WO2012049104A2

WO2012049104A2 - Reflector and luminaire comprising the reflector

Info

Publication number: WO2012049104A2
Application number: PCT/EP2011/067616
Authority: WO
Inventors: Canbang Yang; Aiai Li; Yabin Luo; Haiping Yuan
Original assignee: Osram Ag
Priority date: 2010-10-11
Filing date: 2011-10-10
Publication date: 2012-04-19
Also published as: CN102444863A; CN102444863B; WO2012049104A3

Abstract

The present invention relates to a reflector configured for a light source, comprising at least one reflector unit (1), characterized in that each reflector unit (1) comprises: a base (5) configured to hold light source (4), a first reflecting body (2) and a second reflecting body (3) at two opposite sides of the light source (4) and extending in a light exit direction, and the first reflecting body (2) is formed with a first reflecting face (A) at a side facing the light source, the second reflecting body (3) is formed with a second reflecting face (B) at a side facing the light source, and the first and the second reflecting faces (A, B) are asymmetrical and can generate an oval light distribution pattern. The reflector according to the present invention can realize an oval light distribution pattern in a reflective manner whose center offset from an optical axis, achieves high optical efficiency, good uniformity of light distribution and good light cut-off effect, and also has advantages such as convenient mounting, low cost and small size.

Description

Reflector And Luminaire Comprising the Reflector

Technical Field

The present invention relates to a reflector and a luminaire comprising the same. Background Art

For modern street lighting, in some situations, the center of an oval light distribution pattern needs to offset from an optical axis. In the lighting devices in the prior art, to realize an oval light distribution pattern offset from an optical axis, some additional lenses are needed for a second light distribution. The above light distribution pattern offset from the optical axis is realized by designing the lens to be non-rotational asymmetrical. This solution has the following disadvantages: first, as one additional lens is needed, the assembling of the lighting device will be complex and then leads to high cost. In addition, the mounting of the lighting device occupies a relatively large space. Second, as the material of the lens is PMMA or PC, the lives of such plastics will be relatively low. Third, large light loss is incurred due to the refraction of the lens.

Summary of the Invention

The object of the present invention is to provide a non-rotational asymmetrical reflector for a light source, and the reflector replaces a secondary lens in the prior art which realizes an oval light distribution pattern whose center offset from an optical axis, and an oval light distribution pattern whose center offset from an optical axis is realized in a reflective manner. As the secondary lens is not needed, the disadvantages of the secondary lens in the prior art will not exist.

The present invention provides a reflector for a light source, comprising at least one reflector unit, characterized in that each reflector unit comprises: a base configured to hold a light source, a first reflecting body and a second reflecting body at two sides of the light source and extending in a light exit direction, and the first reflecting body is formed with a first reflecting face at a side facing the light source, the second reflecting body is formed with a second reflecting face at a side facing the light source, and the first and the second reflecting faces are asymmetrical and can generate an oval light distribution pattern. The above light distribution pattern is realized via the asymmetrical design of the first reflecting face and the second reflecting face.

The concept of the present invention is to abandon the rotational symmetrical reflector plus a secondary lens. Instead of this, the present invention consider directly realizing a light distribution pattern whose center offset from an optical axis in a reflective manner by providing a first reflecting face and a second reflecting face which are asymmetrical and can generate an oval light distribution pattern. As the light is emitted after they are reflected by the first reflecting face and the second reflecting face light, loss can be minimized and optical efficiency can be improved. Compared with the prior art, the present invention, without the second light distribution of the lens, realizes the desired light pattern in a reflective manner and achieves good optical efficiency.

It needs to be pointed out that the lengths, the widths, the design of the profile and etc. of the first reflecting face and the second reflecting face, are obtained by calculating optical paths considering the light distribution pattern to be achieved, considering such as the best optical efficiency. For example, the first reflecting face should be designed to lower the possibility of second reflection to realize high optical efficiency. Preferably, the first and the second reflecting faces are formed by curve surfaces or straight line faces. Alternatively, the first and the second reflecting faces can also be formed by spline curves. Another replaceable preferable solution is that the first reflecting face is sequentially formed by a concave arc face and a plane in the light exit direction, and the second reflecting face is sequentially formed by a convex arc face and a plane in the light exit direction, thereby realizing a high optical efficiency.

The ratio of the length of plane to the concave round arc face in the light exit direction is 1 .2-1 .4, preferably 1 .28 and the radius of concave circular arc face is 15mm-20mm, preferably 18.18 mm, that the ratio of the length of plane to the convex arc face in the light exit direction is 0.6-0.8, preferably 0.7 and the radius of convex circular arc face is 25mm-35mm .preferably 29.76 mm.

According to an improved solution of the present invention, each reflector unit further comprises two third reflecting faces respectively extending from the second reflecting face towards the central light source. The third reflecting face can be a plane or an arc face, preferably a concave arc shape. The third reflecting face can improve the uniformity of light distribution and increase the beam angle of the oval light distribution pattern in a long axis direction. In the case that the third reflecting face is in a concave arc shape, the radian of the concave arc of the third reflecting face is determined in consideration of a beam angle of the oval light distribution pattern in a long axis direction and light uniformity. Preferably, the two third reflecting faces are symmetrical and converge together. Preferably, the radius of circular arc of third reflecting face is 8-12mm, more preferably 10.1 mm.

According to another improved solution of the present invention, each reflector unit further comprises two fourth reflecting faces at another two sides of the light source, and each of the fourth reflecting face is designed to be a plane and extends at an inclination angle with respect to the bottom surface. That is, in two opposite sides of the four sides around the light source, the first reflecting face and the second reflecting face are provided, and the fourth reflecting faces are provided in the other two opposite sides. According to relevant State regulations, some roads require cut-off luminaires to ensure that the glare effect due to the road luminaires is within a reasonable and secure range. Hence, the design of the fourth reflecting face can meet the above relevant regulations. The inclination angle of the fourth reflecting face can also affect the light shape and the uniformity of the light. Preferably, the inclination angle is 65°-70°, more preferably 67°. In addition, the height of the fourth reflecting face relating to the center of the light source is designed such that the angle of the line between the center of the light source and the top of the fourth reflecting face relating to horizon is 10° to 20°, preferably, 15°.

According to another improved solution of the present invention, the reflector unit is formed integrally. Thus, the production cost is greatly lowered and the process complexity is simplified.

The non-rotational symmetrical reflector according to the present invention and a luminaire comprising the reflector can realize in a reflective manner an oval light distribution pattern whose center offset from an optical axis, achieves high optical efficiency, good uniformity of light distribution and good light cut-off effect, and also has advantages such as convenient mounting, low cost and small size.

Brief Description of the Accompanying Drawings

The preferable embodiments according to the present invention are illustratively described hereinafter with reference to the accompanying drawings. As shown in the drawings:

Figure 1 is a front sectional view of a reflector unit of the reflector according to the present invention; Figure 2 is a top sectional view of a reflector unit of the reflector according to the present invention;

Figure 3 is a perspective view of a reflector unit of the reflector according to the present invention;

Figures 4a, 4b and 4c illustrate enlarged views of first, second and third reflecting curve surfaces of a reflector unit of the reflector according to the embodiment of the present invention;

Figure 5 is a schematic view of the reflector according to the present invention arranged by multiple reflector units in an array manner; and

Figure 6 illustrates the light distribution of the reflector according to the present invention.

Detailed Description of the Invention

Figure 1 is a front sectional view of a reflector unit 1 of the reflector according to the present invention. The reflector unit 1 comprises: a base 5, an opening 6 provided in the base 5 for holding a light source 4 (as shown in Figure 5); and a first reflecting body 2 and a second reflecting body 3 are respectively provided at the right and the left sides of the opening 6 and extend in a light exit direction. The two reflecting bodies 2, 3 are provided in a direction substantially parallel to an optical axis. The first reflecting body 2 is formed with a first reflecting face A at a side facing the light source, the second reflecting body 3 is formed with a second reflecting face B at a side facing the light source, and the two reflecting faces A, B are designed asymmetrical. According to the embodiment shown in Figure 1 , the first reflecting face A and the second reflecting face B are both formed by spline curves. In the embodiment according to Figure 4a, the first reflecting face A sequentially includes a concave circular arc segment A1 and a straight line segment A2 in the light exit direction (see Figure 4a). The second reflecting face B includes a straight line segment B1 and a convex circular arc segment B2. The proportion of A1/A2 or B1/B2 in length, the radius of the concave circular arc segment A1 , the radius of convex circular arc segment B2 can be determined by calculating optical paths considering the light distribution pattern to be achieved, considering such as the best optical efficiency etc. The ratio of the length of plane A2 to the concave round arc face A1 in the light exit direction is 1.2-1 .4 preferably 1 .28 and the radius of concave circular arc face A1 is 15mm-20mm, preferably 18.18 mm. The ratio of the length of plane B1 to the convex arc face B2 in the light exit direction is 0.6-0.8, preferably 0.7and the radius of convex circular arc face B2 is 25mm-35mm .preferably 29.76 mm.

The first and the second reflecting faces A, B are designed such that they can generate the oval light distribution pattern and can lower second reflection on the reflecting faces A, B to realize high optical efficiency. Also, two third reflecting faces C (see Figure 5b) respectively extend from the front and the rear sides of the second reflecting face B towards a central light source, and fourth reflecting faces D (see Figure 2 and Figure 5c) for light cut-off are provided at the front and the rear sides (only the rear side 7 is shown in the figure 1 ) of the opening 6. The inclination angle of the fourth reflecting face D can also affect the light shape and the uniformity of the light, and preferably, the inclination angle is 65°-70°, preferably 67°. In addition, the height of the fourth reflecting face D is designed such that the angle of line connecting the center of the light source and the top of the fourth reflecting face relating to horizontal is 10° to 20°, preferably, 15°.

Figure 2 is a top sectional view of a reflector unit 1 of the reflector according to the present invention. Figure 3 is a perspective view of a reflector unit 1 of the reflector according to the present invention. As seen from the combination of Figures 2 and 3, two third reflecting faces C respectively extend from positions close to the front and the rear sides of the second reflecting face B towards a central light source 4 in an arc shape. The two third reflecting faces finally converge together. The radius of circular arc of third reflecting face is 8-12mm, more preferably 10.1 mm. The third reflecting faces C can also be designed to improve the uniformity of light distribution and increase a beam angle of the oval light distribution pattern in a long axis direction. The radian of the third reflecting face C is determined according to the range of a preset beam angle in a long axis direction and light uniformity. Of course, the third reflecting face can also be in a planar shape rather than the arc shape. Figure 5 is a schematic view of the reflector arranged by multiple reflector units in an array manner. The reflector according to the present invention can realize a beam angle of 150°^*40°at the oval light distribution pattern (see Figure 6), and the optical efficiency can be as high as 91 %, and the light cut-off effect can be 416cd/k1 m at 70°, 5cd\klm at 80°, and 0.28cd\klm at 90°.

Reference signs:

1 reflector unit

2 first reflecting body

3 second reflecting body 4 light source

5 base

6 opening

7 rear side

A first reflecting face B second reflecting face C third reflecting face D fourth reflecting face

Claims

Claims:

1 . A reflector for a light source, comprising at least one reflector unit (1 ), characterized in that each reflector unit (1 ) comprises: a base (5) configured to hold a light source (4), a first reflecting body (2) and a second reflecting body (3) at two sides of the light source (4) and extending in a light exit direction, and the first reflecting body (2) is formed with a first reflecting face (A) at a side facing the light source, the second reflecting body (3) is formed with a second reflecting face (B) at a side facing the light source, and the first and the second reflecting faces (A, B) are asymmetrical and can generate an oval light distribution pattern.

2. The reflector according to claim 1 , characterized in that the first and the second reflecting faces (A, B) are formed by curve surfaces.

3. The reflector according to claim 1 , characterized in that the first and the second reflecting faces (A, B) are formed by spline curves.

4. The reflector according to claim 1 , characterized in that the first reflecting face (A) is sequentially formed by a concave arc face (A1 ) and a plane (A2) in the light exit direction, and the second reflecting face (B) is sequentially formed by a convex arc face (B2) and a plane (B1 ) in the light exit direction.

5. The reflector according to claim 4, characterized in that the ratio of the length of plane (A2) to the concave round arc face (A1 ) in the light exit direction is 1 .2-1.4 and the radius of concave circular arc face (A1 ) is 15mm-20mm, that the ratio of the length of plane (B1 ) to the convex arc face (B2) in the light exit direction is 0.6-0.8 and the radius of convex circular arc face (B2) is 25mm-35mm.

6. The reflector according to claim 1 , characterized in that each reflector unit (1 ) further comprises two third reflecting faces (C) respectively extending from the second reflecting face (B) towards the central light source (4).

7. The reflector according to claim 6, characterized in that the third reflecting face (C) is in a concave circular arc shape.

8. The reflector according to claim 7, characterized in that the radius of circular arc of third reflecting face (C) is 8-12mm.

9. The reflector according to claim 7, characterized in that the two third reflecting faces (C) are symmetrical and converge together.

10. The reflector according to claim 1 , characterized in that each reflector unit (1 ) further comprises two fourth reflecting faces (D) at another two sides of the light source (4), and each of the fourth reflecting face (D) is designed to be a plane and extends at an inclination angle with respect to the base(5).

11 . The reflector according to claim 10, characterized in that the inclination angle of the fourth reflecting face (D) is 65°-70°.

12. The reflector according to claim 10, characterized in that the height of the fourth reflecting face (D) relating to the center of the light source is designed such that the angle of the line between the center of the light source and the top of the fourth reflecting face relating to horizon is 10° to 20°.

13. The reflector according to claim 1 , characterized in that the reflector unit (1 ) is formed integrally.

14. A Luminaire comprising the reflector according to any one of claims 1 -13.