In Fig. 5, the left-right direction of the drawing corresponds to the width direction of the road 21.

The lighting device 10 comprises a lighting lens 1 and a light source 11. The lighting device 10 is installed on the wall surface of the tunnel 22 so that its height from the road 21 is h and its installation angle relative to the road 21 is θ1.

Figure 6 is a plan view showing the installation state of the lighting device of this embodiment. Note that the tunnel 22 is omitted from the illustration in Figure 6.

As shown in Figure 6, road 21 is formed with lane 23 and lane 25, which is the oncoming lane of lane 23, separated by a center line 24. In the following description, the traveling direction of vehicle 26 traveling in lane 23 is referred to as traveling direction S1 (first traveling direction), and the traveling direction of vehicle 27 traveling in lane 25 is referred to as traveling direction S2 (second traveling direction). These traveling directions S1 and S2 coincide with the X direction.

Figures 7 to 11 are diagrams showing the illuminance distribution of the lighting device according to this embodiment. Specifically, Figure 7 shows the illuminance distribution of lighting device 10, Figure 8 shows only the illuminance distribution of light emitted from region 3a of exit surface 3, Figure 9 shows only the illuminance distribution of light emitted from region 3b of exit surface 3, Figure 10 shows only the illuminance distribution of light emitted from region 3c of exit surface 3, and Figure 11 shows only the illuminance distribution of light emitted from region 3d of exit surface 3. Note that in Figures 7 to 11, areas with the same illuminance are shown connected by curved lines.

Figures 7 to 11 show, in a plan view, the illuminance distribution of the lighting device 10 in an area of ±30 m in the direction of travel and ±3 m in the width direction of the road 21, with the intersection O between the front direction of the lighting lens 1 and the center line 24 as the center. The lighting device 10 is installed at a position of ±0 m in the direction of travel, -1.8 m in the width direction, and at a height h = 5 m.

As shown in Figure 7, the illuminance of the road surface of road 21 gradually decreases with increasing distance from intersection O. Here, in lane 23, the illuminance distribution is asymmetric between road surface 23a on the left side of the drawing and road surface 23b on the right side of the drawing with respect to the center of the drawing (a line passing through intersection O and parallel to the width direction). In lane 25, the illuminance distribution is asymmetric between road surface 25a on the left side of the drawing and road surface 25b on the right side of the drawing with respect to the center of the drawing.

Specifically, in lane 23, the illuminance distribution of lighting device 10 is significantly spread to the right side of the drawing (road surface 23b). This broadens the illumination range of lighting device 10 in the direction of travel S1, improving visibility for the driver of vehicle 26 traveling in lane 23. Furthermore, in lane 23, the illuminance distribution of lighting device 10 does not significantly spread to the left side of the drawing (road surface 23a), and the intervals between the curves representing the illuminance distribution are narrow. This narrows the illumination range of lighting device 10 on the opposite side of direction of travel S1, and also reduces the illuminance, thereby reducing glare for the driver of vehicle 26. Although detailed explanations are omitted, a similar effect can be achieved in lane 25.

(About the lighting system)
FIG. 12 is a plan view showing the arrangement of lighting devices in the lighting system according to this embodiment.

In FIG. 12, multiple lighting devices 10 are arranged in a staggered arrangement along the road 21 in the direction of travel of the road 21 within a tunnel (not shown). Each of the multiple lighting devices 10 emits light toward the road 21. The staggered arrangement means that the multiple lighting devices 10 are arranged alternately at equal intervals between the current lane and the opposite lane. Specifically, the multiple lighting devices 10 include multiple first lighting devices 10 (10a) arranged in the lane 23 and multiple second lighting devices 10 (10b) arranged in the lane 25. The multiple first lighting devices 10 (10a) are arranged at a first interval along the lane 23. The multiple second lighting devices 10 (10b) are arranged at a second interval along the lane 25. The second interval may be the same as the first interval. The multiple first lighting devices 10 (10a) are arranged with an offset in the direction of travel relative to the multiple second lighting devices 10 (10b). The offset may be half the length of the first interval or may be some other length. In Fig. 12, an illumination range 28 indicates the illumination range of the corresponding lighting device 10 on the road 21. By arranging the lighting devices 10 in a staggered arrangement along the road 21 in this manner, the entire surface of the road 21 can be illuminated.

As mentioned above, lighting device 10b irradiates less light onto area 29 in the upper left corner of the drawing. However, lighting device 10a has a wide illuminance distribution on the right side of the drawing, so the illuminance of area 29 can be maintained at a certain level or higher. This prevents a decrease in the road surface illuminance of road 21.

With the above configuration, the lighting lens according to this embodiment is a lighting lens 1 used in a lighting device 10 installed on a road 21, and the lighting lens 1 is positioned so that its front direction is perpendicular to the X direction. The lighting lens 1 has an incident surface 2 that receives light emitted from a light source 11, an exit surface 3 that emits light incident on the incident surface 2, regions 2a, 3a (first regions) formed on the incident surface 2 and the exit surface 3, respectively, to irradiate a first light toward the traveling direction S1 of the road 21, and regions 2b, 3b (second regions) formed on the incident surface 2 and the exit surface 3, respectively, to irradiate a second light, which is more diffused than the first light, toward the side opposite the traveling direction S1 of the road 21.

As a result, the illuminance of the lighting device 10 on the side of the lane 23 facing the direction of travel S1 is increased, improving the visibility of drivers of vehicles traveling in the direction of travel S1. Furthermore, the illuminance of the lighting device 10 on the side of the lane 23 facing the opposite direction of travel S1 is reduced, reducing glare for drivers of vehicles traveling in the direction of travel S1. Therefore, glare can be reduced while widening the illumination range of the lighting device on the lane 23.

In addition, regions 2a and 3a are formed on the incident surface 2 and the exit surface 3 closer to the direction of travel S1 of the road 21 than regions 2b and 3b, respectively. As a result, regions 2a and 2b are formed on the side of the incident surface 2 that corresponds to the direction of light irradiation, and regions 3a and 3b are formed on the side of the exit surface 3 that corresponds to the direction of light irradiation, thereby simplifying the configuration of the lighting lens 1.

The road 21 also includes a lane 23 (first lane) and a lane 25 (second lane) that is an oncoming lane to lane 23. Regions 2a and 3a are formed to irradiate a first light toward the traveling direction S1 of lane 23, and regions 2b and 3b are formed to irradiate a second light toward the side opposite to the traveling direction S1 of lane 23. The illumination lens 1 is provided with regions 2d and 3d (third regions) formed on the incident surface 2 and the exit surface 3, respectively, to irradiate a third light toward the traveling direction S2 of lane 25, and regions 2c and 3c (fourth regions) formed on the incident surface 2 and the exit surface 3, respectively, to irradiate a fourth light, which is more diffused than the third light, toward the side opposite to the traveling direction S2 of lane 25.

As described above, this configuration allows the lighting device to expand its illumination range while reducing glare in lane 23.

In addition, in lane 25, the illuminance of lighting device 10 on the side facing the direction of travel S2 is increased, improving the visibility of drivers of vehicles traveling in the direction of travel S2. In addition, in lane 25, the illuminance of lighting device 10 on the side opposite the direction of travel S2 is decreased, reducing glare for drivers of vehicles traveling in the direction of travel S2. Therefore, even in lane 25, which is the opposite lane to lane 23, glare can be reduced while expanding the illumination range of the lighting device.

In addition, regions 2c and 3c are formed on the incident surface 2 and the exit surface 3 closer to the direction of travel S1 of the lane 23 than regions 2d and 3d, respectively. As a result, regions 2c and 2d are formed on the side of the incident surface 2 that corresponds to the direction of light irradiation, and regions 3c and 3d are formed on the side of the exit surface 3 that corresponds to the direction of light irradiation, thereby simplifying the configuration of the lighting lens 1.

In addition, regions 2a, 3a and regions 2b, 3b are each separated by axis Z1 (first axis) extending in the Z direction, and regions 2c, 3c and regions 2d, 3d are each separated by axis Z1. Regions 2a, 3a and regions 2c, 3c are each separated by axis X1 (second axis) extending in the X direction, and regions 2b, 2b and regions 2d, 3d are each separated by axis X1. This simplifies the configuration of the illumination lens 1.

The lighting system according to this embodiment also includes a plurality of lighting devices 10. The lighting devices 10 are arranged along the road 21 in a staggered arrangement in the direction of travel of the road 21. This allows the number of lighting devices 10 installed on the road 21 to be reduced while still thoroughly illuminating the road surface of the road 21.

(Other embodiments)
As described above, the embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate.

Note that the manner in which the regions in the lighting lens 1 are divided is not limited to that shown in Figure 1. For example, the lighting device 10 can use the lighting lens 1a shown in Figure 13. Specifically, regions 2a and 2b are divided by axis Z2, which forms an angle θ2 (first angle) with axis Z1. Similarly, regions 2c and 2d are divided by axis Z2. Furthermore, regions 2a and 2c are divided by axis Z3, which forms an angle θ3 (second angle) with axis Z1. Similarly, regions 2b and 2d are divided by axis Z3. As long as the lighting lens 1a can achieve the light distribution of the lighting lens 1 in Figure 7, angles θ2 and θ3 may be set in any way.

Furthermore, as long as the light distribution (illuminance distribution) of the illumination lens 1 in Figure 7 can be realized, the configuration of the illumination lens is not limited to Figures 1 and 13. For example, in Figure 1, the axis separating areas 2a and 2c and the axis separating areas 2b and 2d are the same axis X1, but these axes may be offset in the Z direction. Similarly, the axis separating areas 2a and 2b and the axis separating areas 2c and 2d are the same axis Z1, but these axes may be offset in the X direction.

1 and 13, regions 2a-2d and regions 3a-3d are formed on the incident surface 2 and the exit surface 3, but this is not limited to this. For example, the illuminance distribution of the illumination lens 1 shown in FIG. 7 can also be achieved by forming only either regions 2a-2d or regions 3a-3d on the illumination lens 1.

In addition, in the above embodiment, two lanes (lanes 23 and 25) are formed on road 21, but lighting lens 1 can also be applied when only one lane is formed on road 21. For example, when only lane 23 is formed on road 21, the illuminance distribution of lighting lens 1 shown in Figure 7 can be achieved by omitting areas 2c, 2d, 3c, and 3d.

In addition, in the above embodiment, the lighting device 10 was described as being installed in a tunnel 22, but it may also be installed on the side of a road and irradiate light onto the road.

Figure 14 is a perspective view showing another example of an illumination lens according to this embodiment, and Figure 15 is a cross-sectional view of an illumination device using the illumination lens of Figure 14. As shown in Figures 14 and 15, illumination device 10c comprises a plurality of light sources 11 and illumination lens 1b in which a plurality of illumination lenses 1 are arranged in an array. The plurality of illumination lenses 1 provided on illumination lens 1b are respectively arranged to correspond to the plurality of light sources 11. By arranging the illumination lenses 1 in an array, illumination device 10 is able to emit stronger light.

Figures 16A to 16C are plan views showing illuminance distributions for other examples of illumination lenses according to this embodiment. Illumination lens 1c has illuminance distribution 30a as shown in Figure 16A, and illumination lens 1d has illuminance distribution 30b as shown in Figure 16B. In this case, by providing illumination lenses 1b and 1c with different illuminance distributions in illumination device 10, the light emitted from illumination lenses 1c and 1d is superimposed, achieving illuminance distribution 30c as shown in Figure 16C. In this case, as shown in Figure 16B, illumination device 10 may also be provided with illumination lens 1d whose illuminance distribution is symmetrical in a plan view. Note that the illuminance distribution does not necessarily have to be symmetrical; two or more types of lenses with different illuminance distributions, including asymmetric distributions, may be combined and arranged in the array shown in Figure 14.

According to one aspect of the present invention, it is possible to reduce glare while expanding the illumination range of the lighting device.

The lighting device and lighting system of the present invention can be installed, for example, inside tunnels or on roadsides, thereby reducing the number of lighting devices that need to be installed.

1 (1a to 1d) Illumination lens 2 Incident surface 3 Output surface 2a to 2d, 3a to 3d Area 10 (10a to 10c) Illumination device 11 Light source 21 Road 23, 25 Lane 24 Center line 23a, 23b, 25a, 25b Road surface S1, S2 Direction of travel

Claims (8)

A lighting lens used in a lighting device installed on a road,
The lighting lens is arranged so that the front direction of the lighting lens is perpendicular to the parallel direction that is the direction along the road traveling direction,
an incident surface that receives light emitted from the light source;
an exit surface that emits light incident on the entrance surface;
a first region formed on at least one of the incident surface and the exit surface so as to irradiate a first light toward a traveling direction of the road;
a second region formed on at least one of the incident surface and the exit surface so as to irradiate a second light, the second light being more diffused than the first light, toward an opposite side of the road in a traveling direction;
Equipped with
the road includes a first lane and a second lane that is an oncoming lane of the first lane,
the first area is formed to irradiate the first light toward the first lane in the traveling direction,
the second area is formed to irradiate the second light in a direction opposite to a traveling direction of the first lane,
The lighting lens is
a third region formed on at least one of the incident surface and the exit surface so as to irradiate a third light toward the traveling direction of the second lane;
a fourth region formed on at least one of the incident surface and the exit surface so as to irradiate a fourth light, which is light more diffused than the third light, toward an opposite side to the traveling direction of the second lane;
Further equipped
A lighting lens characterized by: 2. The lighting lens according to claim 1 ,
the first area is formed on the incident surface and the exit surface on a traveling direction side of the first lane relative to the second area,
The illumination lens, wherein the fourth area is formed on the entrance surface and the exit surface closer to the first lane in a traveling direction than the third area. The lighting lens of claim 2 ,
the first and second regions are separated by a first axis extending in a vertical direction perpendicular to the front direction and the parallel direction,
the third and fourth regions are separated by the first axis;
the first and fourth regions are separated by a second axis extending in the parallel direction;
The illumination lens, wherein the second and third regions are separated by the second axis. The lighting lens of claim 2 ,
the first and second regions are separated by a third axis extending in a direction forming a first angle with a vertical direction perpendicular to the front direction and the parallel direction,
the third and fourth regions are separated by the third axis;
the first and fourth regions are separated by a fourth axis extending in a direction forming a second angle with the vertical direction;
The illumination lens, wherein the second and third regions are separated by the fourth axis. a light source having a light-emitting element;
An illumination device comprising: the illumination lens according to any one of claims 1 to 4 . 6. The lighting device according to claim 5 ,
a plurality of the illumination lenses;
The lighting device, wherein the plurality of lighting lenses have different illuminance distributions. A plurality of the lighting devices according to claim 5 or 6 are provided,
The lighting system according to claim 1, wherein the plurality of lighting devices are arranged along the road in a staggered arrangement in a direction of travel of the road. 2. The lighting device according to claim 1 , wherein the third light is parallel light.