DE102010046082B4 - street lamp - Google Patents

Abstract

A street lamp (100; 200) comprising a refractive screen (6) having a focal length f formed as a linear Fresnel condenser lens, the refraction screen (6) comprising a plurality of steps (18) spaced at a mutual distance in the range of about 0.4 mm to about 0.8 mm, at least a first illumination unit (4), which is arranged substantially between a vertical axis (VA) of the street lamp (100; 200) and the refractive screen (6), wherein the first illumination unit (4) a A plurality of first light sources (2) and is adapted to emit light such that at least about 50% of the radiated light power within a vertical Abstrahlöffnungswinkels (14) from about 60 ° to about 100 °, which by a first angle of attack (16) of first illumination unit (4) is centered relative to the vertical axis (VA), wherein the first angle of attack (16) is in a range of about 65 ° to about 85 °, wherein at least a first Lich the source of the first illumination unit (4) is arranged at a distance from the refraction shield (6) which substantially corresponds to the focal length f of the refraction shield (6); and at least one second illumination unit (20) having a plurality of second light sources (22) and adapted to emit light such that at least about 50% of the radiated light power is within a vertical emission angle of about 60 ° to about 100 ° is centered about a second angle of incidence (24) of the second illumination unit (20) relative to the vertical axis (VA), wherein the second angle of attack (24) is in a range of about 15 ° to about 45 °.

Description

The present invention relates to a street lamp and a use of a street lamp.

Hereinafter, the term street lamp, for example, lighting systems or arrangements for roads, walkways, pedestrian areas, parking areas and parks to understand. The street lamps include in particular so-called mushroom and pole lights.

The publication US 6,502,964 B1 discloses a lamp for homogeneous illumination of architectural surfaces. The lamp has a point light source disposed vertically near an architectural surface and a multi-zone refractory screen surrounding the light source. The refractor screen may be a Fresnel lens.

The publication GB 774,753 A discloses a street lamp comprising an elongate cylindrical light source and a refractor screen having cylindrically-convex lenses disposed therebetween.

The publication US 2,454,332 discloses a refractor screen which can be used for street lights and has a Fresnel lens structure.

Often accidents occur because of unfavorable environmental conditions, such as poor visibility, so that an obstacle or a person can be perceived late. As a further factor to be considered in accidents, in many cases, the speed of movement of the accident causer as well as the accident victim comes into consideration, so that an available response time is relatively short due to higher speeds. In addition, a misjudgment of the accident causer on the actual (s) speed (s) is another accident factor that can be exacerbated by poor visibility. Such accidents are partly attributable to street lighting only insufficiently lit streets, sidewalks or crossings. With regard to traffic safety, well-lit traffic routes are therefore desirable.

Typically, high-pressure lamps, high-pressure mercury lamps or mercury-vapor lamps are used as street lighting lamps. For some time, light emitting diodes (LEDs) have been used more and more frequently as light sources. These have the fundamental advantage over the aforementioned bulbs that the energy consumption is lower, they have a long life and, for example, compared to high-pressure mercury lamps are environmentally friendly.

With regard to a good illumination of traffic routes in particular a high light intensity is desirable. While high-pressure mercury lamps have approximately a luminance of up to 15 × 10 ⁴ cd / cm ² (candelas per square centimeter), a white LED may have approximately 50 × 10 ⁶ cd / cm ² .

Already at a luminance of 0.75 cd / cm ² glare of the human eye can occur. Glare is caused by large differences in the luminance of a luminous means compared to the surrounding luminance in the visual field, so that the eye adapts to the higher luminance although the luminance of the surroundings is lower.

In particular, there may be an increased tendency for glare due to the high luminance of LEDs when people are looking directly into the light emitting diode.

Various measures can be taken to avoid glare.

For example, a radiating surface or radiating luminous surface can be increased so that the luminance in the field of view is more homogeneous. However, this has the disadvantage that more lamps such as LEDs must be used as actually required for adequate illumination, whereby the manufacturing or acquisition costs and operating costs rise. Furthermore, it is possible to provide a larger emitting luminous area and to operate the lighting means in a dimmed state or to operate light sources with a lower luminance, whereby still higher manufacturing or acquisition costs are available.

Another possibility would be to prevent glare by emitting diffuse or non-directional light. This could be achieved, for example, by the use of frosted glass panes, so-called opal umbrellas or other diffusers. A disadvantage of this embodiment, however, is that an illumination of a desired environmental area can not be made as targeted or accurate as without a diffuser, because light rays are uncontrolled broken or scattered at the diffuser and therefore randomly deflected or scattered in various directions. Thus, a part of the emitting light is also radiated in unwanted directions such as a house wall or in the direction of the sky, where it is useless or even disturbing. In other words, the efficiency of a Lighting lowered by a diffuse or uncontrolled radiation and it is only a poorly adjustable light distribution possible.

It is also conceivable in a radiation area, which would very likely lead to glare or to a particularly disturbing glare, to provide a diffuser or a cover or shielding. For example, it could be particularly disturbing if motorists were dazzled when looking forward to the road from a street lighting.

In addition, a viewer lampshades of street lights appear to be not homogeneously illuminated or illuminated when direct insights on the LED light source is possible and the LED has a very high light density, but as if the lampshade only punctiform or small area filled with light. The reason for this is in particular the fact that individual LEDs form, for example, a luminous area of about 1 × 10 ^-3 mm ² to 4 mm ² .

With regard to the energy efficiency of LEDs, it has hitherto been problematic to convert existing street lamps, which are equipped, for example, with high-pressure mercury lamps, to equipping with LEDs. In particular, this has not been possible for street lamps in mushroom form.

It is an object of the invention to provide a street lamp, by which a good illumination of an area to be illuminated is achieved while glare can be avoided. Furthermore, a street lamp is to be provided, which has optimal optical properties (such as illumination, glare and homogeneously illuminated lampshade), and also manufacturing and operating costs should be kept low. In particular, it is an object to provide a high light intensity (luminous flux per solid angle in cd) with the lowest possible luminance (in cd / m ² ) of a lampshade.

It is a further object of the invention to provide a street lamp, which allows to design based on an existing street lamp, a street lamp according to the invention.

According to the invention, this object is solved by the features of the independent claims. Preferred embodiments of the invention are the subject of the dependent claims.

One aspect of the present invention relates to a street lamp according to independent claim 1.

For the purposes of this invention, a "Fresnel linear Fresnel lens" is understood to mean a Fresnel lens with a positive focal length (f> 0, ie a converging lens), which has a first and a first focal point in each light passage point of the lens vertical second cutting plane such that the lens in the first cutting plane has the predetermined or fixed focal length f, while in the second cutting plane preferably has substantially no focusing effect, d. H. light incident parallel within the first cutting plane is focused in the focal length, while in the second cutting plane parallel incident light from the refractive shield also emerges substantially parallel again. The refractive screen thus has a pronounced astigmatic effect of a cylindrical lens. In this case, the main sections of at least one of the surfaces of the refraction screen, that is to say the directions of maximum and minimum surface refractive values of the corresponding surface, lie in the first or second sectional plane.

In other words, divergent light incident on the refractive screen and originating from a focal point of the refraction screen is refracted in parallel in an exit direction within the first sectional plane. While in conventional condenser lenses (such as lenses with approximately spherical surfaces) light rays passing through the lens parallel to an optical axis are collected at a single focal point spaced from the lens at focal length f, the refractive screen in a street lamp according to the invention is not shunted a single focal point, but characterized by a focal line, is focused on the incident parallel to the refractive screen light. This focal line lies in particular perpendicular to a vertical axis of the street lamp and intersects the above-mentioned first sectional plane perpendicular. The focal line is thus in particular in a plane perpendicular to the vertical axis. The plane thus also forms a horizontal plane of the street lamp. Due to the focusing effect in only one direction and the resulting focal line, the Fresnel collecting lens is referred to in this description as a "linear" Fresnel convergent lens.

The focal line preferably runs at least partially around the vertical axis of the street lamp, forming, for example, a circular line or at least a section of a circular line or a polygonal line or a section thereof. The two opposite directions defined by the vertical axis will be referred to hereinafter as the upward direction and the downward direction (or bottom-side direction, respectively).

In particular, the lines of intersection of the two lens surfaces with the first and second cutting planes form the main lines of the lens surfaces in the corresponding light passing point. The lines of intersection of at least one of the two lens surfaces with the first sectional plane has a plurality of Fresnel stages, between which the two surfaces do not run parallel to one another. On the other hand, the lines of intersection of the two lens surfaces with the second cutting plane are substantially parallel to one another. Depending on the embodiment, the lines of intersection of the two lens surfaces with the second cutting plane preferably extend at least in sections along two mutually parallel straight lines or they preferably form concentric circular rings at least in sections.

By arranging the at least one light source at a distance from the refracting screen that corresponds to "substantially" the focal length f, it can be understood herein that the deviation from the focal length is not greater than 10% of the focal length.

Preferably, cross-sections through the refractive screen are formed identically along different first cutting planes parallel to the vertical axis of the street lamp. In a particularly preferred manner, essentially all cross sections through the refraction screen along cutting planes which are perpendicular to a tangential plane of the refraction screen at an intersection of the sectional plane with a surface of the refraction screen and parallel to a vertical axis of the street lamp are identical or congruent to one another.

For example, the refractive screen may preferably be made substantially cylindrical, with its axis coinciding with the vertical axis of the street lamp.

In a further preferred embodiment, the refractive screen forms the lateral surface of a prism, ie essentially consists of a plurality of flat or flat or plate-shaped segments, which are arranged around the vertical axis. The at least one first light source is positioned between the vertical axis and the refractive screen.

In a further embodiment, the refractive screen essentially represents a hollow cylinder section which forms, for example, a circular cutout, in particular a quarter circle or a semicircle or a three quarter circle. Furthermore, the refractive screen can essentially represent a prism section. By section designs of the refractive screen, for example, street lamps may be suitable for attachment or placement on house walls or corners. In particular, the vertical axis is only partially enclosed or enclosed in sections.

In other words, the refraction shield is preferably at least partially rotationally symmetrical to the vertical axis of the street lamp. In this case, at least one discrete, particularly preferably one continuous rotational symmetry preferably occurs as rotational symmetry. Furthermore, at least one of the two lens surfaces or surfaces of the refractive screen preferably forms a cylinder jacket surface at least partially or in sections. In a further preferred embodiment, at least one of the two lens surfaces forms a conical surface at least partially or in sections.

For example, the refractive screen can essentially be formed as a hollow cylinder or as a hollow cylinder section which has circumferentially parallel sections or linear lens sections on an outer lateral surface, wherein the steps exiting the hollow cylindrical refractive screen light in a plane which intersects the vertical axis of the street lamp , bundles. In other words, the parallel steps form concentric circular rings relative to the vertical axis on the peripheral surface of the hollow cylinder.

Preferably, the street lamp comprises at least one lighting unit, which has a plurality of light sources, wherein the lighting unit is arranged substantially between the vertical axis of the street lamp and the refractive screen. The lighting unit is thus understood to mean in particular a receptacle for a multiplicity of light sources. In particular, the street lamp preferably comprises a plurality of first lighting units, each of which comprises a plurality of first light sources, wherein the plurality of first lighting units are arranged symmetrically with respect to one another about a rotation about the vertical axis of the street lamp.

Preferably, the light sources are light emitting diodes (LEDs), which are positioned or fixed in a single or multi-row arrangement on or in the lighting unit. Thus, the lighting unit comprises in particular a support element for lighting means such. B. LEDs. Preferably, lighting units may comprise so-called multi-chip LEDs. Preferably, multi-chip LEDs may include from about 10 to about 50 LED's, more preferably from about 18 to about 40 LEDs.

For example, at least one lighting unit comprise LEDs, wherein at least one LED of the lighting unit has a lens or comprises a collimator, which is adjustable with respect to the vertical axis of the street lamp at smaller to be illuminated solid angles at a steeper angle, while at a larger to be illuminated solid angle a correspondingly flatter angle can be adjusted.

In particular, the lighting unit can be designed in one or more parts. Preferably, the lighting unit is in holders or holding devices of conventional street lamps, which are, for example, according to manufacture equipped with high-pressure mercury vapor or mercury vapor lamps, could be used or adapted.

Preferably, the at least one illumination unit comprises a reflector screen which is suitable for reflecting light emitted by the light sources (illuminants) in a specific direction or a specific directional range or emission range. Preferably, the reflector screen comprises a mirror or a reflecting surface.

Further preferably, a primary emission direction or main emission direction of the light sources of the illumination unit is variably adjustable in a state mounted on the street lamp. Preferably, radiation directions are adjustable as a function of angles of incidence of the illumination unit.

In particular, a emission direction of light of the luminous means is to be understood as a main emission direction or primary emission direction, which has a relatively high emission density or intensity in comparison to other emission directions of the luminous means. In particular, the primary emission direction can be understood to be that emission direction which has the highest emission density or intensity. In particular, the primary emission direction can correspond to a core or main ray of the luminous means. Furthermore, the emission density is the luminance (cd / cm ² ).

In a further preferred embodiment, the refractive screen or segments of the refraction screen and / or the at least one illumination unit can be adjusted as a function of a spatial angle to be illuminated.

If, in one embodiment of a lighting unit, LEDs are preferably used as lighting means, the first lighting unit for tuning with regard to an operating temperature of a street lamp can essentially comprise a metallic material as base material for the lighting unit. The lighting unit preferably comprises aluminum. Further preferably, other good heat conducting materials can be used.

Further preferably, the street lamp comprises at least one heat sink, which dissipates or compensates for the waste heat or power dissipation which arises during operation of the street lamp. In particular, heat sinks are advantageous in order to keep the radiation power constant or high. Because the radiation power of LEDs decreases at an ambient temperature of about 100 ° C to about 50% or less.

Particularly preferably, the street lamp comprises a plurality of first lighting units, each of which comprises a plurality of first light sources, wherein the plurality of first lighting units are arranged symmetrically to each other with respect to a rotation about the vertical axis of the street lamp. Particularly preferably, all the first light sources of the plurality of illumination units are arranged at a distance from the refraction shield, which corresponds essentially to the focal length f of the refraction shield.

The first lighting units thus preferably form segments. For example, three to five, three to six or eight segments may be arranged about the vertical axis of the street lamp. In particular, the plurality of lighting units in a polygonal. Formation can be arranged around the vertical axis. In an embodiment where the street lamp is intended to be mounted on a corner of the building and the refractory screen therefore essentially has a ¾-circle shape, the lighting units are also provided in a ¾-circle arrangement.

Furthermore, it is advantageously possible by means of a segmented embodiment of the lighting units to deliberately avoid illumination in a primary emission area if, for example, no illumination is desired in such a radiation area. This could, for example, be the case if a radiation area were to radiate exactly into a window of a local resident.

The first light sources are preferably arranged at a distance from the refraction shield which deviates from the focal length f by not more than 10 mm, preferably not more than 5 mm, most preferably not more than 2.5 mm.

Further preferably, the focal length f of the street lamp is at a value in the range of about 10 mm to about 200 mm, preferably in the range of about 20 mm to about 100 mm, more preferably in the range of about 30 mm to about 50 mm, on most preferably in the range of about 35 mm to about 40 mm.

Further preferably, the at least one first light source is at a distance from the vertical axis in the range of about 20 mm to about 200 mm, preferably in a range of about 40 mm to about 100 mm, more preferably in a range of about 50 mm to about 70 mm arranged.

More preferably, each of the first illumination units is configured to emit light such that at least about 50%, preferably at least about 60%, more preferably at least about. 70%, more preferably at least about 80%, most preferably at least about 90%, of the radiated light output within a first vertical emission angle of from about 60 ° to about 100 °, preferably from about 70 ° to about 95 °. In this case, the first vertical emission opening angle is preferably centered about a first central emission direction of the first illumination unit, which includes a first incidence angle of the first illumination units with the vertical axis downwards, wherein the first incidence angle is in a range of about 65 ° to about 85 °, preferably in one region from about 70 ° to about 80 °, most preferably about 75 °. The first illumination unit is thus preferably arranged inclined in the approximately 15 ° relative to the horizontal direction, that is to say under the direction of the downward direction.

In particular, the term "vertical emission opening angle" is to be understood as meaning the opening angle, formed in a sectional plane through the vertical axis of the streetlight, of the light cone illuminated by a lighting unit. Together with the angle of attack of the corresponding illumination unit, the vertical emission angle thus describes limits of the emission upwards and downwards. The "vertical Abstrahlöffnungswinkel", for example, depend on the lamps used, the arrangement and number of lamps. Furthermore, the "vertical emission angle" may be influenced by use and adjustment of a reflector. At a first Abstrahlöffnungswinkel or first vertical Abstrahlöffnungswinkel of, for example, about 90 ° and a first angle of, for example, about 15 ° thus preferably a large part of the light emitted from the first illumination unit light in an angular range between about 30 ° relative to the horizontal direction upwards and about 60 ° emitted downwards relative to the horizontal direction.

Preferably, the street lamp comprises a plurality of second lighting units, each of which comprises a plurality of second light sources, the plurality of second lighting units being particularly preferably arranged symmetrically with respect to each other about a rotation about the vertical axis of the street lamp, and in particular each of the second lighting units being designed to emit light in such a way to emit at least about 50%, preferably at least about 60%, even more preferably at least about 70%, more preferably at least about 80%, most preferably at least about 90% of the radiated light output within a second vertical coverage angle of about 60 ° to about 100 °, preferably from about 70 ° to about 95 °. In this case, the second vertical emission opening angle is preferably centered about a second central emission direction of the corresponding second illumination unit, which includes a second angle of incidence of the corresponding second illumination units with the vertical axis downwards, the second angle of attack being in a range of about 15 ° to about 45 °, preferably in a range of about 20 ° to about 40 °, most preferably about 30 °. The second illumination unit is thus preferably arranged inclined in the approximately 60 ° relative to the horizontal direction to below so to the downward direction.

Further preferably, at least about 50%, preferably at least about 70%, most preferably at least about 90%, of the light output radiated by the second illumination units does not impinge on the refractive screen, but is radiated particularly below the refraction screen.

Further preferably, the second light sources are at a distance from the vertical axis in the range of about 5 mm to about 100 mm, preferably in a range of about 10 mm to about 50 mm, more preferably in a range of about 20 mm to about 40 mm arranged.

Preferably, the second light sources in a direction parallel to the vertical axis relative to the first light sources are in a range of about 5 mm to 300 mm, preferably in a range of about 10 mm to about 100 mm, most preferably in a range of about 30 mm spaced about 60 mm apart.

Further preferably, the light output radiated by the second illumination units is in a range of about 5% to about 100%, preferably in a range of about 10% to about 75%, even more preferably in a range of about 20% to about 40% of light output emitted by the first lighting units.

Further preferably, the refractive screen has a distance to the vertical axis in the range of about 30 mm to about 300 mm, preferably in the range of about 50 mm to about 200 mm, more preferably at about 80 mm to about 120 mm. In another embodiment, the Refraction screen at a distance from the vertical axis of about 50 cm.

Preferably, the refractive shield in the horizontal direction (ie perpendicular to the vertical axis) has an extension (eg diameter) in the range of about 40 mm to about 700 mm, more preferably in the range of about 80 mm to about 500 mm, most preferably ranging from about 100 mm to about 300 mm. In particular, in a hollow cylindrical design, the refractive screen preferably has a diameter of about 60 mm to about 600 mm, particularly preferably in the range of about 100 mm to about 300 mm. Furthermore, the refractive screen in a prismatic design, for example in a hexagonal arrangement of the segments, preferably has a key width in the range from about 40 mm to about 700 mm, particularly preferably in the range from about 100 mm to about 300 mm.

Further preferably, the refractive screen extends in a direction parallel to the vertical axis in a range of about 10 mm to about 300 mm, preferably in a range of about 30 mm to about 200 mm, most preferably in a range of about 80 mm to about 130 mm. In other words, the refractive screen preferably has a height or length of about 10 mm to about 300 mm.

Preferably, the refractive screen has an optical center that is in a range of about 1 mm to about 20 mm, preferably in a range of about 1 mm to about 10 mm, more preferably in a range of about 3 mm to about 7 mm lower is arranged as the at least one first light source, d. H. a horizontal plane (ie, a plane perpendicular to the vertical axis) through the optical center is offset by the specified range relative to a horizontal plane through the at least one first light source in the downward direction. In other words, the optical center is opposite to the at least one first light source in a direction parallel to the vertical axis of from about 1 mm to about 20 mm, preferably from about 1 mm to about 10 mm, more preferably from about 3 mm to about 7 mm offset below.

In particular, the optical center designates a position on the refractive screen in which substantially no prismatic effect occurs. In other words, light that passes through the optical center emerges at substantially the same angle as it entered the refractive screen.

Due to the offset arrangement of the optical center to the at least one light source to the bottom direction, the effective prismatic effect or average prismatic effect of the refractive screen is influenced in such a way that for the light beam impinging on the refraction screen an additional deflection or refraction to the bottom direction achieved.

In particular, the term "bottom-side direction" is to be understood as meaning a direction parallel to the vertical axis of the street lamp, which is oriented towards the ground in the application state of the lantern, that is to say downwards.

More preferably, at least one lens surface of the refractive screen comprises a plurality of steps spaced at a mutual distance in the range of about 0.2 mm to about 2 mm, preferably not greater than about 1 mm, more preferably in the range of about 0.4 mm about 0.8 mm, most preferably about 0.6 mm. In other words, the refractive screen or the Fresnel linear lens has a step width of about 0.2 mm to about 2 mm. The steps of the refraction shield extend in particular in a normal direction to the vertical axis or a circumferential direction of the refractive screen or, in the case of a cylindrical refractive screen, along the cylinder curvature, that is to say in particular within a horizontal plane. Thus, the steps are substantially one above the other in a direction along the vertical axis and the length of the refractive screen and arranged annularly around the lateral surface of the refractive screen.

A further aspect relates to the use of the street lamp for illuminating a road and / or a footpath comprising one or more features of the street lamp described above, wherein the at least one first light source and the refractive screen use in a height of about 3 m to about 6 m, preferably are arranged at a height of about 4 m to about 5 m above the ground or the road or the footpath. In a preferred embodiment, the street lamp for this purpose comprises an approximately 4 m long lamppost, which extends substantially along the vertical axis of the street lamp.

In particular, the height of the refracting screen and the at least one first light source refers to a distance from the floor or pavement surface to a lower edge of the refracting screen or an upper edge of the street lamp or a center of the street lamp.

Brief description of the figures

The invention will now be described by way of example with reference to exemplary embodiments with reference to the accompanying drawings. In particular, individual features of the above and / or below described aspects and / or embodiments, detached from the respective aspect or the respective embodiment, can be combined to form further embodiments.

It shows:

1 FIG. 2: a schematic representation of a section of a street lamp in section, in particular through a first sectional plane, FIG.

2 : a schematic representation of a street lamp in section,

3A a light distribution curve of a first illumination unit,

3B a light distribution curve of six first lighting units, the street lamp being essentially hexagonal,

4 a light distribution curve of six first lighting units and six second lighting units, the street lamp being substantially hexagonal,

5 a light distribution curve of six first lighting units and six second lighting units, wherein the street lamp is substantially hexagonal and the second lighting units are dimmed,

6 a distribution of illuminance on the ground under a street lamp according to the invention,

7A : schematic representations of a street lamp with refractive screen from the perspective of a viewer,

7B : schematic representations of a street lamp without refractive screen from the perspective of a viewer,

8th FIG. 2: a schematic representation of a street lamp with regard to an arrangement of a focal line and an optical center, FIG.

9A C: Light distribution curves of a street lamp with respect to deviations and tolerances in a preferred embodiment,

10A C: Light distribution curves of a street lamp with respect to deviations and tolerances in a preferred embodiment,

11A C: Light distribution curves of a street lamp with respect to deviations and tolerances in a preferred embodiment.

Detailed description of the figures

In the following, objects, sections, regions and parts, which are shown in different figures but have substantially the same functions and / or the same properties, are given the same reference numerals.

1 shows a street lamp 100 , which first bulbs 2 (Light sources), a first lighting unit 4 , a refraction screen 6 and a cover 10 includes. Furthermore, the street lamp includes 100 a vertical axis VA. The refraction screen 6 has an optical center OZ and a focal line BL. The street lamp shown 100 is according to the representation of 1 shown in section along a first sectional plane, wherein the first sectional plane includes the vertical axis VA.

The bulbs 2 (not shown in detail, but indicated as circles) are at the first lighting unit 4 arranged and radiate in an operating state light substantially in the direction of the refractive screen 6 from. That of the bulbs 2 radiated light divergently hits the refractive screen 6 on. The divergently emitted light forms a vertical emission angle 14 , which comprises approximately an angular range of about 60 ° to 100 °. Preferably, a majority of the radiated light output or the radiated light is within the Abstrahlöffnungswinkels 14 radiated.

Preferably, the light sources 2 each own or a common lens or primary optics (not shown), which from the light sources 2 radiated light bundles such that it has a Abstrahlöffnungswinkel 14 from about 60 ° to about 100 °.

Furthermore, the first lighting unit 4 additionally or alternatively to the at the bulbs 2 arranged primary optics comprise at least one reflector, which then also to optimize the Abstrahlöffnungswinkels 14 and / or an increase in the radiated light output in the Abstrahlöffnungswinkels 14 contributes.

Preferably, as lighting means 2 Multi-chip LEDs used.

After the light the refraction screen 6 has passed through, it is as directed, in particular substantially parallel, light rays 8th radiated into the environment. In particular, the radiated light (parallel or divergent light rays 8th ) substantially at an angle of about 75 ° to about 68 ° with respect to the vertical axis VA, that is, a bottom-side direction BR of the vertical axis VA, radiated, wherein a luminance over a radiating 12 of the refraction screen 6 is preferably substantially homogeneous, or preferably does not appear as one or more point light sources when viewed.

Specifically, in an angle range δ, which preferably extends in a range of a normal direction to the vertical axis VA to about 10 ° or even 15 ° from the normal direction corresponding to the application of the street lamp horizontal, in a downward or bottom direction BR, the luminance is minimal. In this way, glare in the horizontal direction is avoided in a particularly efficient manner, and a good illumination, in particular of a road or a footpath, is achieved.

The refraction screen 6 has in particular stages 18 or linear Fresnel stages. In a direction along a parallel to the vertical axis VA is a plurality of stages 18 arranged side by side or one above the other. In particular, the stages 18 on a lateral surface of the refractive screen 6 arranged, with the steps 18 either on an outside (as in 1 shown) or may be arranged on an inner side. In particular, an inner side is to be understood as meaning a side of the refraction screen 6 which corresponds to the lighting means 2 or the vertical axis VA faces.

In a further embodiment, the stages 18 on an inside and an outside of the refraction screen 6 be arranged. The steps 18 extend along a radial or coaxial direction on one or both mantle surfaces of the refractive screen 6 , Especially if the refraction screen 6 designed as a hollow cylinder, run the stages 18 linear along the cylinder curvature. Therefore, cross sections through the refraction screen 6 , Wherein the cross sections run along different first cutting planes, identical.

The first lighting unit 4 is relative to the vertical axis VA by a first angle of attack 16 tilted, wherein preferably the first lighting unit 4 adjustable at the street lamp 100 is arranged, so that advantageously the radiating light optimally on the refractive screen 6 can be aligned. The first angle of attack 16 is preferably selected or adjustable depending on the application or boundary conditions with regard to illumination of a vehicle or sidewalk.

The lighting unit 4 or the bulbs 2 are preferably between the vertical axis VA and the refractive screen 6 arranged. Furthermore, the bulbs 2 from the refraction screen 6 at a distance approximately equal to the focal length f of the refractive screen 6 corresponds, arranged. Depending on the embodiment, the bulbs 2 essentially positioned slightly above the focal line BL. In a further embodiment, the lighting means 2 are substantially slightly wider than the focal length f corresponding to the refractive screen 6 spaced.

The term "a little further" here describes a deviation from the precisely defined value of the focal length f. In particular, this may be a deviation without significant change in the desired properties. For example, if the desired property (s) is considered to be a desired property, "a little further" may describe a departure from that ideal property by less than about 10%, less than about 5%, or less than about 3%.

Like from the 1 can be seen, the focal line BL and the optical center OZ are not arranged at a height compared to each other. Rather, the focal line BL is arranged slightly higher than the optical center OZ, so that the connecting line between the focal line BL and the optical center OZ results in a focal axis which slopes downwards from the focal line BL towards the optical center by an inclination angle Nw relative to the horizontal direction The angle of inclination Nw is preferably in the range of about 1 ° to about 20 °, more preferably in the range of about 2 ° to about 10 °, more preferably in the range of about 3 ° to about 7 °, most preferably at about 5 °.

This is also on the presentation in 8th referring to the relative arrangement of the focal line BL and the optical center OZ with respect to the street lamp 100 again schematically shows. In particular, the relatively staggered arrangement of the optical center OZ and the focal line BL is determined by the design of the refractive screen 6 , in particular by the formation of the linear Fresnel stages 18 , causes.

In particular, the optical center OZ denotes a position on the refractive screen 6 in which essentially no prismatic effect occurs. In other words, light passing through the optical center OZ emerges at substantially the same angle as it does in the refractive screen 6 occurred.

Due to the staggered arrangement of the optical center OZ to at least one light source is the effective prismatic effect or average prismatic effect of the refractive screen 6 influenced in the way that for that on the refraction screen 6 striking diverging light bundles in an additional deflection or refraction is achieved towards the bottom-side direction BR.

With reference to the 1 is the objective with regard to the street lamp 100 in that on the one hand the light bundling and deflection as well as the apparent widening of the light source from a small LED surface or illumination unit onto the surface of the refraction screen 6 is reached. These requirements can be especially with the help of Brechungsschirms 6 designed as a linear Fresnel condenser lens meet: the stages 18 of the refraction screen 6 are arranged transversely to the vertical axis VA (cf., with a lamppost) preferably circumferentially on the outside of the disc. The parameters of the Fresnel condenser lens are: focal line, aperture or height of the refractive screen, which refers to the extension of the refraction screen in a direction parallel to the vertical axis VA, and focal axis. The focal axis leads through the focal point and the optical center and is in Fresnel lenses with symmetrical prism structure perpendicular to the focal plane and refractive screen. In the present case of an asymmetrical prism structure, the optical center is preferably a point of the screen through which light rays run whose incident direction is parallel to the exit direction.

The LED surface or lighting unit is located in the focal plane but above the focal line. The focal axis is inclined downwards by the angle Nw. The light beams of the LEDs are thereby deflected by approximately 20 ° parallel to the bottom. In this angle range, a viewer sees the refraction screen glowing homogeneously. The angle range from a horizontal or normal to the vertical axis VA up to 20 °, however, has minimal luminance.

2 shows a street lamp 200 which is essentially the street lamp 100 of the 1 equivalent. The street lamp 200 , in particular the refraction screen 6 may preferably be substantially cylindrical. Alternatively, the street lamp 200 , In particular, the refractive screen or its cross section in the horizontal direction, substantially correspond to a hexagon. In a substantially hexagonal arrangement of the street lamp is in particular the refractive screen 6 divided into six equal segments, each segment of the refraction screen 6 ever a first lighting unit 4 and a second lighting unit 20 assigned. As lamps for the street lamp LEDs are preferably used.

In the 2 In particular two opposite segments are shown. While the bulbs 2 are arranged to the refractive screen 6 to illuminate as completely as possible, are bulbs 22 , which at the second lighting unit 20 are arranged aligned to the refractive screen 6 little or no light. In other words, the two form lighting units 4 . 20 or bulbs 2 . 22 together with the refraction screen 6 two different lighting tasks or functions. While the first lighting unit 4 together with the refraction screen 6 is intended to illuminate preferably for illuminating a first, further radiation area with respect to a radial distance from the vertical axis VA, the second lighting unit is intended 20 a second, closer radiation area, which is radially less spaced from the vertical axis VA than the first radiation area, illuminate.

In one embodiment, the first lighting unit 4 with the bulbs 2 a radiation characteristic of +/- 15 ° in the vertical and +/- 60 ° in the horizontal direction, and directs the light emitted by it completely to the refractive screen 6 , The second lighting unit 20 with the bulbs 22 has a radiation characteristic of +/- 30 ° in the vertical and +/- 60 ° in the horizontal direction and is responsible for the lighting of the soil. The luminous flux of both lighting units 4 . 20 with the bulbs 2 . 22 is at 200 lm (lumens) and is preferably adjustable or dimmable.

In this embodiment, the refractive screen 6 a focal length f of about 40 mm, an aperture of about 140 mm, a vertical extension parallel to the vertical axis VA of about 100 mm, an angle of inclination Nw of about 5 ° and a number of Fresenel stages 18 from about 122 to 170 with a focal plane in a direction parallel to the vertical axis VA relative between the optical center OZ and a relatively higher end of the refractive screen 6 related to a distance to the ground. Preferably, the focal plane for the aperture selected here is about 30 mm below a top edge of the refractive screen (or a street lamp cover). Preferably, the street lamp in this embodiment has a diameter of about 195 mm.

3A shows a light distribution curve of a first lighting unit or LED area, comparable to a lighting unit 6 from the 1 and 2 ,

3B shows a light distribution curve of six first lighting units or LED area, the street lamp is designed substantially hexagonal.

From the light distribution curve of 3A and 3B it turns out that at one Overall efficiency of ε = 82% about 70% of the light rays in the angular range 195 ° -210 ° (or 330 ° -345 °) scattered. 12% of the light rays follow the path past the refraction screen or are reflected on the lower inside of the refraction screen and reach the bottom.

The focal length is 38 mm, the position of a passage of the focal axis through the refractive screen at approximately 35 mm below the upper edge of the refractive screen (or below the cover) and the latter Inclination angle Nw at 5 °. The refractive screen comprises 167 steps and a height (aperture) of 100 mm.

4 shows a light distribution curve of six first lighting units and six second lighting units, the street lamp is designed substantially hexagonal. In other words, a total of twelve lighting units or LED surfaces are arranged on the street lamp.

The light intensity distribution of the arrangement with all 12 lighting units or LED surfaces illustrates the emission characteristics of the street lamp. The position of the second illumination units or lower LEDs (angular range of radiation +/- 30 °) is chosen so that on the one hand the refraction screen is illuminated as little as possible and on the other hand, the illumination of the soil is ensured evenly from the lamppost to a few meters away.

Each lamp or LED has a luminous flux of 200 lm (lumens). With an overall efficiency of ε = 88%, 46% of the luminous flux goes into the lateral radiation and 42% into the direct lighting of the floor. The light distribution curve in 4 shows that the six underlying LED surfaces or second lighting units dominate or have a higher luminous intensity and also influence the lateral radiation. In the following figure, therefore, the power of the LEDs below has been reduced (dimmed) from 200 lm to 50 lm.

5 shows a light distribution curve of six first lighting units and six second lighting units, the street lamp is designed substantially hexagonal and the second lighting units are dimmed. In this embodiment, the lighting means of the second lighting units are dimmed or reduced from 200 lm to 50 lm.

6 shows a distribution of illuminance on the ground under a street lamp according to the invention, the street lamp is about 4 m away from the ground.

The illuminance is the quotient of the incident luminous flux and the size of the receiver surface. With reference to the street lamp, the illuminance indicates the ratio of the luminous flux incident on the floor to the illuminated surface of the floor. According to the 6 the illuminated or receiver surface and the street lamp are 4 m apart in the direction of the vertical axis of the street lamp. In an area of about 3 m in a normal direction to the vertical axis VA of the street lamp are on the receiver surface or the ground (such as the road or the footpath) on average 9 lux before. In other words, within a radius of about 0 m to 3 m from the lamppost (which preferably coincides with the vertical axis), an average of about 9 lux and a maximum of about 14 lux can be measured. In one embodiment, the first lighting units contribute about only about 2 lux to a lighting of the floor or a floor area.

7A shows a street lamp with a refraction screen from the view of a viewer. As can be seen, the lateral surface of the refraction screen appears as a substantially homogeneously luminous surface. In other words, a viewer, who looks at the lantern from a distance of about 6 m to 7 m, gets the impression that it is substantially homogeneous or has large luminous surfaces.

7B shows a street lamp without refractive screen from the perspective of a viewer who looks from a same position in the street lamp as a viewer of the street lamp shown in 7A , It can be seen here that the luminous or emitting luminous means or lighting units can be exactly recognized by a viewer in their delimitation or areal extent. In other words, a viewer looks right into the lighting unit and is blinded.

Compared to the luminous surfaces of the street lamp, as in 7B shown, the glowing areas of the streetlight appear in 7A in the vertical about three times as large.

In the simulation model for creating a light distribution curve, all dimensions of the lantern, the positions and angles of incidence of the lighting units and their emission characteristics can be recorded as variables of the system. (In particular, among the LED surfaces or lighting units to understand the exit surfaces of the collimators.) Also variables are the parameters of Fresnel's convergent lens (such as focal length f, design of the stages, position of the optical center). The simulation program uses the so-called 3D-ray-tracing method, in which individual light beams are tracked through the structure of the system to be considered. Optically effective surfaces are described by transition planes at which reflection or refraction occurs. Beams of light passing through material undergo absorption. At the starting point (light source), with the aid of the Monte Carlo method, it is possible, in the statistical sense, to generate a sufficiently large quantity of light beams which are emitted in different directions according to the boundary conditions or functional specifications. An evaluation of all rays reflects the optical properties of the system, it is possible to consider various aspects and factors separately. In order to determine the parameters of the Fresnel condenser lens, initially only the upper LED row in the simulation model is considered.

9A C show light distribution curves of a street lamp with respect to deviations and tolerances in preferred embodiments. In the construction of a street lamp information about tolerances of positions and angles of the lighting units or LED surfaces are preferred. Preferably, an area around the optimum value is set for each variable of the LED position. The start and end of the range of variation are determined, in particular, by significant changes (eg in the light distribution curve) after data acquisition. The tolerance range is given with half the range of variation. This shows directly what the exceeding of the tolerance ranges for consequences has on the appearance of the lantern. The variables of the Fresnel lens are fixed in this analysis ("fixed").

Specifying the value determined in the simulation, the variables of the system are: The installation height below the cover Z: = 20 mm with a preferred variation range of about 15 mm to about 25 mm, the distance from the lamp post or the vertical axis R: = 60 mm with a preferred variation range of about 55 mm to about 65 mm, the angle of attack of the LED surfaces a: = 75 ° with a preferred variation range of about 70 ° to about 85 °. The variation of the installation height Z has the greatest influence on the emission characteristics (angle) but it also shows a dependence of the efficiency ε.

In the 9A to C different installation heights (Z = 15 mm, Z = 20 mm, Z = 25 mm) have been set measured from the cover of the street lamp. Like that 9A to C can be seen, with decreasing installation depth Z (15 mm), the angular range in which is radiated, smaller and narrower, but the efficiency decreases. Conversely, the ratios at Z = 25 mm. It can therefore be set in this embodiment, a preferred tolerance range of about 17.5 mm to about 22.5 mm.

10A C show light distribution curves of a street lamp with respect to deviations and tolerances in a preferred embodiment in which the distance R is varied. Exceeding the tolerance limit with increasing distance R (first lighting unit or first light sources closer to the refractive screen) causes a reduction in the efficiency ε and a change in the radiation in the required angular range. As the distance R (closer to the vertical axis) becomes smaller, the efficiency becomes greater, but here the decrease in homogeneity in the illumination of the refraction screen must be taken into account.

11A C show light distribution curves of a street lamp with respect to deviations and tolerances in a preferred embodiment in which the angle of attack of the first lighting units is varied. Exceeding the tolerance limits of the angle of attack (here designated α) results in a non-uniform radiation (α ≥ 80 °) and a reduction in the efficiency.

On the other hand, increasing reflections occur in the interior space at a very small angle of attack (eg α = 70 °) and here, too, the refraction screen is no longer illuminated homogeneously. It can be set here a preferred tolerance range of 72.5 ° to 80 °.

LIST OF REFERENCE NUMBERS

100

street lamp

2

Lamp

4

first lighting unit

6

refraction screen

8th

light rays

10

cover

12

radiating

14

vertical emission angle

16

first angle of attack

18

stages

δ

Angular range with minimum luminance

Nw

tilt angle

OZ

Optical center

BL

focal line

VA

vertical axis

BR

bottom-side direction

200

street lamp

20

second lighting unit

22

Lamp

24

second angle of attack

Claims (11)

Street lamp ( 100 ; 200 ) comprising a refractive screen formed as a linear Fresnel conical lens ( 6 ) with a focal length f, the refractive screen ( 6 ) a plurality of stages ( 18 ), which have a mutual distance in the range of about 0.4 mm to about 0.8 mm, at least a first illumination unit ( 4 ), which substantially between a vertical axis (VA) of the street lamp ( 100 ; 200 ) and the refractive screen ( 6 ), wherein the first illumination unit ( 4 ) a plurality of first light sources ( 2 ) and is adapted to emit light in such a way that at least about 50% of the radiated light power within a vertical Abstrahlöffnungswinkels ( 14 ) from about 60 ° to about 100 °, which by a first angle ( 16 ) of the first lighting unit ( 4 ) is centered relative to the vertical axis (VA), wherein the first angle of attack ( 16 ) is in a range of about 65 ° to about 85 °, wherein at least a first light source of the first illumination unit ( 4 ) at a distance from the refractive screen ( 6 ), which is substantially the focal length f of the refractive screen ( 6 ) corresponds; and at least one second illumination unit ( 20 ), which a plurality of second light sources ( 22 ) and is adapted to emit light in such a way that at least about 50% of the radiated light power lies within a vertical emission angle of about 60 ° to about 100 °, which by a second angle ( 24 ) of the second illumination unit ( 20 ) is centered relative to the vertical axis (VA), wherein the second angle of attack ( 24 ) is in a range of about 15 ° to about 45 °. Street lamp ( 100 ; 200 ) according to claim 1, wherein cross-sections through the refractive screen ( 6 ) along different first cutting planes parallel to the vertical axis (VA) of the street lamp ( 100 ; 200 ) are formed identically. Street lamp ( 100 ; 200 ) according to one of claims 1 to 2, wherein the first light sources at a distance from the refractive screen ( 6 ) deviating from the focal length f by not more than 10 mm, preferably not more than 5 mm, most preferably not more than 2.5 mm, and the spacing of the first light sources from the refractive screen ( 6 ) deviates by no more than 10% from the focal length f. Street lamp ( 100 ; 200 ) according to one of claims 1 to 3, wherein the focal length f has a value in the range of about 10 mm to about 200 mm, preferably in the range of about 20 mm to about 100 mm, more preferably in the range of about 30 mm to about 50 mm, most preferably in the range of about 35 mm to about 40 mm. Street lamp ( 100 ; 200 ) according to one of claims 1 to 4, which a plurality of first lighting units ( 4 ), each of the first lighting units ( 4 ) is adapted to emit light such that at least about 50%, preferably at least about 60%, more preferably at least about 70%, most preferably at least about 80% of the radiated light power is within a vertical emission angle (FIG. 14 ) from about 60 ° to about 100 °, preferably from about 70 ° to about 95 °, which is about the first angle of attack ( 16 ) of the first lighting units ( 4 ) is centered relative to the vertical axis (VA), wherein the first angle of attack ( 16 ) is in a range of about 65 ° to about 85 °, preferably in a range of about 70 ° to about 80 °, most preferably about 75 °. Street lamp ( 100 ; 200 ) according to one of claims 1 to 5, which comprises a plurality of second illumination units ( 20 ), wherein the plurality of second illumination units ( 20 ) symmetrical with respect to a rotation about the vertical axis (VA) of the street lamp ( 100 ; 200 ) are arranged, and wherein each of the second lighting units ( 20 ) is adapted to emit light such that at least about 50%, preferably at least about 60%, more preferably at least about 70%, most preferably at least about 80% of the radiated light output is within a vertical emission angle of about 60 ° to about 100 ° , preferably from about 70 ° to about 95 °, which by the second angle of attack ( 24 ) of the second illumination units relative to the vertical axis (VA) is centered, wherein the second angle of attack ( 24 ) is in a range of about 15 ° to about 45 °, preferably in a range of about 20 ° to about 40 °, most preferably about 30 °. Street lamp ( 100 ; 200 ) according to claim 6, wherein at least about 50% preferably at least about 70%, most preferably about 90% of the second lighting units ( 20 ) radiated light power not on the refraction screen ( 6 ) meets. Street lamp ( 100 ; 200 ) according to any one of claims 6 to 7, wherein the of the second lighting units ( 20 ) in a range of about 5% to about 100%, preferably in a range of about 10% to about 75%, even more preferably in a range of about 20% to about 40% of that of the first illumination units ( 4 ) emitted light power is. Street lamp ( 100 ; 200 ) according to any one of claims 1 to 8, wherein the refractive screen ( 6 ) in a direction parallel to the vertical axis (VA) in a range of about 10 mm to about 300 mm, preferably in a range of about 30 mm to about 200 mm, most preferably in a range of about 80 mm to about 130 mm. Street lamp ( 100 ; 200 ) according to one of claims 1 to 9, wherein the refractive screen ( 6 ) has an optical center (OZ) that is opposite to the at least one first light source in a direction parallel to the vertical axis (VA) of from about 1 mm to about 20 mm, preferably about 1 mm to about 10 mm, more preferably about 3 mm is offset to about 7 mm. Use of the street lamp ( 100 ; 200 ) for illuminating a road and / or a footpath comprising the features of claims 1 to 10, wherein the at least one first light source and the refractive screen ( 6 ) are arranged at a height in the range of about 3 m to about 6 m, preferably at a height of about 4 m to about 5 m above the road and / or the footpath.

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