JP2002042523A - Light irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light irradiation device which is thin while a radiation cross section of light (luminous area) is larger. SOLUTION: A thin reflective mirror 11 comprising a parabolic, in cross section, reflective surface 11a is sandwiched between an upper plate 14 and a lower plate 15, and an LED 12 is provided at a focal point of the parabola of the reflective surface 11a, being at the central part in thickness direction of the thin reflective mirror 11. The LED 12 is narrow angle light distribution type where a radiation angle range of light is narrow, its radiating direction of light is directed around the central part of the reflective surface 11a. A cylindrical concave lens 13 is provided in front of, close to, the LED 12. The cylindrical concave lens 13 is so arranged that its axial direction of the concave surface matches the thickness direction of the thin reflective mirror 11. The light emitted from the LED 12 is expanded with the cylindrical concave lens 13 at an XY plane vertical to the thickness direction of the thin reflective mirror 11, and is reflected on almost the entire reflective surface 11a to become a wide parallel beam in X direction, outgoing in Y direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device which is installed on a center line of a road, an intersection, a road surface of a crosswalk, etc. and emits light for guidance and warning, and more particularly to a self-luminous road tack.

[0002]

2. Description of the Related Art A light irradiating apparatus of this type includes a light emitting diode (LED) and a driving circuit (power supply circuit) thereof, and emits light at night to warn or guide a driver or a pedestrian of a vehicle. It is installed for the purpose of performing. It is usually installed on the road surface, such as the center line of a road, the center of an intersection, or a pedestrian crossing, and emits light in a range where the elevation angle from the road surface is relatively small.

In addition, it is used on a road surface or a wall surface in a tunnel for the purpose of specifying the curved shape and lane width of the tunnel. It is installed in underground malls and public spaces, and is used as a landmark at night or as an emergency evacuation guidance sign.

FIG. 15 is a cross-sectional side view showing a schematic structure of a self-luminous road tack as a conventional light irradiation device. Road surface 1
01, a casing 102 having a trapezoidal cross section protrudes, and light emitting windows are provided at a predetermined pitch on inclined surfaces 102a on both sides thereof. The LEDs 103 mounted on the substrate 104 are arranged inside each light emitting window. These LEDs 10
Reference numeral 3 is driven by a drive circuit (not shown) and emits predetermined light. This light is applied to the inclined surface 10 of the casing 102.
The light exits from the light emitting window provided in 2a and is visually recognized by a pedestrian or a vehicle driver.

[0005]

One of the drawbacks of the above-mentioned conventional light irradiation device (self-luminous road stud) is that its structure is
The projecting height from the road surface 101 increases, and depending on the installation location, it may be an obstacle for pedestrians and vehicles. Incidentally, the projecting height of the conventional self-luminous road stud (casing 102) was 20 to 30 mm.

Further, since the light emitted from the relatively small LED 103 is directly emitted from the light emitting window of the inclined surface 102a of the casing 102, there is a problem that the light emission cross section is small and visibility is poor.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a light irradiating apparatus which is thin and can increase the light emission cross section (light emitting area).

[0008]

As shown in FIG. 1, a light irradiating apparatus according to the present invention comprises a reflecting mirror 11 having a reflecting surface 11a formed by cutting out a part of a paraboloid, An LED light source 12 disposed at or near the focal point, and a lens 13 disposed between the reflection surface 11a and the LED light source 12 and irradiating substantially the entire reflection surface 11a. .

According to this configuration, the light emitted from the LED light source 12 is controlled by the lens 13 and is reflected by substantially the entire reflecting surface 11a to become substantially parallel light. That is, the light is effectively used, and the emission cross section (light emission area) can be increased.

As a specific first configuration, as shown in FIG. 2, the reflecting mirror 11 is a thin reflecting mirror having a reflecting surface 11a having a parabolic cross section, and the LED light source 12 is a narrow-angle light distribution type LED. The lens 13 is a cylindrical concave lens, and the thickness direction (Z-axis direction) of the thin reflecting mirror 11 and the concave axis direction (A) of the cylindrical concave lens 13 match (all in the Z direction).

According to this configuration, the narrow-angle light distribution type LED 12
Although the light emitted from does not spread in the Z direction, it is spread in the direction of the XY plane, and is reflected by substantially the entire reflecting surface 11a to become substantially parallel light. That is, it is possible to increase the emission cross section (light emission area) in the direction of the XY plane while suppressing light diffusion loss in the thickness direction (Z-axis direction) of the thin reflecting mirror 11.

As a specific second configuration, as shown in FIG. 3, the reflecting mirror 11 is a thin reflecting mirror having a reflecting surface 11a having a parabolic cross section, and the LED light source 12 is a wide-angle light distribution type LED. The lens 13 is a cylindrical convex lens, and the thickness direction (Z-axis direction) of the thin reflecting mirror 11 and the convex axial direction (A, that is, the direction of the XY plane) of the cylindrical convex lens 13 are orthogonal to each other.

According to this configuration, the wide-angle light distribution type LED 12
The light that has exited in the direction of the XY plane proceeds as it is, and is reflected by substantially the entire reflecting surface 11a to become substantially parallel light. In the Z direction, the light is collected by the cylindrical convex lens 13. Therefore, also in this case, it is possible to increase the emission cross section (light emission area) in the direction of the XY plane while suppressing the light diffusion loss in the thickness direction (Z-axis direction) of the thin reflecting mirror 11.

As a specific third configuration, as shown in FIG. 4, a thin reflecting mirror 11 having a reflecting surface 11a having a parabolic cross section and a thickness direction of the thin reflecting mirror 11 at or near the focal point of the parabola. LED light source 1 arranged substantially at the center
Wherein the lens of the LED light source 12 has a narrow-angle light distribution characteristic in the thickness direction (Z-axis direction) of the thin reflecting mirror 11 and a direction (XY) perpendicular to the thickness direction of the thin reflecting mirror 11.
(In the direction of a plane). LE like this
The D lens shape is called an anamorphic lens, and the cross-sectional shape in the Z-axis direction and the cross-sectional shape in the XY plane direction are different shapes, each having a spherical or aspherical lens cross-sectional shape. Also in this case, the thickness direction (Z
The emission cross section (light emission area) can be increased in the direction of the XY plane while suppressing the diffusion loss of light in the (axial direction).

The light irradiating device having each of the above structures is preferably used for a self-luminous road stud installed on a road surface such as a center line of a road, an intersection, or a crosswalk.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 is an exploded view of the light irradiation device according to the embodiment of the present invention. FIGS. 6A and 6B are views showing the internal structure of the light irradiation device according to the first embodiment of the present invention in plan view and side view. In addition,
In the drawings referred to in the present embodiment and other embodiments,
Components having the same function are given the same numbers.

A thin reflecting mirror 11 having a reflecting surface 11a having a parabolic cross section is sandwiched between an upper plate 14 and a lower plate 15, and the reflecting surface 1
The LED 12 is arranged at the center of the thickness direction of the thin reflecting mirror 11 at the focal point of the parabola 1a. The LED 12 is a narrow-angle light distribution type in which the angle of light emission range (emission angle range) is narrow, and the light emission direction is directed to a substantially central portion of the reflection surface 11a.

A cylindrical concave lens 13 is arranged in front of the LED 12 (in the light emission direction). The cylindrical concave lens 13 is arranged such that the concave axis direction coincides with the thickness direction of the thin reflecting mirror 11. That is, the light emitted from the LED 12 is reflected by the thin reflecting mirror 1.
In the thickness direction 1 (Z-axis direction), even though the light passes through the cylindrical concave lens 13, there is almost no refraction effect, but in the direction perpendicular to the thickness direction (XY plane), it is expanded by the cylindrical concave lens 13. As a result, the reflection surface 11a
Is reflected by substantially the entire area of the light beam and becomes a wide parallel light beam in the X direction.
Emit in the direction. That is, it is possible to obtain a light irradiating device having a large light emitting section in the X direction and high visibility while suppressing leakage loss due to diffusion in the Z axis direction.

FIG. 7 shows the external dimensions of the light irradiation device in one example of this embodiment. FIG. 8 shows parameters of a parabola which is a cross-sectional shape of the reflecting surface 11a of the thin reflecting mirror 11. FIG. 9 shows the external dimensions of the cylindrical concave lens 13 and the distance from the LED 12.

FIGS. 10A and 10B show a second embodiment of the present invention.
It is a figure which shows the internal structure in planar view and side view of the light irradiation apparatus which concerns on embodiment. The light irradiation device according to the present embodiment has L
The ED 12 is different from the first embodiment in that the ED 12 is a wide-angle light distribution type having a wide light emission angle range and the lens 13 is a cylindrical convex lens. The convex axis direction (direction of the XY plane) of the cylindrical convex lens is orthogonal to the thickness direction (Z-axis direction) of the thin reflecting mirror 11.

Therefore, the light emitted from the LED 12 is
In the thickness direction (Z-axis direction) of the thin reflecting mirror 11, the light is collected by the cylindrical convex lens 13, and in the direction perpendicular to the thickness direction (XY plane), the reflection surface of the thin reflecting mirror 11 remains wide and unaffected by the cylindrical convex lens 13. Reaches 11a. As a result, the light is reflected by substantially the entire reflecting surface 11a, becomes parallel light rays wide in the X direction, and is emitted in the Y direction. That is, similarly to the first embodiment, a light irradiation device having a large light emission cross section in the X direction and high visibility can be obtained while suppressing leakage loss due to diffusion in the Z axis direction.

FIG. 11 shows the distance between the external dimensions of the cylindrical convex lens 13 and the LED 12 in one example of this embodiment. The outer dimensions of the light irradiation device and the parameters of the parabola of the reflecting surface 11a of the thin reflecting mirror 11 are the same as those in the first embodiment, and are as shown in FIGS.

FIGS. 12A and 12B show a third embodiment of the present invention.
It is a figure which shows the internal structure in planar view and side view of the light irradiation apparatus which concerns on embodiment. The light irradiation device according to the present embodiment has L
The point that the ED 12 has an anamorphic lens having different light distribution characteristics between the XY plane and the XZ plane is different from the above-described embodiment. That is, as shown in FIG. 13, the XY plane has a wide-angle light distribution characteristic, and the XZ plane has a narrow-angle light distribution characteristic. Thereby, the cylindrical lens 13 used in the above-described embodiment becomes unnecessary.

FIG. 14 shows the LED 12 used in one embodiment.
FIG. 3 is a diagram showing the shape of the anamorphic lens of FIG. The anamorphic lens has different lens shapes in the vertical section on the XY plane and the vertical section on the XZ plane. Here, R in the vertical section on the XY plane is large, and R in the vertical section on the XZ plane is small. This makes it possible to obtain a narrow-angle light distribution characteristic in the Z direction and a wide-angle light distribution characteristic in the XY plane without using a separate cylindrical lens. As a result, similar to the above-described embodiment,
In the Z-axis direction, a light irradiation device having a large light emission cross section in the X direction and high visibility can be obtained while suppressing leakage loss due to diffusion.

As described above, the light irradiation device of the present invention has been described according to various embodiments. However, the present invention is not limited to the above embodiment, and may be embodied in other forms.

[0026]

As described above, according to the light irradiation apparatus of the present invention, while being thin in the Z-axis direction and suppressing leakage loss due to diffusion, parallel light having a large cross section in the X direction and high visibility can be obtained. Light can be emitted in the Y direction.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining a configuration of a light irradiation device of the present invention.

FIG. 2 is a side view for explaining a first specific configuration of the light irradiation device of the present invention.

FIG. 3 is a side view for explaining a second specific configuration of the light irradiation device of the present invention.

FIG. 4 is a side view for explaining a third specific configuration of the light irradiation device of the present invention.

FIG. 5 is an exploded view of the light irradiation device according to the embodiment of the present invention.

FIG. 6 is a diagram showing an internal structure of the light irradiation device according to the first embodiment of the present invention in a plan view and a side view.

FIG. 7 is a diagram showing external dimensions of a light irradiation device in one embodiment.

FIG. 8 is a diagram showing parameters of a parabola which is a cross-sectional shape of a reflection surface of a thin reflecting mirror.

FIG. 9 is a diagram showing an outer dimension of a cylindrical concave lens and a distance from an LED.

FIG. 10 is a diagram showing an internal structure of a light irradiation device according to a second embodiment of the present invention in plan view and side view.

FIG. 11 is a diagram showing an outer dimension of a cylindrical convex lens and a distance from an LED in one embodiment.

FIG. 12 is a diagram showing an internal structure of a light irradiation device according to a third embodiment of the present invention in plan view and side view.

FIG. 13 is a diagram showing light distribution characteristics of an LED.

FIG. 14 is a diagram showing a shape of an anamorphic lens of an LED used in one example.

FIG. 15 is a side view sectional view showing a schematic structure of a self-luminous road tack as a conventional light irradiation device.

[Explanation of symbols]

 Reference Signs List 11 Reflecting mirror 11a Reflecting surface 12 LED light source 13 Lens Y Light emitting direction Z Thickness direction of thin reflecting mirror

Claims (5)

[Claims] 1. A reflecting mirror having a reflecting surface having a shape obtained by cutting out a part of a paraboloid, an LED light source disposed at or near a focal point of the paraboloid, and the reflecting surface and the LED light source. A light irradiating device comprising: a lens disposed between the lenses to irradiate substantially the entire reflecting surface with light emitted from the LED light source. 2. The reflector according to claim 1, wherein the reflector is a thin reflector having a parabolic reflective surface, and the LED light source is a narrow-angle light distribution type L.
2. The light irradiation device according to claim 1, wherein the light emitting device is an ED, wherein the lens is a cylindrical concave lens, and a thickness direction of the thin reflecting mirror coincides with a concave axial direction of the cylindrical concave lens. 3. The reflecting mirror is a thin reflecting mirror having a parabolic reflecting surface in cross section, and the LED light source is a wide-angle light distribution type L.
2. The light irradiation device according to claim 1, wherein the lens is an ED, and the lens is a cylindrical convex lens, and a thickness direction of the thin reflecting mirror is orthogonal to a convex axis direction of the cylindrical convex lens. 4. An LED light source comprising: a thin reflecting mirror having a reflecting surface having a parabolic cross section; and an LED light source disposed at or near a focal point of the parabola at a substantially central portion in a thickness direction of the thin reflecting mirror. A light irradiating device, wherein the lens has a narrow-angle light distribution characteristic in a thickness direction of the thin reflecting mirror and a wide-angle light distribution characteristic in a direction perpendicular to the thickness direction of the thin reflecting mirror. 5. The light irradiation device according to claim 1, wherein the light irradiation device is used for a self-luminous road stud installed on a road surface such as a center line of a road, an intersection, and a pedestrian crossing.