JP5241015B2 - Optical lens and road lighting - Google Patents

Description

  The present invention relates to an optical lens used for efficiently illuminating the longitudinal direction of a road, and a road lighting device.

  2. Description of the Related Art Conventionally, there has been known a road lighting device that is attached to a pole erected on a side edge of a road at almost equal intervals to illuminate a road surface. Such road lighting devices include incandescent lamps, fluorescent lamps, street lamps and crime prevention lamps using mercury lamps as light sources, and tunnel lamps that illuminate tunnels using sodium lamps.

  22A and 22B are diagrams showing a conventional street lamp, where FIG. 22A is an external view, and FIG. 22B is a cross-sectional view taken along line A-A ′. The street light 8 has a long and thin cylindrical light source 81 mounted substantially horizontally with respect to a fixture body composed of a reflecting plate 82 and a prism 83. Reflects and refracts to illuminate the road surface.

  Lighting fixtures for roads are often used at an installation interval of about 3 to 4 times the installation height. When the installation interval becomes wider than that, the area directly below the lighting fixture is bright, and the middle of the lighting fixture and the lighting fixture is It becomes dark and the illuminance uniformity in the longitudinal direction of the road decreases.

  In order to solve this problem, there is an example of a road lighting apparatus using a plurality of light emitting diodes (hereinafter abbreviated as “LED”) as a light source and irradiating different directions (for example, Patent Document 1). reference).

  The road lighting device 9 shown in FIG. 23 includes three LEDs 91 to 93 arranged so as to irradiate the directions α, β, and α ′, respectively, and a lens 94 provided in proximity to each of the LEDs 91 to 93. -96. LED91-93 illuminates the range S-U of the road R corresponding to each irradiation direction, as shown in FIG. Thereby, the illuminance uniformity in the longitudinal direction of the road is improved.

  However, according to this example, the number of light sources used in road lighting fixtures increases, resulting in new problems such as an increase in cost due to an increase in the number of parts, an increase in the size of lighting fixtures, and an increase in failure rate. .

JP 2008-210655 A

  The present invention has been made in view of the above circumstances, and provides an optical lens that can efficiently illuminate the longitudinal direction of a road with a single light source, and a compact, low-cost, and highly reliable road lighting apparatus. The purpose is to provide.

  The optical lens of the present invention is an optical lens for diffusing and irradiating light from a single light source to an illumination target, and is a pair of lens units arranged symmetrically opposite to the optical axis of the single light source The lens unit includes an incident surface on which light from the single light source is incident, and an exit surface that radiates the incident light to the outside through a predetermined optical path. A spheroid having a major axis intersecting the optical axis of one light source as a rotation axis is formed from a flat / spheroid surface obtained by flattening the spheroid in a direction perpendicular to the major axis and the minor axis, The flat / spheroid is formed from a surface that protrudes and cuts along a predetermined concave curved surface in a direction perpendicular to the optical axis of the single light source.

  With this configuration, in the road lighting apparatus using a single light source, the longitudinal direction of the road can be illuminated uniformly and efficiently.

  Further, the present invention includes the above optical lens, wherein the facing portion of the lens unit is formed thick.

  With this configuration, when the optical lens is manufactured by resin molding, it is possible to prevent irregularities in shape due to uneven curing and sink marks, and it is possible to provide a highly accurate optical lens at low cost.

  Furthermore, the present invention provides the above-described optical lens, wherein the lens unit is arranged such that the rotation axis has an opening angle of 120 to 180 degrees in the optical axis direction of the single light source. Including those characterized by this.

  With this configuration, in the road lighting apparatus using a single light source, the longitudinal direction of the road can be efficiently illuminated. In addition, it is possible to increase the installation interval of the lighting fixtures for roads, so that resource saving and energy saving can be achieved.

  A road lighting device according to the present invention includes the optical lens described above and a single light source installed at an intersection of major axes of the flat and spheroids.

  With this configuration, it is possible to efficiently illuminate the longitudinal direction of the road while using a single light source, and it is possible to provide a small, low-cost, and highly reliable road lighting device.

  In addition, the present invention includes the above-described road luminaire including an inverted V-shaped reflector on the optical axis of the single light source.

  With this configuration, it is possible to increase the illuminance uniformity on the road surface in the vicinity immediately below the road lighting device and in the distance in the longitudinal direction.

  Furthermore, the present invention is characterized in that, in the above-mentioned road lighting apparatus, the single light source is a light emitting diode.

  With this configuration, it is possible to provide a compact, low-cost, and highly reliable road lighting device.

  The optical lens of the present invention is an optical lens for diffusing and irradiating light from a single light source to an illumination target, and is a pair of lens units arranged symmetrically opposite to the optical axis of the single light source The lens unit includes an incident surface on which light from the single light source is incident, and an exit surface that radiates the incident light to the outside through a predetermined optical path. An even-order curve body having an axis intersecting with the optical axis of one light source as a rotation axis is formed from a flat and rotated even-order curve body surface of an even-order curve obtained by flattening in the optical axis direction of the single light source. It is characterized by.

  With this configuration, in the road lighting apparatus using a single light source, the longitudinal direction of the road can be efficiently illuminated.

  ADVANTAGE OF THE INVENTION According to this invention, the optical lens which can illuminate the longitudinal direction of a road efficiently with a single light source, and a small and low-cost and highly reliable road lighting fixture can be provided.

The perspective view which shows the external appearance of the optical lens which concerns on Embodiment 1 of this invention. The perspective view which shows the external appearance of the flat and a spheroid used as the basic form of the optical lens which concerns on Embodiment 1 of this invention. FIG. 3 is a projection view showing a flat and spheroid as a basic shape of the optical lens according to Embodiment 1 of the present invention by the third angle method. The perspective view which shows the external appearance of the cutting | disconnection / flattening / spheroid of the optical lens which concerns on Embodiment 1 of this invention FIG. 3 is a projection view showing the cutting, flattening, and spheroid of the optical lens according to Embodiment 1 of the present invention by the third angle method. Sectional drawing which shows schematic structure of the lighting fixture for roads which concerns on Embodiment 1 of this invention The schematic diagram for demonstrating the illumination direction at the time of installing the lighting fixture for roads concerning Embodiment 1 of this invention The perspective view which shows the external appearance of the optical lens which concerns on Embodiment 2 of this invention. Sectional drawing which shows schematic structure of the lighting fixture for roads concerning Embodiment 2 of this invention Sectional drawing which shows schematic structure of the optical lens which has the planar entrance plane in Embodiment 2 which concerns on this invention. Sectional drawing which shows schematic structure of the optical lens whose incident surface is convex shape in Embodiment 2 which concerns on this invention. Sectional drawing which shows schematic structure of the lighting fixture for roads provided with the optical lens which formed the draft for the shaping | molding in the output surface in Embodiment 2 which concerns on this invention Sectional drawing which shows schematic structure of the optical lens which has a flange in Embodiment 2 which concerns on this invention. Sectional drawing which shows schematic structure of the optical lens which consists of a flat and rotation hyperboloid in which Embodiment 2 which concerns on this invention has the same curvature as an output surface in a flat and a spheroid (A) The optical lens which concerns on Embodiment 2 of this invention WHEREIN: The figure which shows the optical path in the short axis direction OO 'cross section of a flat and a spheroid (b) In the optical lens which concerns on Embodiment 2 of this invention FIG. 4C is a diagram showing an optical path in the short axis direction BB ′ cross section of the flat / spheroid (c) In the optical lens according to Embodiment 2 of the present invention, the short axis direction EE ′ cross section of the flat / spheroid Showing the optical path in Sectional drawing which shows schematic structure of the lighting fixture for roads which concerns on Embodiment 3 of this invention. Projection diagram showing shape of optical lens according to Embodiment 3 of the present invention by the third angle method The figure which shows the light distribution characteristic of the optical lens which concerns on Embodiment 3 of this invention. Sectional drawing which shows schematic structure of the lighting fixture for roads which concerns on Embodiment 4 of this invention. The figure for demonstrating an effect | action when there is no reflecting plate in the road lighting fixture which concerns on Embodiment 4 of this invention. In the lighting fixture which concerns on Embodiment 4 of this invention, the perspective view which shows schematic structure of a modification. (A) The perspective view which shows the external appearance of the conventional road lighting fixture (b) Sectional drawing which shows schematic structure of the conventional road lighting fixture Sectional drawing which shows schematic structure of the conventional lighting fixture for roads which uses LED for a light source Schematic diagram for explaining the lighting direction when a conventional lighting fixture is installed on the road

  DESCRIPTION OF EMBODIMENTS Hereinafter, an optical lens and a road lighting device according to an embodiment of the present invention will be described with reference to the drawings. The optical lens according to the embodiment of the present invention can use a material that is transparent to the radiation spectrum of light emitted from a light source, such as acrylic resin, polycarbonate resin, silicon resin, polyolefin resin, and glass.

(Embodiment 1)
FIG. 1 is a perspective view showing an appearance of an optical lens according to Embodiment 1 of the present invention. As shown in the figure, the optical lens 10 of the present embodiment has a light incident surface 101 formed in a bowl shape and a light emission surface 102 formed from a flat / spheroid surface, which will be described later. It is comprised from a pair of lens units 10a and 10a of the same shape arrange | positioned symmetrically with respect to the optical axis of the light source.

  The lens unit 10a constituting the optical lens 10 is designed as described below.

  FIG. 2 is a perspective view showing an appearance of a flat / spheroid that is a basic shape of the lens unit 10a, and FIG. 3 is a projection view showing the flat / spheroid by the third angle method.

  As shown in FIGS. 2 and 3, the flat / spheroid 10b has a shape obtained by flattening the rotating body obtained by using the long axis X of the ellipse composed of the long axis X and the short axis Y as the rotation axis to a height Z. is there.

  Next, the flat / spheroid 10b obtained in this manner is projected and cut in a direction parallel to the short axis Y with a predetermined concave curved surface. FIG. 4 is a perspective view showing the appearance of the cut / flat / spheroid obtained in this manner, and FIG. 5 is a projection view showing the cut / flat / spheroid 10c by the third angle method.

  4 and 5, the cut and flattened / spheroid 10c protruding surface is an incident surface 101 on which light is incident, and the other surface is an output surface 102 that diffuses light and emits it to the outside.

  Next, as shown in FIG. 5, the cut / flat / spheroid 10 c is cut along a G-G ′ plane parallel to the minor axis Y. The cutting / flattening / spheroid formed in this way is the lens unit 10a, and two of them are arranged facing each other so as to be in close contact with the GG ′ plane, whereby the optical shown in FIG. A lens 10 is obtained.

  FIG. 6 is a cross-sectional view showing a schematic configuration of the road lighting apparatus according to Embodiment 1 of the present invention. In the figure, this road lighting device 1 has an optical lens 10 and an LED 50.

  Since the optical lens 10 has only one light emitted from the LED 50, a portion above the broken line H-H 'where no light is incident is cut into a flat shape. Thereby, the optical lens 10 itself is reduced in size and weight.

  Further, symbols OO ′ and PP ′ in the optical lens 10 indicate the major axis X of the flat / spheroid that is the basic shape of each of the two lens units 10a and 11, and the LED 50 is a line segment. It is installed at the intersection of each extension line of OO ′ and PP ′.

  Next, the function of the optical lens 10 according to Embodiment 1 of the present invention will be described with reference to FIG.

  The light emitted from the LED 50 and incident between the locations A to B on the incident surface 101 has a convex lens shape in the section surrounded by A, A ′, B, and B ′ in the cross section, and therefore the arrow α It is condensed in the direction of the extension line of the line segment OO ′ indicated by. The direction indicated by the arrow α ′ is symmetric with the direction indicated by the arrow α with respect to the optical axis of the LED 50, and the light emitted from the LED 50 is the direction of the extension line of the line segment PP ′ indicated by the arrow α ′. In the same way, the light is condensed.

  On the other hand, the light incident between the locations C to D of the incident surface 101 has a concave lens in the portions surrounded by C, C ′, D, and D ′. Diffused.

  Accordingly, when the road lighting device 1 of the present embodiment is installed on the road R as shown in FIG. 7, the α and α ′ directions are far from the longitudinal direction of the road, for example, the areas of S and S ′. Each of the lights is illuminated, and the diffused light is applied to the region of the road surface T in the direction of β, which is directly below the road lighting device 1. In addition, although the light is diffused on the road surface immediately below the lighting fixture 1 for roads, the illuminance is ensured because the irradiation distance is short. Therefore, a wide range in the longitudinal direction of the road can be efficiently illuminated by one LED light source.

(Embodiment 2)
FIG. 8 is a perspective view showing the appearance of the optical lens according to Embodiment 2 of the present invention. As shown in the figure, the optical lens 20 of the present embodiment has a light incident surface 201 formed in a bowl shape and a light emission surface 202 formed from a flat / spheroid surface, which will be described later. It is comprised from a pair of lens unit 20a, 20a of the same shape arrange | positioned symmetrically with respect to the optical axis of the light source.

  The lens unit 20a is composed of a cutting / flattening / spheroid 10c as in the first embodiment. The optical lens 20 of the present embodiment is different from the optical lens 10 of the first embodiment in that the opposing portions of the pair of lens units 20a and 20a are formed thick.

  In this way, by forming the opposing portions of the pair of lens units 20a and 20a thick, the light distribution continuity at the opposing portions becomes better than that of the optical lens 10 of the first embodiment.

  In addition, when the optical lens 20 is manufactured by resin molding, it is possible to avoid uneven curing caused by temperature distribution during cooling, and a design shape and manufacturing caused by unevenness in refractive index and sink due to resin curing. A shape shift or the like can be prevented, and the optical lens 20 can be manufactured with high accuracy.

  FIG. 9 is a cross-sectional view showing a schematic configuration of a road lighting apparatus according to Embodiment 2 of the present invention. In the figure, the road lighting device 2 has a configuration having an optical lens 20 and an LED 50. In addition, about the structure similar to FIG. 6 in Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted or abbreviate | omitted.

  Since the optical lens 20 emits only one light from the LED 50, the portion where the light is not incident is cut into a flat shape as in the first embodiment. Thereby, the optical lens 20 is reduced in size and weight.

  The optical lens 20 has a light incident surface 201 protruding and formed in a bowl shape. However, the present invention is not limited to this. For example, as shown in FIG. 10, the optical lens 20 may be formed on a flat incident surface 203. Good. Moreover, as shown in FIG. 11, it can also be formed on the incident surface 204 having a convex shape.

  Furthermore, as shown in FIG. 12, it is good also as a shape which improved the workability by deform | transforming the V part of a flat and a spheroid surface, tapering, and making it the draft in the case of resin molding. According to this, as indicated by the line segment A′-A ″, the direction of the light is slightly shifted upward in the α direction, but the light emitted from the LED 50 is directional and the luminance in the A direction is small. Therefore, the effect on lighting is negligible.

  Moreover, as shown in FIG. 13, you may make it the shape which extended the upper plane part to right and left, and formed the flange 205. FIG. The flange 205 is provided with a mounting hole 206 formed of a round hole or a U-shaped notch, and is used for mounting the optical lens 24 to the lighting fixture body.

  FIG. 14 is a cross-sectional view showing an optical lens 30 formed by flattening a hyperbolic rotator having the same curvature on the exit surface, instead of the basic shape of the optical lens 20 being a flat / spheroid 10b. In this way, if the curvature of the exit surface is the same as that of the flat / spheroid 10a, it is not limited to a hyperbola and can be a higher order even degree curve such as a quadratic curve or a quartic curve such as a parabola. It is also possible to do.

  Next, the function of the optical lens 20 according to Embodiment 2 of the present invention will be described with reference to FIG.

  The light emitted from the LED 50 and incident between the portions A to B on the incident surface 201 has a convex lens shape in the section surrounded by A, A ′, B, and B ′ in the cross section. It is condensed in the direction of the extension line of the line segment OO ′ indicated by. The direction indicated by the arrow α ′ is symmetric with the direction indicated by the arrow α with respect to the optical axis of the LED 50, and the light emitted from the LED 50 is the direction of the extension line of the line segment PP ′ indicated by the arrow α ′. In the same way, the light is condensed.

  On the other hand, the light incident between the locations E to D of the incident surface 201 has a concave lens shape in the portions surrounded by E, E ′, F, and F ′. Slightly spread and diffused slowly.

  FIGS. 15A to 15C show optical paths in the cross-sections of OO ′, BB ′, and EE ′ in the minor axis Y direction of the flat and spheroid 10 b constituting the optical lens 20. FIG. Note that the A-A ′ cross section is symmetrical to the B-B ′ cross section with respect to the line segment O-O ′, and the optical path is the same, so the illustration is omitted.

  Referring to FIGS. 15A to 15C, the radius of curvature of the exit surface 202 increases from the OO ′ cross section toward the EE ′ cross section. It can also be seen that light is collected in this cross section. Note that it is the short axis Y of the flat / spheroid ellipsoid 10b, which is the basic shape, that determines the radius of curvature of the exit surface 202. If this short axis Y is increased, the light is condensed in the cross section AA ′ to EE ′. Sex declines.

  From this, the illumination width in the road width direction of the road lighting device 2 when installed on the road is widened. Therefore, the optical lens 20 needs to design the short axis Y of the flat / spheroid 10b according to the width of the road on which the road lighting device 2 is installed.

  From the above, when the road lighting device 1 of the present embodiment is installed on the road R as shown in FIG. 7, the α and α ′ directions are far from the longitudinal direction of the road, for example, the areas of S and S ′. Each of the lights is illuminated, and the diffused light is applied to the region of the road surface T in the direction of β, which is directly below the road lighting device 1.

  In addition, the illuminance tends to be high because the distance to the road that is the irradiation surface is short in the β direction, but as shown in FIG. 9, the light in the β direction diffuses in the longitudinal direction of the road. The illuminance in the vicinity immediately below the luminaire 2 is suppressed, and as a result, the illuminance uniformity on the road surface in the longitudinal direction extending from the vicinity of the road luminaire 2 to the distance can be increased.

(Embodiment 3)
As shown in FIG. 23, in the conventional road lighting device 9 using a single light source, the opening angle in the α and α ′ directions is limited to about 120 °. Usually, the installation interval of road lighting equipment is often used at about 3 to 4 times the installation height, and the practical range even for road lighting equipment with an opening angle of about 80 to 120 ° in the α and α ′ directions. The road surface illuminance uniformity can be secured.

  However, from the viewpoint of resource saving and energy saving, it is desired to further increase the mounting interval of the road lighting fixtures. Also, in lighting fixtures such as security lights, the installation interval is often more than four times the installation height, and some of them do not satisfy the recommended illuminance standards set by the Japan Security Equipment Association. Often there is a lack of spread. The road lighting apparatus according to Embodiment 3 of the present invention addresses these problems.

  FIG. 16: is sectional drawing which shows schematic structure of the lighting fixture for roads which concerns on Embodiment 3 of this invention. In FIG. 16, the road lighting device 3 includes an optical lens 40 and an LED 50.

  The optical lens 40 is configured such that the opening angle θ of the line segments OO ′ and PP ′ on the major axis of the flat and spheroid 10b constituting the opposing lens units is 120 to 180 °. ing.

  FIG. 17 is a projection view showing the optical lens according to Embodiment 3 of the present invention by the third angle method. In the figure, the optical lens 40 has a ratio of the major axis X, minor axis Y, and flat height Z of the flat / spheroid 10b, which is the basic shape, of 1.56: 1.21: 1. The opening angle is 180 °.

  FIG. 18 is a diagram illustrating the light distribution characteristics of the optical lens 40. In the figure, the solid line shows the light distribution characteristic in the longitudinal direction of the road, and the broken line shows the light distribution characteristic in the road width direction.

  Referring to FIG. 18, it can be seen that the road illumination fixture 3 configured using the optical lens 40 can irradiate uniform illumination light farther in the longitudinal direction of the road.

(Embodiment 4)
FIG. 19 is a cross-sectional view showing a schematic configuration of a road lighting apparatus according to Embodiment 4 of the present invention. The road lighting device 4 according to the present embodiment has a configuration including the optical lens 40, the LED 50, and the reflection plate 60 according to the third embodiment.

  The reflection plate 60 is narrower than the light emitting portion of the LED 50 and is formed in an inverted V shape, and is installed immediately below the LED 50. As a result, the light emitted from the LED 50 is reflected by the reflecting plate 60 and then reaches a long distance in the longitudinal direction of the road via the optical path I-I ′.

  On the other hand, a part of the light emitted from the LED 50 in the vertical direction is blocked by the reflector 60. However, since the reflecting plate 60 is narrower than the light emitting portion of the LED 50, the light leaked from the side illuminates the vicinity immediately below the road lighting device 4 through the optical path J-J '.

  When the installation interval of the road lighting device 4 is large, the optical path of the illumination light becomes very long in the longitudinal direction of the road. Therefore, even if a part of the light leaks from the side of the reflector 60, the illuminance is not insufficient only in the vicinity immediately below the road lighting device 4 as compared with the illuminance far in the longitudinal direction of the road.

  FIG. 20 is a diagram showing a schematic configuration of the road lighting device 5 when the reflector 60 is not provided in FIG. In FIG. 20, when the incident surface 401 of the optical lens 40 is perpendicular to the LED 50, the refracted light can be emitted toward the far side in the longitudinal direction of the road, but if the angle γ of the incident surface 401 becomes smaller, Since the normal line of the LED 50 and the angle of the incident surface 401 are nearly parallel, the light flux incident from the LED 50 is reduced, and the required illuminance cannot be ensured far away in the longitudinal direction of the road.

  FIG. 21 is a perspective view showing the road lighting device 6 configured by providing a pair of side reflectors 70 in a space forming the incident surface of the optical lens 40.

  In FIG. 21, the side reflectors 70 and 70 are installed facing each other in the minor axis direction of the flat / spheroid. Thereby, glare can be prevented. When the side reflectors 70 and 70 are installed for the purpose of eliminating only glare, a surface treatment that has both light shielding properties and light absorption properties is applied. The illuminance in the vicinity immediately below the luminaire 6 is only slightly increased, and the illuminance distribution on the entire road surface is not greatly changed. Accordingly, the side reflector 70 may be a surface treatment such as white reflective coating.

  As described above, according to such a lighting apparatus according to Embodiment 4 of the present invention, it is possible to secure the necessary illuminance to the far side in the longitudinal direction of the road even if the installation interval is further expanded, and the road It is possible to avoid a shortage of vertical surface illuminance in the immediate vicinity of the lighting equipment for lighting, which is effective for a security light that needs to identify the face of a pedestrian.

1, 2, 3, 4, 6 Road lighting apparatus 10, 20, 30, 40 Optical lens 10a, 20a Lens unit 10b Flat / spheroid 10c Cutting / flat / spheroid 101, 201, 203, 204, 301 401, incident surface 102, 202, exit surface 50 LED
60 reflector 70 side reflector

Claims (7)

An optical lens for diffusing and irradiating light from a single light source to an illumination target,
Formed from a pair of lens units disposed symmetrically opposite the optical axis of the single light source,
The lens unit is
An incident surface on which the light of the single light source is incident, and an emission surface that radiates the incident light to the outside through a predetermined optical path,
The exit surface is
A spheroid having a major axis intersecting the optical axis of the single light source as a rotation axis is formed from a flat and spheroid surface obtained by flattening in a direction perpendicular to the major axis and the minor axis,
The incident surface is
The flat / spheroid is formed from a surface that protrudes and cuts with a predetermined concave curved surface in a direction perpendicular to the optical axis of the single light source,
An optical lens characterized by the above. The optical lens according to claim 1,
The facing portion of the lens unit is formed thick.
An optical lens characterized by the above. The optical lens according to claim 1 or 2,
The lens unit is
The rotation axis is arranged with an opening angle of 120 to 180 degrees in the optical axis direction of the single light source.
An optical lens characterized by the above. An optical lens according to any one of claims 1 to 3,
A single light source installed at the intersection of the long axis of the flat and spheroid,
Comprising
A lighting device for roads characterized by that. The road lighting device according to claim 4,
Provided with an inverted V-shaped reflector on the optical axis of the single light source,
A lighting device for roads characterized by that. The road lighting device according to claim 4 or 5,
The single light source is
A light emitting diode,
A lighting device for roads characterized by that. An optical lens for diffusing and irradiating light from a single light source to an illumination target,
Formed from a pair of lens units disposed symmetrically opposite the optical axis of the single light source,
The lens unit is
An incident surface on which the light of the single light source is incident, and an emission surface that radiates the incident light to the outside through a predetermined optical path,
The exit surface is
An even-order curve body having an axis that intersects the optical axis of the single light source as a rotation axis is formed from a flat and rotated even-order curve body surface of an even-order curve obtained by flattening in the optical axis direction of the single light source. An optical lens.