A STREET LIGHTING ARRANGEMENT

Abstract

 Present invention relates to a street lighting arrangement comprising in the casing having a planar window LED light sources attached to the surface S0 of the cooling element. Each LED light source is surrounded by three reflecting surfaces S1, S2, S3, beginning closely from the surface S0 of the cooling element. Main reflecting surface S1 of the LED light source has trapezoidal shape. Main reflecting surface S1 is adjoined by two lateral triangular reflecting surfaces S2 and S3. Second lateral triangular reflecting surface S3 is connected by its edge to the fourth triangular reflecting surface S4. Reflector surfaces of two adjacent LED light sources are combined into a single reflector module by the connection of the edge of the fourth triangular reflecting surface S4 of one LED light source to corresponding edge of the second lateral triangular reflecting surface S3 of the adjacent LED light source.

Description

Technical Field

[0001] This invention relates to the field of lighting technology. More specifically, it relates to a street lighting arrangement with LED light source attached to a lamppost or other structure (e.g. exterior wall of a building or civil engineering works).

Background Art

[0002] As regards many streetlights, the reflector of the light source has relatively complicated shape, i.e. it has at least one concave and complicated reflecting surface with variable convexity. Manufacturing of such convex reflecting surface is relatively complicated and expensive.

[0003] Many streetlights have for a light source a reflector with relatively complicated shape, i.e. the reflector has at least one complicated concave reflecting surface with variable convexity. Manufacturing of such convex reflecting surface with precision is relatively complicated and expensive.

[0004] From international patent application WO2009052094A1 (publ. 23.04.2009) is known a roadway luminaire comprising in a housing as a base a cooling element to which several reflector elements are attached and where into the openings of reflector element are installed LED light sources which are supported on the base.

[0005] From the United States patent application US20100202140A1 (publ. 12.08.2010) a street lighting arrangement is known. That street lighting comprises a in the housing with a planar window, a LED light source, a reflector of a LED light source, a cooling element, and where each LED light source and each reflecting surface of the reflector is directed towards the plane of the window at an angle.

[0006] The reflector elements of the known solutions from the aforesaid documents mainly comprise planar surfaces but the structure of the described reflector elements is relatively complicated and their manufacturing is troublesome.

Summary of invention

[0007] The aim of the invention is to provide a street lighting arrangement that is easy to manufacture relatively inexpensively and having structure of the reflector as simple as possible. In addition, the aim is to attain a structure of the reflector, which can be used for forming a reflector module, which can be used to configure different lighting fixtures. The aim is also to attain a reflector, which will distribute the light relatively evenly to the designed area.

[0008] Present invention provides a reflector for a LED light source, which consists of a limited number of simple planar elements for each LED light source.

[0009] Such reflector is suitable for mass production since the dies and/or moulds necessary for its manufacturing are many times simpler and cheaper compared to the dies and moulds needed for manufacturing of reflectors comprising the concave reflecting surfaces with variable convexity. Also the reflector arrangement according to the invention allows simple formation of reflector modules with more than one LED light source.

[0010] The effect of the invention is achieved by combining the COB type LED light source with a reflector comprising a limited number of simple planar elements.

[0011] According to invention a street lighting arrangement is provided which comprises in a casing with a planar window at least one LED light source, at least one reflector of the LED light source, at least one cooling element, and where each LED light source and each reflecting surface is at an angle in relation to the plane of the window. The preferable embodiment comprises a planar window.

[0012] In the street lighting according to the invention, each LED light source is attached by its back side to the surface (S0) of the cooling element, where the angle (α₁) between surface (S0) of the cooling element and the window plane (W) is 50-60 degrees. Each LED light source is surrounded by three mainly planar reflecting surfaces (S1, S2, S3) originating close to the surface (S0) of the cooling element adjacent to the LED light source.

[0013] Preferably the angle (α₁) between the surface of the cooling element with the LED light source attached to it and the window plane is 55±1 degrees.

[0014] Preferably the window plane is parallel or inclined maximum of 15 degrees in relation to the street (road, pavement, light traffic road, pedestrian crossing, etc.) to be illuminated.

[0015] The main reflecting surface (S1) of the LED light source has mainly trapezoidal shape, the shorter base of which faces the surface of the cooling element with LED light source and angle (α₂) between one leg of the main reflecting surface and imaginary perpendicular line on the reflecting surface (S1) starting from the shorter base of the trapezium is 2 to 10 degrees.

[0016] An angle (α₃) between second leg of the trapezoidal main reflecting surface (S1) and an imaginary perpendicular line on the reflecting surface (S1) starting from the shorter base of the trapezium is 15 to 25 degrees. An angle (α₄) between said main reflecting surface (S1) and a surface (S0) of the cooling element with LED light source is 100 to 120 degrees.

[0017] In preferred embodiment an angle (α₂) between one leg of the trapezoidal main reflecting surface (S1) of the LED light source and imaginary perpendicular line starting from the shorter base of the trapezium on the reflecting surface (S1) is 5±1 degrees, and an angle (α₃) between the second leg and imaginary perpendicular line starting from the shorter base of the trapezium on reflecting surface (S1) is 22±1 degrees.

[0018] The corresponding legs of the trapezoidal main reflecting surface (S1) are connected to the corresponding edges of the two lateral mainly triangular reflecting surfaces (S2, S3), i.e. accordingly first and second lateral triangular reflecting surface, which are correspondingly at first angle and at second angle to the main reflecting surface (S1) and the corresponding shorter sides of said lateral triangular reflecting surfaces are facing the surface of the cooling element.

[0019] An angle (α₅) between one of the lateral triangular reflecting surfaces (S2) and the trapezoidal main reflecting surface (S1) is 90 to 105 degrees and an angle (α₆) between the second lateral triangular reflecting surface (S3) and the trapezoidal main reflecting surface (S1) is 95 to 115 degrees.

[0020] In a preferred embodiment of the invention, the angle (α₅) between the first lateral triangular reflecting surface (S2) of the LED light source and the trapezoidal main reflecting surface (S1) is at least 90 degrees and the angle (α₆) between the second lateral triangular reflecting surface (S3) and the trapezoidal main reflecting surface (S1) is 110±10 degrees.

[0021] Whereat the edge (h_S2) (i.e. shorter side) of one lateral triangular reflecting surface (S2) facing the cooling element is longer than the edge (h_S3) (i.e. the shorter side) of the second lateral triangular reflecting surface (S3) facing the cooling element.

[0022] Preferably the ratio of the edges (i.e. sides) (h_S3/h_S2) of the first lateral triangular reflecting surface (S2) and the second lateral triangular reflecting surface (S3) facing the LED light source is in the range of 0.50 to 0.80 and even more preferably it would be in the range of 0.65 to 0.70 and most preferably the ratio is approximately 19/28.

[0023] The edge of the second lateral triangular reflecting surface (S3) is connected to the edge of the third mainly planar triangular reflecting surface (S4) having its shortest edge facing the surface of the cooling element.

[0024] These four reflecting surfaces, i.e. the trapezoidal main reflecting surface, the first lateral triangular reflecting surface, the second lateral triangular reflecting surface and the third triangular reflecting surface form a reflector of one LED light source.

[0025] The reflecting surfaces of two adjacent LED light sources on the surface of the cooling element are connected into a single reflector module by a second lateral triangular reflecting surface (S3) of one LED light source, which is connected via second edge of the fourth mainly triangular reflecting surface (S4) to the first lateral triangular reflecting surface (S2) of the adjacent LED light source.

[0026] The cooling element is preferably elongated metal profile with generally trapezoidal or triangular cross-section.

[0027] Preferably the street lighting according to the invention has the COB type LED light sources (COB LED - Chip-on-Board LED - composite LED array having multiple LED chips mounted on a common substrate).

[0028] According to the preferable embodiment of the invention, the street lighting arrange-ment comprises at least one reflector module with two LED light sources.

[0029] According to yet another preferable embodiment of the invention, the street lighting arrangement comprises two reflector modules mirrored on either side of the cooling element with trapezoidal or triangular cross-section.

[0030] According to yet another preferable embodiment of the invention, the street lighting arrangement comprises four reflector modules mirrored in pairs on either side of the cooling element with mainly trapezoidal or triangular cross-section.

Brief description of drawings

[0031] The present invention and different embodiments thereof is hereinafter described with references to the accompanying drawings, wherein:

FIG. 1 depicts the side view of the street lighting arrangement according to the invention installed to a lamppost;

FIG. 2 depicts the side view of the street lighting arrangement according to FIG. 1 in the upwards tilt position;

FIG. 3 depicts the front view of the street lighting arrangement according to FIG. 1 installed to the lamppost;

FIG. 4 depicts schematically a sectional view of the casing of the street lighting arrangement taken along lines A - A of FIG. 1 at the LED light sources;

FIG. 5 depicts schematically in detail sectional view of one reflector module attached to the cooling element;

FIG. 6 depicts schematically the back view of the reflector module, i.e. viewed from the side attached to the cooling element, designed for two LED light sources;

FIG. 7 depicts schematically the front view of the reflector module, i.e. viewed from the side facing away from the cooling element, designed for two LED light sources;

FIG. 8 depicts schematically in detail view of the reflector module designed for two LED light sources, attached to the cooling element with two LED light sources, viewed perpendicular to the window plane;

FIG. 9 depicts the view according to FIG. 8 viewed perpendicular to the surface of the cooling element whereon the LED light sources are attached;

FIG. 10 depicts the embodiment of the street lighting arrangement according to the invention comprising reflector modules mirrored on either side of the cooling element;

FIG. 11 shows a diagram of the distribution of the lighting intensity; and

FIG. 12 depicts a 3D image of the lighting intensity according to FIG. 11.

Description of embodiments

[0032] In the following description of the exemplary embodiments of the invention same parts or elements in different drawings are indicated with the same reference numbers. In the accompanying schematic drawings are omitted for the sake of clarity all parts or elements (e.g. wiring, attachments, etc.) which are not necessary for describing or understanding of the invention.

[0033] FIGs. 1, 2 and 3 depict the street lighting arrangement according to the invention attached to the lamppost. Obviously the street lighting arrangement according to the invention can also be attached to the exterior wall of a building.

[0034] In the positions depicted in FIGs. 1 and 3, the window plane W of the casing 2 of the street lighting arrangement 1 is parallel with the ground. In FIG. 2 the end of the casing 2 of the street lighting arrangement 1 facing away from the lamppost is tilted upwards.

[0035] FIG. 4 depicts schematically a sectional detailed view of the casing 2 of the street lighting arrangement 1 taken along lines A - A of FIG. 1 at the LED light sources 3.

[0036] FIG. 4 shows the symmetrical cooling element 4 with trapezoidal cross-section with the LED light source 3 on each lateral surface S0. In addition, the section shows the reflector module 6 on either side of the cooling element 4. From the both reflector modules 6, FIG. 4 also shows the lateral triangular reflecting surface S2 and the trapezoidal main reflecting surface S1 in the section. As can be seen from FIG. 4, the LED light sources 3 are at an angle to the window plane W. Since the reflector modules on either side of the cooling element 4 have mirror symmetrical shape in relation to the longitudinal direction of the cooling element, below only the reflector module on the one side of the cooling element is described.

[0037] FIG. 5 depicts detail sectional view of one reflector module 6 attached to the cooling element 4. The glass of the casing window can also be seen partially with only the window plane W indicated. The LED light source 3 with its back side is attached to the side surface S0 of the cooling element 4. Since the COB type LED light sources are used in this invention, the side surface S0 of the cooling element 4 is parallel with the plane of the radiating side of the LED light source and all the angles indicated in relation to the side surface S0 of the cooling element 4 are the same also to plane of the radiating side of the LED light source.

[0038] The side surface S0 of the cooling element 4 is at an angle α₁ to the window plane W. In the preferred depicted embodiment the angle α₁ is 55 degrees.

[0039] The LED light source 3 is adjacent to three mainly planar reflecting surfaces beginning closely from the surface S0 of the cooling element 4 beside the LED light source 3 where the main reflecting surface S1 of the LED light source 3 is trapezoidal.

[0040] The LED light source 3 is surrounded by three mainly planar reflecting surfaces originating closely from the surface S0 of the cooling element 4 adjacent to the LED light source 3, where the main reflecting surface S1 of the LED light source 3 is trapezoidal.

[0041] The trapezoidal main reflecting surface S1 is at an angle α₄ to the surface S0 of the cooling element 4 which in the preferred depicted embodiment is 110 degrees.

[0042] As mentioned above, each LED light source 3 is surrounded by three mainly planar reflecting surfaces S1, S2, S3 originating closely from the surface S0 of the cooling element 4 adjacent to the LED light source 3.

[0043] The main reflecting surface S1 of the LED light source has mainly trapezoidal shape, the shorter base of which faces the surface S0 of the cooling element 4 and angle α₂ between one leg of the main reflecting surface and imaginary perpendicular line on the reflecting surface S1 starting from the shorter base of the trapezium is 5 degrees. The angle α₃ between a second leg of the trapezoidal reflecting surface S1 and the imaginary perpendicular line on the reflecting surface S1 starting from the shorter base of the trapezium is 22 degrees; see FIGs. 6 and 7.

[0044] The corresponding legs of the trapezoidal main reflecting surface S1 are connected to the corresponding edges of the two lateral mainly triangular reflecting surfaces S2 and S3, which are correspondingly at first angle α₅ and at second angle α₆ to the main reflecting surface S1. The shorter sides of the lateral triangular reflecting surfaces S2 and S3 are facing the surface S0 of the cooling element 4.

[0045] The angle α₅ between the first lateral triangular reflecting surface S2 and the trapezoidal main reflecting surface S1 is at least 90 degrees. The angle α₆ between the second lateral triangular reflecting surface S3 and the trapezoidal main reflecting surface S1 is at least 110 degrees.

[0046] Whereas the edge h_S2 of the first lateral triangular reflecting surface S2 facing the cooling element 4 is longer than the edge h_S3 of the other lateral triangular reflecting surface S3 facing the cooling element 4.

[0047] The ratio of these edges h_S3/h_S2 is in the range of 0.50 to 0.80 and preferably in the range of 0.65 to 0.70. In the situation depicted in the drawing, this ratio is approximately 19/28.

[0048] FIGs. 8 and 9 show the location of the reflector module 6 in relation to the LED light source 3 installed on surface S0 of the cooling element 4.

[0049] The edge of the second lateral triangular reflecting surface S3 is connected to the fourth mainly triangular and mainly planar reflecting surface S4, the shortest edge of which is facing the surface S0 of the cooling element 4.

[0050] The reflecting surfaces S1, S2 and S3 adjacent to one LED light source 3 and the reflecting surface S4 adjacent to the second reflecting surface S3 form a reflector of a single LED light source.

[0051] The reflector module 6 with two LED light sources 3 is formed on the surface S0 of the cooling element 4 by connecting corresponding edges of the adjacent reflecting surfaces S2 and S4 of the two adjacent LED light sources 3; see FIG. 7.

[0052] A tilt of the reflection surface S4 in relation to the reflecting surfaces S3 and S2 is determined by the ratio of the length h_S3/h_S2 of the shorter edges of the aforesaid second and third lateral reflecting surfaces S2 and S3. In the reflector module with two LED light sources the other reflecting surface S4 which is closer the lateral outer edge of the module and is connected with one of the longer edges with only the reflecting surface S2, has the same tilt as the other reflecting surface S4 of the module which connects two adjacent reflectors.

[0053] There may also be surface S5 on the other edge of the reflector module, which is mainly for the sake of achieving structural rigidness. In the preferred embodiment the reflector module is made of sheet metal.

[0054] FIG. 10 depicts typical embodiment of the street lighting arrangement comprising two reflector modules mounted onto the cooling element and mirrored in shape on either side of the cooling element with trapezoidal or triangular cross-section. For the sake of clarity, only the reflector modules, the LED light sources and the cooling element are depicted.

[0055] In order to understand the scale of the drawings, it should be mentioned that in the case of drawings, that with the COB type LED light source the area of the light diode crystals is of order of 16 mm. The height of the cooling element with trapezoidal cross-section is within the range of 40 mm. The length of one reflector module is within the range of 110 mm and the width approximately 130 mm. These dimensions are indicated as an example only. The dimensions of the reflector module primarily depend on the dimensions and other parameters of the used COB type LED light source.

[0056] FIG. 11 depicts the lighting intensity diagram (units cd/m2) of the lighting arrangement according to invention and corresponding to FIG. 10. During the measurement the lighting arrangement was located at the height of 8 meters from the illuminated surface and the window plane was parallel with the illuminated surface. The lighting arrangement was on one side of the illuminated surface (e.g. road, pavement, etc.) and crosswise with it. As can be seen from the diagram, the beam pattern on the illuminated surface is relatively even.

[0057] FIG. 12 shows a 3D image of the lighting intensity according to FIG. 11, where the position of the lighting arrangement 1 according to the invention is shown schematically in relation to the illuminated surface. The grey shades of the light spot in FIG. 12 do not correspond one-to-one to the lighting intensity (brightness) but these grey shades have emerged at the conversion into black and white image of the originally colour diagram, where the intensity is depicted towards the decrease of the intensity from red to violet.

[0058] It is obvious for the person skilled in the art that present invention is not limited to the embodiment described above and depicted in the drawings but also other embodiments are possible within the limits of the accompanying claim.

Claims

1. A street lighting arrangement comprising in a casing with a planar window at least one LED light source, at least one reflector of the LED light source, at least one cooling element, and where each LED light source and each reflecting surface is at an angle in relation to the plane of the window, characterized in that in the street lighting arrangement each LED light source is attached by its back side to the surface (S0) of the cooling element, where the angle (α₁) between surface (S0) of the cooling element and the window plane (W) is 50-60 degrees, where each LED light source is surrounded by three mainly planar reflecting surfaces (S1, S2, S3) originating close to the surface (S0) of the cooling element adjacent to the LED light source, where the main reflecting surface (S1) of the LED light source has mainly trapezoidal shape, the shorter base of which faces the surface of the cooling element with LED light source and angle (α₂) between one leg of the trapezium and imaginary perpendicular line on said main reflecting surface (S1) starting from the shorter base of the trapezium is 2 to 10 degrees, and where an angle (α₃) between second leg of the trapezium and an imaginary perpendicular line on the main reflecting surface (S1) starting from the shorter base of the trapezium is 15 to 25 degrees, and where an angle (α₄) between said main reflecting surface (S1) and a surface (S0) of the cooling element with LED light source is 100 to 120 degrees; where the corresponding legs of the trapezoidal main reflecting surface (S1) are connected to the corresponding edges of the two lateral mainly triangular reflecting surfaces (S2, S3), which are correspondingly at first angle and at second angle to the main reflecting surface (S1), and where the shorter sides of said two lateral triangular reflecting surfaces (S2, S3) are facing the surface (S0) of the cooling element; where an angle (α₅) between first lateral triangular reflecting surface (S2) and the trapezoidal main reflecting surface (S1) is 90 to 105 degrees and an angle (α₆) between the second lateral triangular reflecting surface (S3) and the trapezoidal main reflecting surface (S1) is 95 to 115 degrees, and the edge (h_S2) of first lateral triangular reflecting surface (S2) facing the cooling element is longer than the edge (h_S3) of the second lateral triangular reflecting surface (S3) facing the cooling element; where the edge of the second lateral triangular reflecting surface (S3) is connected to the edge of the fourth mainly planar triangular reflecting surface (S4) having its shortest edge facing the surface of the cooling element; where the reflecting surfaces of two adjacent LED light sources on the surface of the cooling element are connected into a single reflector module by a second lateral triangular reflecting surface (S3) of one LED light source, which is connected via second edge of the fourth mainly triangular reflecting surface (S4) to the first lateral triangular reflecting surface (S2) of the adjacent LED light source.

2. The street lighting arrangement according to claim 1, characterized in that the angle (α₁) between the window plane (W) and the surface of the cooling element with the LED light source attached is 55±1 degrees.

3. The street lighting arrangement according to any one of the preceding claims, characterized in that the angle (α₂) between one leg of the trapezium of trapezoidal main reflecting surface (S1) of the LED light source and imaginary perpendicular line starting from the shorter base of the trapezium on the reflecting surface (S1) is 5±1 degrees, and the angle (α₃) between the second leg of trapezium of said trapezoidal main reflecting surface (S1) and imaginary perpendicular line starting from the shorter base of the trapezium on said reflecting surface (S1) is 22±1 degrees.

4. The street lighting arrangement according to any one of the preceding claims, characterized in that the angle (α₄) between said main reflecting surface (S1) and the surface (S0) of the cooling element with LED light source is 110±1 degrees.

5. The street lighting arrangement according to any one of the preceding claims, characterized in that the angle (α₅) between the first lateral triangular reflecting surface (S2) of the LED light source and the trapezoidal main reflecting surface (S1) is at least 90 degrees and the angle (α₆) between the second lateral triangular reflecting surface (S3) and the trapezoidal main reflecting surface (S1) is 110±10 degrees.

6. The street lighting arrangement according to any one of the preceding claims, characterized in that the ratio (h_S3/h_S2) of the edges of the first lateral triangular reflecting surface (S2) and the second lateral triangular reflecting surface (S3) facing the LED light source is in the range of 0.50 to 0.80.

7. The street lighting arrangement according to any one of the preceding claims 1 to 5, characterizedin that the ratio (h_S3/h_S2) of the edges of the first lateral triangular reflecting surface (S2) and the second lateral triangular reflecting surface (S3) facing the LED light source is in the range of 0.65 to 0.70.

8. The street lighting arrangement according to any one of the preceding claims 1 to 5, characterized in that the ratio (h_S3/h_S2) of the edges of the first lateral triangular reflecting surface (S2) and the second lateral triangular reflecting surface (S3) facing the LED light source is 19/28.

9. The street lighting arrangement according to any one of the preceding claims, characterized in that the LED light source is the COB-type LED light source.

10. The street lighting arrangement according to any one of the preceding claims, characterized in that it comprises two reflector modules mirrored on either side of the cooling element with trapezoidal cross-section.

11. The street lighting arrangement according to any one of the preceding claims 1 to 9, characterized in that it comprises at least one reflector module with two LED light sources.

Drawing