Twisted downlight reflectors

Abstract

A generic reflector comprises a light inlet end, a light outlet end with at least one substantially rectangular light outlet opening, an optical axis, and a reflector surface which extends between the light inlet end and the light outlet end, where the reflector surface in a plane perpendicular to the optical axis defines a polygon. The reflector surface is formed such that the polygon between the light inlet end and the light outlet end at least in sections rotates about an axis of rotation which is oriented parallel to the optical axis. The invention also relates to an arrangement comprising at least two reflectors and a luminaire with a reflector and a light source, comprising an LED.

Claims

1. A reflector for a luminaire, in particular for a luminaire with at least one LED light source, comprising a light inlet end, a light outlet end with at least one substantially rectangular light outlet opening, an optical axis, and a reflector surface which extends between said light inlet end and said light outlet end, where said reflector surface at least in sections in a plane perpendicular to said optical axis defines a polygon, wherein said reflector surface is formed such that said polygon between said light inlet end and said light outlet end at least in sections rotates about an axis of rotation which is oriented parallel to said optical axis, wherein said reflector is flattened at said light inlet end and said reflector surface at said flattened light inlet end opens to a base area, and wherein said light outlet opening and said base area are formed substantially square-shaped, and said polygon is a point-symmetrical octagon with a 4-fold rotational symmetry, where said reflector surface is designed such that it extends parabolically in a plane parallel to said optical axis between said light inlet end and said light outlet end, and said polygon rotates between said base area and said light outlet opening along said entire reflector surface such that the corners of said base area transition to those corners of the octagon which open to the centers of said edges of said light outlet opening, and the centers of said edges of said base area transition to those corners of said octagon which open to the corners of said light outlet opening.

2. The reflector according to claim 1, wherein the edges of said polygon are formed in a curved manner.

3. The reflector according to claim 1, wherein said polygon is point-symmetric and the center of symmetry is located on said axis of rotation.

4. The reflector according to claim 3, wherein said polygon is a point-symmetrical octagon with a 4-fold rotational symmetry.

5. The reflector according to claim 1, wherein said polygon rotates along said entire reflector surface between said light inlet end and said light outlet end.

6. The reflector according to claim 1, wherein said rotational angle swept through by a corner of said polygon in a plane perpendicular to said axis of rotation due to the rotation between said light inlet end and said light outlet end is greater than 15.degree.

7. The reflector according to claim 1, wherein said rotational angle of each corner is substantially 360.degree. divided by the number of corners of said polygon.

8. The reflector according to claim 1, wherein said reflector surface is formed in a parabolic manner in a plane parallel to said optical axis between said light inlet end and said light outlet end.

9. The reflector according to claim 1, wherein said reflector comprises a light inlet opening at said light inlet end.

10. The reflector according to claim 1, wherein said base area is formed to be substantially rectangular, and a second transition region is formed at said light inlet end in which said polygon transitions continuously to the shape of said base area.

11. The reflector according to claim 1, wherein said reflector is produced by way of injection-molding.

12. An arrangement comprising at least two reflectors according to claim 1, wherein said light outlet openings of said reflectors are disposed adjacently and the rotations of said polygons of adjacent reflectors have an opposite direction of rotation.

13. A luminaire with a reflector and a light source, wherein said reflector is formed according to claim 1, and said light source is disposed at said light outlet opening of said reflector and comprises at least one LED.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An embodiment of the present invention is explained in more detail below with reference to drawings, where:

(2) FIG. 1: shows a schematic representation of a reflector according to the invention in perspective,

(3) FIG. 2: shows a further representation of the reflector of FIG. 1 in perspective,

(4) FIG. 3: shows the reflector of FIG. 1 in cross section along section line A,

(5) FIG. 4: shows the reflector of FIG. 3 in cross section along section line B,

(6) FIG. 5: shows the reflector of FIG. 3 in cross section along section line C,

(7) FIG. 6: shows the reflector of FIG. 3 in cross section along section line D.

(8) FIG. 7: shows the reflector of FIG. 3 in cross section along section line E,

(9) FIG. 8: shows an arrangement of four reflectors according to the invention in perspective and

(10) FIG. 9: shows a further representation of the arrangement in FIG. 8 in perspective.

DETAILED DESCRIPTION

(11) It applies for the following explanations same components are denoted by same reference numerals in the event that a drawing contains reference numerals which are not explained in more detail in the accompanying figure description, then reference is made to preceding or subsequent figure descriptions.

(12) FIGS. 1 and 2 show a reflector 1 according to the invention with a light inlet end 2, a light outlet end 3 and a reflector shell 7 which extends between light inlet end 2 and light outlet end 3. A light outlet opening 6 is formed at light outlet end 3. Reflector surface 4 is formed on the inner side of reflector shell 7. The reflector comprises a flattened light inlet end 2 with a base area 8. Base area 8 is square, where the edges are formed in a convex manner. A light inlet opening 5 is formed at base area 8. Reflector surface 4 surrounds optical axis O of reflector 1. In the embodiment illustrated, light inlet opening 5 and light outlet opening 6 are formed to be square and are oriented to be coaxial relative to optical axis O and parallel to each other.

(13) Reflector 1 was produced by way of an injection-molding process, where a reflector body comprising reflector shell 7 is first produced and reflector surface 4 is then applied as a reflective coating on the inner side of reflector shell 7. In order to facilitate demolding of reflector 1 during injection-molding, the outer side of reflector shell 7 is formed to be convex. The outer side there follows the curvature of reflector surface 4, so that reflector shell 7 has a substantially uniform wall thickness.

(14) It is in FIG. 2 shown that reflector surface 4 defines an octagon. Reflector surface 4 at light outlet end 3 comprises a first transition region 12, and at light inlet end 3 a second transition region 13. In transition regions 12, 13, octagon 11 transitions continuously to the shape of light inlet opening 5 or light outlet opening 6, respectively. Octagon 11 rotates along the entire reflector surface 4 between light inlet end 2 and light outlet end 3 about an axis of rotation R, where axis of rotation R coincides with optical axis O. Octagon 11 also rotates within first transition region 12 and second transition region 13. The edges of rotating octagon 11 define spirals 9, 10 on reflector shell 7 and on reflector surface 4. In the illustrated embodiment, the entire angel of rotation of all corners α is 45°. The angle of rotation of each corner is therefore greater than 15° and corresponds to 360° divided by the number of corners.

(15) Spirals 9 each extend from a center of the edges of base area 8 to a respective corner of light outlet opening 6. Spirals 10 each extend from a corner of base area 8 to a respective center of the edges of light outlet opening 6.

(16) FIG. 3 shows the reflector of FIG. 1 in cross section along section line A. Reflector surface 4 is in the embodiment shown formed in a parabolic manner. Base area 8 and light outlet opening 6 are parallel to each other.

(17) FIG. 4 shows second transition region 13 of reflector 1 of FIG. 3 in a sectional view along axis B. Octagon 11 has almost completely transitioned to the shape of base area 8, and in relation to base area 8 has a small rotational angle α of about 5° about axis of rotation R.

(18) FIG. 5 shows the reflector of FIG. 3 along section line C. Polygon 11 being defined by reflector surface 4 is a point-symmetrical octagon 11 with a 4-fold rotational symmetry rotating about its center of symmetry. The edges of octagon 11 are formed in a convex manner.

(19) FIG. 6 shows the reflector of FIG. 3 along section line D. Octagon 11 is further point-symmetrical and has a 4-fold rotational symmetry. However, it has slightly changed the shape of octagon 11 since the corners defining spirals 9 for reaching the corners of light outlet opening 5 must travel a greater distance than the corners defining spirals 10. The rotational angle α is now about 30°.

(20) FIG. 7 shows first transition region 12 of the reflector of FIG. 3 along section line E. Octagon 11 further rotates and has almost entirely transitioned to the shape of the light outlet opening. The rotational angle α is now about 45°.

(21) FIGS. 8 and 9 show an arrangement 14 of 4 reflectors 1, 15, where reflectors 15 correspond to the reflector of FIGS. 1-7, but have an opposite direction of rotation. The 4 light inlet ducks 3 [sic] are located adjacently in one plane.