JP7774015B2 - Luminous studs and lens components - Google Patents

Description

The present invention relates to a light-emitting stud and a lens member.

In recent years, self-illuminating road studs have been proposed that can be used on inclined surfaces at low heights and efficiently emit light from light-emitting diodes (see, for example, Patent Document 1).

The self-illuminating road stud described in Patent Document 1 has a translucent body attached to the top opening of the stud body buried in the road surface, and a light-emitting diode attached to the bottom of the translucent body. The translucent body is buried flush with the road surface and has a flat top surface on which a protrusion with a trapezoidal cross section is formed, with the inclined side forming the protrusion being an inclined surface that emits light from the light-emitting diode to the outside. An incident surface is formed at the bottom of the translucent body opposite the light-emitting surface of the light-emitting diode, and light from the light-emitting diode that enters the translucent body from the incident surface is refracted downward by the inclined surface and emitted to the outside. The light-emitting diode is a side-view light-emitting diode with a horizontally elongated light-emitting surface that emits light in a direction parallel to the mounting surface.

Japanese Patent Application Laid-Open No. 2007-303141

However, with conventional self-luminous road studs, the light emitted from the light-emitting diode has a wide light distribution angle, and because this light is incident directly on the incident surface of the translucent body, the light emitted from the light-emitting diode cannot be efficiently incident on the incident surface, making it difficult for the light to reach a distant vehicle driver. Furthermore, because the elevation angle of the light emitted to the outside is small, it is not suitable for use in applications where it is visible to pedestrians nearby (for example, within 10 meters).

Therefore, the objective of the present invention is to provide luminous studs and lens members that can improve visibility depending on the application.

In order to solve the above-mentioned problems, the present invention provides a lens element comprising a light source arranged at a predetermined position, and which imparts predetermined light distribution characteristics to light emitted from the light source and outputs the light to the outside. The lens element has a rear-side protrusion that protrudes in an inverted trapezoidal cross section from a central region of the rear side, and a front-side protrusion that protrudes in a trapezoidal cross section from a central region of the front side, and is embedded in an installation surface so that the front-side protrusion is exposed to the front side. The side of the rear-side protrusion that is on the side where the light source is arranged serves as an incident surface with an inclined surface onto which light from the light source is incident, and the side of the front-side protrusion that is on the opposite side to the side where the light source is arranged serves as an incident surface for directing light that has entered the incident surface to the outside. and a lens member having an exit surface with an inclined surface for emitting light, wherein the light source is configured to be positionable at any one of four predetermined positions in the X direction and the Y direction which are orthogonal to each other in a plan view, and the lens member is configured so that the entrance surface of the rear-side protrusion is formed in the X direction and the Y direction, respectively, and the exit surface of the front-side protrusion is formed in the X direction and the Y direction, respectively, and the optical path length from the entrance surface formed in the X direction to the exit surface is longer than the optical path length from the entrance surface formed in the Y direction to the exit surface.

To achieve the above object, the present invention also provides a lens element having a back-side protrusion that protrudes in an inverted trapezoidal cross section from a central region of the back side, and a front-side protrusion that protrudes in a trapezoidal cross section from a central region of the front side, wherein the side of the inverted trapezoidal cross section of the back-side protrusion serves as an incident surface with a slope onto which light enters, and the side of the trapezoidal cross section of the front-side protrusion that faces the incident surface serves as an exit surface with a slope from which light that has entered the incident surface exits, the incident surfaces of the back-side protrusions are formed in the X direction and the Y direction, which are orthogonal to each other in a plan view, and the exit surfaces of the front-side protrusions are formed in the X direction and the Y direction, respectively, and the optical path length from the incident surface formed in the X direction to the exit surface is longer than the optical path length from the incident surface formed in the Y direction to the exit surface.

This invention allows for improved visibility depending on the application.

FIG. 1 is a perspective view showing an example of the appearance of a light-emitting stud according to an embodiment of the present invention. FIG. 2 is a plan view of the light-emitting stud shown in FIG. FIG. 3 shows an example of a cover lens, where (a) is a perspective view seen from the back side, and (b) is a perspective view seen from the front side. FIG. 4 is a perspective view showing an example of the internal structure of the light-emitting stud shown in FIG. 1 with the cover lens removed. FIG. 5 is a plan view showing an example of a substrate on which a light source is mounted. FIG. 6 is a cross-sectional view taken along line AA in FIG. 2, showing an example of an optical system for a vehicle. FIG. 7 is a cross-sectional view taken along line BB in FIG. 2, showing an example of an optical system for pedestrians. FIG. 8 is a diagram showing the results of a simulation of the light distribution characteristics in a plan view. FIG. 9 is a diagram showing the simulation results of the light distribution characteristics on a plane perpendicular to the X direction. FIG. 10A is a diagram showing the simulation results of the light distribution characteristics in a plane perpendicular to the Y direction, and FIG. 10B is a diagram showing the simulation results of the light distribution characteristics in a plane perpendicular to the Y direction according to a modified example. FIG. 11 is a diagram showing the light intensity distribution in the X direction. FIG. 12 is a diagram showing the light intensity distribution in the Y direction. FIG. 13 is a cross-sectional view corresponding to the cross-sectional view taken along line BB in FIG. 2 according to the first modification. FIG. 14 is a diagram showing the light intensity distribution in the Y direction according to the first modification. FIG. 15 is a diagram schematically illustrating an installation example 1 of the light-emitting tack according to the present embodiment. FIG. 16 is a diagram schematically illustrating an installation example 2 of the light-emitting tack according to this embodiment. FIG. 17 is a diagram schematically illustrating an installation example 3 of the light-emitting tack according to the present embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that in each drawing, components having substantially the same functions will be assigned the same reference numerals and redundant explanations will be omitted. Furthermore, in this embodiment, a luminous stud that can be used for both vehicles and pedestrians will be described, but the present invention is not limited to this.

[Embodiment]
Fig. 1 is a perspective view showing an example of the appearance of a luminous stud according to an embodiment of the present invention, and Fig. 2 is a plan view of the luminous stud shown in Fig. 1.

As shown in Figure 1, this light-emitting stud 1 comprises a housing 2 embedded in a predetermined installation surface 12 (see Figures 6 and 7), and a cover lens 3 that imparts predetermined light distribution characteristics according to the light emission direction to light emitted from a light source 6 (see Figure 4, etc.) housed in a predetermined position within the housing 2, and emits light to the outside, for example, light 10x for vehicles in the X direction, light 10y for pedestrians in the Y direction, and light 10z for pedestrians upward in the Z direction (not shown in Figures 1 and 2). The cover lens 3 is an example of a lens member.

Note that light 10x for vehicles and light 10y for pedestrians are shown schematically in Figures 1 and 2. Hereinafter, light 10x for vehicles and light 10y for pedestrians are collectively referred to as "light 10." The emission direction of light 10 is not limited to the direction shown in Figure 1. For example, it may be one, two, or three of the four directions of the X and Y directions, or may include directions other than the four directions of the X and Y directions. Furthermore, whether emitted light 10 is light 10x for vehicles or light 10y for pedestrians can be arbitrarily modified depending on the application. For example, light 10x for vehicles may be emitted in the X and Y directions, and light 10y for pedestrians may be emitted in the X and Y directions.

The luminous studs 1 may be installed on, for example, center lines, lane lines, outer road lines (side road white lines), crosswalks, stop lines, intersections, curbs, etc., but are not limited to these.

As shown in Figure 2, the cover lens 3 has a roughly octagonal, disk-like shape. A trapezoidal front protrusion 31 is formed in the central region of the cover lens 3. Light 10x for vehicles is emitted in the X direction from emission surfaces 31xa and 31xb on the side surfaces of the front protrusion 31, and light 10y for pedestrians is emitted in the Y direction from emission surfaces 31ya and 31yb on the side surfaces of the front protrusion 31. The X-direction emission surfaces 31xa and 31xb of the cover lens 3 are formed as curved surfaces convex toward the emission side in a plan view, and the Y-direction emission surfaces 31ya and 31yb are formed as linear surfaces in a plan view.

(Configuration of cover lens)
Fig. 3 shows an example of a cover lens 3, with (a) being a perspective view seen from the back side and (b) being a perspective view seen from the front side. Fig. 3(b) is a perspective view seen from the front side, similar to the cover lens 3 shown in Fig. 1. Fig. 3(a) is a perspective view of the cover lens 3 shown in Fig. 3(b) rotated 180° around the axis in the Y direction, seen from the back side.

As shown in Figure 3(a), the cover lens 3 has a back-side protrusion 30 that protrudes in an inverted trapezoidal cross section (i.e., the X-Z cross section and the Y-Z cross section are trapezoidal) in the central region of the back side, and as shown in Figure 3(b), a front-side protrusion 31 that protrudes in an inverted trapezoidal cross section (i.e., the X-Z cross section and the Y-Z cross section are trapezoidal) in the central region of the front side, with a peripheral portion 32 of approximately uniform thickness surrounding the back-side protrusion 30 and the front-side protrusion 31. The cover lens 3 is made of a light-transmitting material such as acrylic resin or polycarbonate resin.

The two side surfaces of the inverted trapezoidal shape of the rear protrusion 30 in the X-Z cross section are sloped incident surfaces 30xa and 30xb onto which light from the light source 6 is incident, and the two side surfaces of the inverted trapezoidal shape of the rear protrusion 30 in the Y-Z cross section are sloped incident surfaces 30ya and 30yb onto which light from the light source 6 is incident. In other words, the cover lens 3 has the incident surfaces 30xa, 30xb, 30ya, and 30yb of the rear protrusion 30 formed in the X and Y directions, respectively.

The trapezoidal side surfaces of the front-side protrusion 31 in the X-Z cross section are sloped emission surfaces 31xa and 31xb, and the trapezoidal side surfaces of the front-side protrusion 31 in the Y-Z cross section are sloped emission surfaces 31ya and 31yb. In other words, the cover lens 3 has the emission surfaces 31xa, 31xb, 31ya, and 31yb of the front-side protrusion 31 formed in the X and Y directions, respectively.

Note that trapezoidal and inverted trapezoidal shapes include not only isosceles trapezoidal shapes, but also shapes with one sloped surface and one non-sloped surface, and shapes in which the intersection line (ridge line) between the side surface and the top surface, or the intersection line between the side surface and the periphery of the rear protrusion 30 and front protrusion 31, is formed in an arc-shaped cross section.

(Internal structure of the luminous stud)
Fig. 4 is a perspective view showing an example of the internal structure of the light-emitting stud 1 shown in Fig. 1 when the cover lens 3 is removed. The housing 2 houses a case 4 and a substrate 5.

On the upper surface of the substrate 5, there are arranged light sources 6, including vehicle light sources 6Aa and 6Ab, first pedestrian light sources 6Ba and 6Bb, and second pedestrian light sources 6Ca and 6Cb; a concentrating lens 7A that focuses light emitted from the vehicle light sources 6Aa and 6Ab and directs it in a predetermined direction, i.e., onto the incident surfaces 30xa and 30xb of the cover lens 3; a concentrating lens 7B that focuses light emitted from the first pedestrian light sources 6Ba and 6Bb and directs it onto the incident surfaces 30ya and 30yb of the cover lens 3; and a rod lens 8 that directs light emitted from the second pedestrian light sources 6Ca and 6Cb upward in the Z direction through the peripheral portion 32 of the cover lens 3. The second pedestrian light sources 6Ca and 6Cb are an example of an upward-emitting light source. The concentrating lenses 7A and 7B are an example of a concentrating member.

The rod lens 8 has a cylindrical shape, with one end face serving as an entrance end face where light enters and the other end face serving as an exit end face 8a where light exits. Note that the vehicle light sources 6Aa, 6Ab, the first pedestrian light sources 6Ba, 6Bb, and the second pedestrian light sources 6Ca, 6Cb are also collectively referred to as the vehicle light source 6A, the first pedestrian light source 6B, and the second pedestrian light source 6C, respectively.

(Light source configuration)
5 is a plan view showing an example of a substrate 5 on which a light source 6 is mounted. The light source 6 is configured to be able to be arranged at any of four predetermined positions on the substrate 5 in the X direction and the Y direction, which are orthogonal to each other in a plan view. For example, a pair of vehicle light sources 6Aa, 6Ab are mounted at predetermined positions in the X direction on the upper surface 5a of the substrate 5, and a pair of first pedestrian light sources 6Ba, 6Bb are mounted at predetermined positions in the Y direction on the upper surface 5a of the substrate 5. Furthermore, a pair of second pedestrian light sources 6Ca, 6Cb are mounted at predetermined positions in the Y direction on the upper surface 5a of the substrate 5.

The substrate 5 is, for example, a printed circuit board, and has a wiring pattern made of metal such as copper foil formed on the surface of an insulating substrate such as a glass substrate or an epoxy-based or polyester-based composite substrate, for supplying power to the light source 6, etc.

The vehicle light sources 6Aa, 6Ab are composed of, for example, five multicolor LEDs 60 and five white LEDs 61, with the multicolor LEDs 60 and white LEDs 61 arranged alternately and closely to each other along the Y direction. The multicolor LEDs 60 are an example of a multicolor light-emitting element. The white LEDs 61 are an example of a white light-emitting element. Note that the light-emitting elements that make up the vehicle light sources 6Aa, 6Ab are not limited to those described above.

The multicolor LED 60 incorporates a red LED that emits reddish light, a green LED that emits greenish light, and a blue LED that emits blueish light. The white LED 61, for example, converts the blueish light emitted from the blue LED into yellowish light using a phosphor, and then emits whiteish light by mixing the yellowish light and blueish light. By mounting the light-emitting elements that make up the vehicle light source 6A with a high mounting density as described above and improving the light emission intensity, the vehicle light 10x can reach long distances (e.g., 100 m or more) and can be selectively turned on to emit light of various colors or mixed colors.

If the multicolor LED 60 has three elements and the white LED 61 has one element, then in Figure 5, 20 light-emitting elements are mounted over the length of the area in which the light-emitting elements are mounted (e.g., 24 mm). The mounting density in the case shown in Figure 5 can be expressed as 20 elements/24 mm = 0.83 elements/mm, and the preferred mounting density can be expressed as 0.6 to 1 element/mm.

The first pedestrian light sources 6Ba, 6Bb are composed of, for example, two multicolor LEDs 60 and two white LEDs 61, with the multicolor LEDs 60 and white LEDs 61 arranged alternately along the X direction. The second pedestrian light sources 6Ca, 6Cb are composed of, for example, one multicolor LED 60 and one white LED 61, and are arranged outside the first pedestrian light sources 6Ba, 6Bb. Note that the light-emitting elements that make up the first pedestrian light source 6B and the second pedestrian light source 6C are not limited to those described above.

A vehicle light-emitting stud can be made by using only the vehicle light source 6A as the light source 6, or a pedestrian light-emitting stud can be made by using only the first pedestrian light source 6B and the second pedestrian light source 6C as the light source 6. This makes it possible to share the housing 2, cover lens 3, case 4, substrate 5, light source 6, etc. between the vehicle light-emitting stud and the pedestrian light-emitting stud.

(Configuration of the vehicle optical system)
Fig. 6 is a cross-sectional view of an example of a vehicle optical system taken along line A-A in Fig. 2. Note that Fig. 6 does not show the pedestrian optical system (first pedestrian light source 6B, second pedestrian light source 6C, condenser lens 7B, and rod lens 8).

The light-emitting stud 1 comprises a housing 2 embedded in the installation surface 12 so that the front protrusion 31 is exposed on the front side, a case 4 housed in the housing 2, a board 5 arranged horizontally within the case 4, a vehicle light source 6A mounted on the top surface 5a of the board 5 and having an optical axis 6a perpendicular to the board 5, and a focusing lens 7A that focuses the light emitted from the vehicle light source 6A.

The housing 2 has a lower recess 20 that houses the case 4, and an upper recess 21 that receives the cover lens 3 on a receiving surface 21a and houses the cover lens 3. Furthermore, a wall 22 that forms the lower recess 20 of the housing 2 is formed with a screw hole 21b for fixing the cover lens 3 with a bolt 11. A ring-shaped packing groove 21c that houses a packing 13 is formed on the receiving surface 21a of the housing 2, and watertightness is ensured by the close contact between the packing 13 and the receiving surface 32a of the cover lens 3. The housing 2 is made of a metal such as aluminum or an aluminum alloy.

To ensure internal storage space, the cover lens 3 is not supported in the center but is supported by a peripheral receiving surface 32a in the central area on the back side. Specifically, the receiving surface 32a on the back side of the peripheral portion 32 of the cover lens 3 is supported by the receiving surface 21a of the housing 2, and the peripheral portion 32 of the cover lens 3 is fixed to the housing 2 with bolts 11 via through-holes 32c in recessed seats 32b formed in the peripheral portion 32. Furthermore, the cover lens 3 has recesses 33 formed in the rear projections 30 so as not to obstruct the optical path from the incident surfaces 30xa and 30xb to the exit surfaces 31xa and 31xb. These recesses 33 avoid interference with components mounted on the substrate 5, such as a motion sensor or solar cell.

In addition, to suppress road noise generated when a vehicle passes over the cover lens 3, the height Hf (e.g., approximately 5 mm) to the top surface 31a of the front-side protrusion 31 of the cover lens 3 is set as low as possible. In relation to the height of the front-side protrusion 31, in order to increase the efficiency of incidence onto the incident surfaces 30xa and 30xb, the receiving surface 32a is located closer to the front than the top surface 30a of the rear-side protrusion 30, and the height Hr (e.g., approximately 6 mm) to the top surface 30a of the rear-side protrusion 30 is set higher than the height Hf to the top surface 31a of the front-side protrusion 31. This makes it easier to position the exit surface 72 (described below) of the condenser lens 7A opposite the incident surfaces 30xa and 30xb, thereby increasing the efficiency of incidence from the exit surface 72 to the incident surfaces 30xa and 30xb.

Furthermore, in the cover lens 3, the incident surfaces 30xa, 30xb and the exit surfaces 31xa, 31xb formed in the X direction, and the incident surfaces 30ya, 30yb and the exit surfaces 31ya, 31yb formed in the Y direction, are positioned opposite each other so that the cover lens 3 emits the vehicle light 10x to the outside at a lower angle than the pedestrian light 10y. The optical path length from the incident surfaces 30xa, 30xb to the exit surfaces 31xa, 31xb is longer than the optical path length from the incident surfaces 30ya, 30yb to the exit surfaces 31ya, 31yb. In relation to this optical path length between the incident and exit surfaces, the thickness _T1 of the central region where the recess 33 is formed may be made equal to or greater than the thickness _T2 of the peripheral portion 32 to prevent damage or deformation when a vehicle passes over the cover lens 3. Note that the recess 33 may not be provided depending on the strength of the cover lens 3 and the components mounted on the substrate 5.

The case 4 has a recess 40 that houses the substrate 5 and a support portion 41 whose upper surface 41a contacts the lower surface 5b of the substrate 5 to support the substrate 5. From the perspective of ensuring insulation, the case 4 is preferably formed by injection molding using a resin such as polycarbonate resin. The case 4 may also be formed from a metal such as aluminum or an aluminum alloy.

The condensing lens 7A has an incident surface 70a whose cross-sectional shape is formed by a curved convex toward the vehicle light source 6A; a reflective surface 71a formed by a curved surface that totally reflects the light incident on the incident surface 70a and converts it into approximately parallel light; and an exit surface 72a that emits the light reflected by the reflective surface 71a in a direction different from the optical axis 6a of the light source 6. The reflective surface 71a is, for example, formed by one or more outwardly convex curved surfaces so that the incident light is totally reflected and converted into approximately parallel light. The condensing lens 7A is formed from a light-transmitting material such as acrylic resin or polycarbonate resin.

In the vehicle optical system configured as described above, light emitted from the vehicle light source 6Aa is focused by the incident surface 70a of the focusing lens 7A, reflected by the reflecting surface 71a, and then emitted from the exit surface 72a and incident on the incident surface 30xa of the cover lens 3. Most of the light incident on the incident surface 30xa reaches the exit surface 31xa without being totally reflected by the top surface 31a of the front protrusion 31, and is emitted to the outside from the exit surface 31xa at a low angle as vehicle light 10x.

Similarly, light emitted from vehicle light source 6Ab is focused by focusing lens 7A and enters incident surface 30xb. Most of the light that enters incident surface 30xb reaches exit surface 31xb without being totally reflected by top surface 31a of front protrusion 31, and is emitted to the outside at a low angle from exit surface 31xb as vehicle light 10x.

(Configuration of optical system for pedestrians)
Fig. 7 is a cross-sectional view showing an example of an optical system for pedestrians taken along line BB in Fig. 2. Note that Fig. 7 does not show the optical system for vehicles (vehicle light source 6A, condenser lens 7A).

As described above, the light-emitting stud 1 comprises a housing 2 embedded in the installation surface 12, a case 4 housed in the housing 2, and a substrate 5 arranged horizontally within the case 4. It also comprises first pedestrian light sources 6Ba, 6Bb and second pedestrian light sources 6Ca, 6Cb mounted on the upper surface 5a of the substrate 5 and having optical axes 6a perpendicular to the substrate 5, a focusing lens 7B that focuses and reflects light emitted from the first pedestrian light sources 6Ba, 6Bb, and a rod lens 8 that focuses and emits light emitted from the second pedestrian light sources 6Ca, 6Cb to the outside.

The focusing lens 7B has an incident surface 70b whose cross-sectional shape is formed by a curved convex toward the first pedestrian light source 6B; a reflective surface 71b formed by a curved surface that totally reflects and focuses the light incident on the incident surface 70b; and an exit surface 72b that emits the light reflected by the reflective surface 71b in a direction different from the optical axis 6a of the light source 6. The reflective surface 71b is, for example, configured with one or more outwardly convex curved surfaces that totally reflect and focus the incident light. The reason why the reflective surface 71b of the focusing lens 7B of the pedestrian optical system has higher light-focusing properties than the reflective surface 71a of the focusing lens 7A of the vehicle optical system is that the optical path length from the incident surfaces 30ya, 30yb of the pedestrian optical system to the exit surfaces 31ya, 31yb is shorter than the optical path length from the incident surfaces 30xa, 30xb of the vehicle optical system to the exit surfaces 31xa, 31xb. The condenser lens 7B is made of a light-transmitting material such as acrylic resin or polycarbonate resin.

In the pedestrian optical system configured as described above, light emitted from the first pedestrian light source 6Ba is focused by the incident surface 70b of the focusing lens 7B, reflected and focused by the reflecting surface 71b, and then exits from the exit surface 72b and enters the incident surface 30ya of the cover lens 3. Most of the light incident on the incident surface 30ya reaches the exit surface 31ya without being totally reflected by the top surface 31a of the front-side protrusion 31, and is emitted to the outside from the exit surface 31ya as pedestrian light 10y.

Similarly, light emitted from the first pedestrian light source 6Bb is focused by the focusing lens 7B and enters the incident surface 30yb. Most of the light that enters the incident surface 30yb reaches the exit surface 31yb without being totally reflected by the top surface 31a of the front protrusion 31, and is emitted from the exit surface 31yb to the outside as pedestrian light 10y. Light emitted from the second pedestrian light sources 6Ca and 6Cb enters the incident end surface of the rod lens 8 and is emitted upward in the Z direction from the exit end surface 8a of the rod lens 8 via the peripheral portion 32 of the cover lens 3 as pedestrian light 10z.

(Light distribution characteristics in plan view)
FIG. 8 shows the results of a simulation of the light distribution characteristics in a plan view. Note that the second pedestrian light source 6C is not taken into consideration. As described in FIG. 2 , the X-direction exit surfaces 31xa and 31xb of the cover lens 3 are curved surfaces convex toward the exit side in a plan view, and have a straight vertical cross section. On the other hand, the Y-direction exit surfaces 31ya and 31yb are linear surfaces in a plan view, and have a straight vertical cross section. Therefore, according to the simulation results, the light distribution angle θxy of the vehicle light 10x emitted in the X direction in a plan view is narrow at 48°, while the light distribution angle θyx of the pedestrian light 10y emitted in the Y direction is wide at 77°. Note that in a simulation where the exit surfaces 31xa and 31xb are linear surfaces in a plan view, the light distribution angle θxy of the vehicle light 10x in a plan view is wide at 63°.

The light 10x for vehicles emitted from the light-emitting stud 1 in the X direction has a narrow light distribution angle θxy of 50° or less in a planar view, resulting in concentrated light rays and high light intensity, making it easier to reach long distances (e.g., 100 m or more). The light 10y for pedestrians emitted from the light-emitting stud 1 in the Y direction has a wide angle of 70° or more in a planar view, making it easier for pedestrians to see the light 10y from close by (e.g., within 10 m). Furthermore, because the rod lens 8 emits the light 10z for pedestrians upward in the Z direction, the light 10z is easier to see from pedestrians walking nearby (e.g., 0 to 3 m). In other words, this light-emitting stud 1 can improve visibility not only for pedestrians in the vicinity (e.g., around 10 m) but also for pedestrians in the immediate vicinity (e.g., 0 to 3 m).

(Light distribution characteristics in vertical plane for vehicles)
9 is a diagram showing the results of a simulation of the light distribution characteristics in a vertical plane in the X direction. Note that the first pedestrian light source 6B and the second pedestrian light source 6C are not taken into consideration in this figure. According to the simulation results, the light distribution angle θxz in the vertical plane of the vehicle light 10x emitted in the X direction from the light-emitting stud 1 is 4.5° (θx1 = 0.5°, θx2 = 5°). As described above regarding the light distribution characteristics of the vehicle light, by mounting the light-emitting elements constituting the vehicle light source 6A at a high mounting density, improving the incidence efficiency of the incident surfaces 30xa and 30xb of the cover lens 3, and forming the exit surfaces 31xa and 31xb as curved surfaces that are convex toward the exit side in a plan view, it is possible to narrow the light distribution angles θxy and θxz of the vehicle light 10x, thereby making it possible for the vehicle driver to see the vehicle light 10x from a distance (e.g., 100 m or more). Furthermore, narrowing the light distribution angle θx2 in the vertical plane of the light 10x for vehicles can prevent pedestrians walking nearby (for example, within 10 m) from feeling dazzled.

(Light distribution characteristics for pedestrians)
10(a) is a diagram showing the results of a simulation of light distribution characteristics in a vertical plane in the Y direction. Note that this simulation was performed only for one of the first pedestrian light sources 6Ba, and the vehicle light source 6A and the second pedestrian light source 6C were not taken into consideration. As shown in FIG. 10(a), the exit surfaces 31ya and 31yb of the cover lens 3 have a vertical cross-sectional shape formed by a curve convex toward the exit side, and have a point 10ya outside the curve where light rays incident on the entrance surfaces 30ya and 30yb intersect. The exit surfaces 31ya and 31yb, whose vertical cross-sectional shape is formed by a curve convex toward the exit side, are an example of a diffusion means.

According to the simulation results, the light distribution angle θyz in the vertical plane of the pedestrian light 10y emitted in the Y direction from the light-emitting stud 1 was 28° (θy1 = 5°, θy2 = 33°). Because the light distribution angle θyz in the vertical plane of the pedestrian light 10y emitted in the Y direction from the light-emitting stud 1 is wide, the pedestrian light 10y can be seen by pedestrians, including children and adults, who are near the light-emitting stud 1 (for example, within 10 m). Furthermore, by forming the vertical cross-sectional shape of the emission surfaces 31ya, 31yb into a curve that is convex on the emission side, damage to the corners between the emission surfaces 31ya, 31yb and the top surface 31a when a vehicle passes over the cover lens 3 can be reduced, compared to when the vertical cross-sectional shape is a curve that is concave on the emission side.

Figure 10(b) shows the results of a simulation of the light distribution characteristics in a vertical plane in the Y direction for a modified version of the exit surfaces 31ya and 31yb. In this modified version, the exit surfaces 31ya and 31yb of the cover lens 3 have a vertical cross-sectional shape that is concavely curved toward the exit side, as shown in Figure 10(b). Exit surfaces 31ya and 31yb, whose vertical cross-sectional shape is formed by a concavely curved shape toward the exit side, are an example of a diffusion means.

Simulation results showed that the light distribution angle θ'yz in the vertical plane of pedestrian light 10y emitted in the Y direction from light-emitting stud 1 was 22° (θ'y1 = 2°, θ'y2 = 24°). With this modification, the light distribution angle in the vertical plane is slightly narrower than when the exit surfaces 31ya, 31yb are curved convexly toward the exit side in the vertical cross section, but it is possible to emit light at a wider light distribution angle θ'yz than vehicle light 10x. Note that the vertical cross section of the entrance surfaces 30ya, 30yb may be configured with a curved convex or concave toward the exit side as a diffusing means. Furthermore, diffusing means may be provided in any of the optical paths from the light source 6 to the exit surfaces 31ya, 31yb of the cover lens 3, and diffuse the light passing through the optical path in the vertical plane.

(light intensity distribution)
FIG. 11 is a diagram showing the light intensity distribution in the X direction. FIG. 11(a) shows the light intensity distribution in a plan view in the X direction, and FIG. 11(b) shows the light intensity distribution in a plane perpendicular to the X direction. FIG. 12 is a diagram showing the light intensity distribution in the Y direction. FIG. 12(a) shows the light intensity distribution when the elevation angle in the Y direction relative to the horizontal is 6°, and FIG. 12(b) shows the light intensity distribution when the elevation angle in the Y direction relative to the horizontal is 20°. FIG. 12(c) shows the light intensity distribution in a plane perpendicular to the Y direction. Note that the relative light intensity (%) shown in FIG. 12(c) is based on the maximum light intensity (100% in FIG. 11(b)) of the light intensity in all directions. Note that FIGS. 11 and 12 show the light intensity distribution when only the vehicle light source 6A is used as the light source 6.

As explained in Figure 9, Figure 11(b) shows that the light distribution angle θxz in the vertical plane of the vehicle light 10x emitted in the X direction from the light-emitting stud 1 is narrow at 4.5°, and is emitted at a low angle (0.5° to 5°).

In Figure 12(a), the light intensity is 5% or more, in Figure 12(b), the light intensity is 10% or more, and in Figure 12(c), the light intensity in the range of -30° to +30° is 10% or more. This shows that pedestrians can see the pedestrian light 10y from nearby (e.g., around 10 m), nearby (e.g., around 5 m), and immediately nearby (e.g., 0 to 3 m), respectively.

(Effects of the embodiment)
According to this embodiment, the following effects are achieved.
(a) By mounting the light-emitting elements of the vehicle light source 6A at a high mounting density, improving the incidence efficiency of the incident surfaces 30xa and 30xb of the cover lens 3, and forming the exit surfaces 31xa and 31xb as curved surfaces that are convex toward the exit side in a planar view, it is possible to narrow the light distribution angles θxy and θxz of the vehicle light 10x, thereby improving the visibility of the vehicle light 10x from a vehicle driver at a distance (for example, 100 m or more).
(b) By making the optical path length from the incident surfaces 30xa, 30xb to the exit surfaces 31xa, 31xb longer than the optical path length from the incident surfaces 30ya, 30yb to the exit surfaces 31ya, 31yb, the light 10x for vehicles can be emitted to the outside at a lower angle (e.g., 3° to 10°) than the light 10y for pedestrians.
(c) The diffusion function in the vertical plane of the exit surfaces 31ya, 31yb of the cover lens 3, etc., can widen the light distribution angle θyz in the vertical plane of the pedestrian light 10y, thereby improving the visibility of the pedestrian light 10y to pedestrians, including children and adults, who are close to the light-emitting stud 1 (for example, within 10 m).
(d) As shown in installation examples 1 to 3 described below, a vehicle optical system or a pedestrian optical system can be mounted on the substrate 5 depending on the application, thereby improving visibility depending on the application.

(Variation 1)
Fig. 13 is a cross-sectional view corresponding to the cross-sectional view taken along line B-B in Fig. 2 according to Modification 1. In the present embodiment, the condensing lens 7B is used as the light collecting means for collecting the light emitted from the first pedestrian light source 6B, but Modification 1 uses a reflector 7C as an example of the diffusing means.

Reflector 7C is a mirror-type reflector (also called a mirror reflector), and has a body formed, for example, from resin, with a reflective surface 73 made of a metal film (e.g., with a reflectivity of 80%) formed on the surface of the body. Reflective surface 73 is, for example, composed of one or more inwardly concave curved surfaces so that incident light is totally reflected and diffused in a vertical plane.

Figure 14 shows the light intensity distribution in the Y direction for Variation 1. Figure 14(a) shows the light intensity distribution at an elevation angle of 6°, and Figure 14(b) shows the light intensity distribution at an elevation angle of 20°. Figure 14(c) shows the light intensity distribution in the vertical plane. Note that the relative light intensity (%) shown in Figure 14(c) is based on the maximum light intensity (100% in Figure 11(b)) among the light intensities in all directions. Figure 14 also shows the light intensity distribution when only the first pedestrian light source 6B and the second pedestrian light source 6C are used as the light sources 6.

In Figure 14(a), the light intensity is 5% or more, in Figure 14(b), the light intensity is 5% or more, and in Figure 14(c), the light intensity is 20% or more in the ranges of -55° to -20° and +20° to +55°. This shows that pedestrian light 10y can be seen by pedestrians from nearby (e.g., around 10 m), nearby (e.g., around 5 m), and immediately nearby (e.g., 0 to 3 m). In Variation 1, the exit surfaces 31ya and 31yb of cover lens 3 are provided with a diffusion function, and a reflector 7C with a diffusion function is used as the primary lens. However, if a reflector 7C with a diffusion function is used, the exit surfaces 31ya and 31yb of cover lens 3 do not need to be provided with a diffusion function.

(Installation example 1)
15 is a schematic diagram showing installation example 1 of the light-emitting stud according to the present embodiment, with (a) being a plan view and (b) being a side view. In this installation example 1, a plurality of light-emitting studs 1 equipped with only a vehicle optical system are installed on the center line 101 of a road 100. The light-emitting studs 1 of installation example 1 emit light 10x for vehicles in both directions in the X direction along the center line 101. Drivers of vehicles 110A and 110B traveling on the road 100 with the center line 101 as the boundary can see the light 10x for vehicles from a distance (for example, 100 m or more).

(Installation example 2)
16 is a schematic diagram showing installation example 2 of light-emitting studs according to this embodiment, with (a) being a plan view and (b) being a side view. In this installation example 2, a plurality of light-emitting studs 1 equipped with only pedestrian optical systems are installed on a crosswalk 121. The light-emitting studs 1 of installation example 2 emit pedestrian light 10y in both directions in the Y direction along the crossing direction, and emit pedestrian light 10z upward in the Z direction. A pedestrian 130 can easily recognize the position of the crosswalk 121 by the pedestrian lights 10y and 10z.

(Installation example 3)
17 is a diagram schematically illustrating installation example 3 of the luminous studs according to this embodiment. Installation example 3 shown in the figure illustrates two luminous studs 1 installed near an intersection, with one luminous stud 1A installed near the intersection of the outer carriageway line 102 of a wide road 110, and one luminous stud 1B installed near the intersection of a narrow road 110'.

One of the light-emitting studs, 1A, is equipped with one vehicle optical system (vehicle light source 6Ab, condenser lens 7A) and one pedestrian optical system (first pedestrian light source 6Ba, second pedestrian light source 6Ca, reflector 7B, rod lens 8). The other light-emitting stud, 1B, is equipped with only a pair of pedestrian optical systems, as in installation example 2. Pedestrians 130 can recognize that they are approaching an intersection by the pedestrian lights 10y and 10z from light-emitting stud 1B. The vehicle driver can recognize the presence of the outer lane line 102 by the vehicle light 10x from light-emitting stud 1A, and pedestrians 130 can recognize that they are approaching an intersection by the pedestrian lights 10y and 10z from light-emitting stud 1A.

As shown in installation examples 1 to 3 above, by mounting a vehicle optical system or a pedestrian optical system on the substrate 5 depending on the application, visibility can be improved depending on the application.

The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment and various modifications and implementations are possible. For example, in the above embodiment, a condenser lens 7A is used as the light collecting element for the vehicle, but a mirror-type reflector may also be used. Furthermore, in the above embodiment, a vehicle optical system and a pedestrian optical system are used, but it is also possible to use only the second pedestrian light source 6C and rod lens 8 as the pedestrian optical system without using a vehicle optical system. This allows pedestrians in the immediate vicinity (for example, 0 to 3 m) to see the pedestrian light 10z emitted upward in the Z direction.

Furthermore, some of the components of the above embodiment may be omitted or modified. For example, if there is no need to emit upward pedestrian light 10z, the second pedestrian light source 6C and rod lens 8 may be omitted.

1, 1A, 1B...light-emitting rivet, 2...housing, 3...cover lens, 4...case, 5...substrate, 5a...upper surface, 5b...lower surface, 6...light source, 6a...optical axis, 6A, 6Aa, 6Ab...vehicle light source, 6B, 6Ba, 6Bb...first pedestrian light source, 6C, 6Ca, 6Cb...second pedestrian light source, 7A, 7B...condensing lens, 7C...reflector, 8...rod lens, 8a...emitting end surface, 10...light, 10x...light for vehicle, 10y, 10z...light for pedestrian, 10ya...intersection, 11...bolt, 12...mounting surface, 13...packing, 20...lower recess, 21...upper recess, 21a...receiving surface, 21b...screw hole, 21c...packing groove, 22...wall portion, 30...rear protrusion, 30a...Top surface, 30xa, 30xb, 30ya, 30yb...Incidence surface, 31...Top side protrusion, 31a...Top surface, 31xa, 31xb, 31ya, 31yb...Emission surface , 32... Peripheral part, 32a... Receiving surface, 32b... Seat part, 32c... Through hole, 33... Recessed part, 40... Recessed part, 41... Support part, 41a... Upper surface, 60... Multicolor LED, 61... White LED, 70a, 70b...incident surface, 71a, 71b...reflecting surface, 72a, 72b...exiting surface, 73...reflecting surface, 100, 100'...road, 101...center line, 102...outer side line of roadway, 103...stop line, 110, 110A, 110B...vehicle, 120...sidewalk, 121...crosswalk, 130...pedestrian, Hf, Hr...height, _T1 , _T2 ...thickness, θxy, θxz, θyx, θyz, θ'yz...light distribution angle

Claims (4)

a light source disposed at a predetermined position;
a lens element that imparts predetermined light distribution characteristics to light emitted from the light source and emits the light to the outside, the lens element having a back-side protrusion that protrudes in an inverted trapezoidal cross section in a central region of the back side and a front-side protrusion that protrudes in a trapezoidal cross section in a central region of the front side, the lens element being embedded in an installation surface so that the front-side protrusions are exposed to the front side, the side of the back-side protrusion that has the inverted trapezoidal cross section on the side where the light source is arranged being an incident surface with an inclined surface through which light from the light source is incident, and the side of the front-side protrusion that has the trapezoidal cross section on the side opposite to the side where the light source is arranged being an exit surface with an inclined surface that emits the light that has entered the incident surface to the outside,
the light source is configured to be able to be arranged at any one of four predetermined positions in an X direction and a Y direction that are orthogonal to each other in a plan view,
The lens member is formed such that the incident surfaces of the rear-side protrusions are formed in the X direction and the Y direction, respectively, and the exit surfaces of the front-side protrusions are formed in the X direction and the Y direction, respectively, and the optical path length from the incident surface formed in the X direction to the exit surface is longer than the optical path length from the incident surface formed in the Y direction to the exit surface.
Luminous tacks. The lens member is supported by a receiving surface on the periphery of the central region on the rear side, and the receiving surface is located on the front side of the top surface of the rear-side protrusion.
The luminous tack according to claim 1 . the front-side protrusion and the back-side protrusion of the lens member are formed so that a height from a lower base of the inverted trapezoidal cross section to a top surface of the back-side protrusion is greater than a height from a lower base of the trapezoidal cross section of the exit surface to a top surface of the front-side protrusion.
The luminous stud according to claim 1 or 2. a back-side protrusion protruding in an inverted trapezoidal cross section in a central region of the back side, and a front-side protrusion protruding in a trapezoidal cross section in a central region of the front side, wherein a side surface of the inverted trapezoidal cross section of the back-side protrusion serves as an incident surface having an inclined surface on which light is incident, and a side surface of the trapezoidal cross section of the front-side protrusion facing the incident surface serves as an exit surface having an inclined surface from which light incident on the incident surface exits,
the incident surfaces of the rear-side protrusions are formed in the X direction and the Y direction, which are orthogonal to each other in a plan view, and the exit surfaces of the front-side protrusions are formed in the X direction and the Y direction, respectively, such that an optical path length from the incident surface formed in the X direction to the exit surface is longer than an optical path length from the incident surface formed in the Y direction to the exit surface;
Lens components.