EP3098504B1 - Twisted deep radiator reflectors - Google Patents

Description

The present invention relates to a reflector for a luminaire, in particular for a luminaire with at least one LED light source, according to the preamble of claim 1. Accordingly, a generic reflector comprises a light entry end, a light exit end with at least one substantially quadrangular light exit opening, an optical axis, and a reflector surface extending between the light entrance end and the light exit end, the reflector surface defining a polygon in a plane perpendicular to the optical axis.

Generic reflectors come u.a. in recessed spotlights, but also in other lights used. Usually, the light exit opening is aligned concentrically to the optical axis of the reflector, and the optical axis is substantially completely surrounded by the reflector surface. In particular, reflectors with a rectangular reflector surface are often used, wherein the four side surfaces of the reflector in the direction between the light entry end and the light exit end are curved in particular parabolic.

A disadvantage of the generic reflectors, however, is that the reflector surface at the corners of the cross-sectional area is not continuous into one another. In generic reflectors, the angle between the faces of the reflector surface is 90 °. This leads to inhomogeneities of the illuminance in the emitted cone of light. Ideally, the emitted light cone has a light intensity with sharp edges, wherein the shape of the light cone substantially corresponds to the shape of the reflector surface, if no aperture is arranged at the light exit end of the reflector or in the direction of the emitted light cone. The inhomogeneities caused by the edges now cause the emitted light cone not a uniform illuminance, but areas with increased or decreased illuminance.

These disadvantages are particularly evident in LEDs as light sources, because with the use of these quasi point-shaped light sources, the imaging properties of the reflectors have stronger effects on the emitted light beam. Therefore, generic reflectors have particularly strong inhomogeneities when used with LEDs.

From the DE 699 353 81 D2 is a luminaire with faceted reflector and spiral lens known. The reflector has a circular light exit opening and a reflector surface which shows a regular 48-sided polygon.

Furthermore, the describes EP 0915 287 A2 a round reflector, wherein the reflector is provided inside with spirally formed reflector surfaces. As the light source, a light bulb is used.

The US 7,441,927 discloses a lamp with individual facets extending spirally from the light entrance opening to the light exit opening. A corresponding lamp is particularly suitable for the use of halogen lamps.

It is therefore an object of the present invention to provide a reflector of the type mentioned, whose radiated light cone has a more homogeneous illuminance.

The object is achieved by the features of claim 1. Accordingly, in a reflector of the type mentioned above, an inventive solution to the problem, if the reflector surface is formed such that the polygon between the light entry end and the light exit end at least partially rotated about an axis of rotation , which is aligned parallel to the optical axis.

The invention offers the advantage that a twisted surface of revolution is created by the rotating polygon. The inhomogeneities generated along the edge are thus no longer superimposed in one area of the emitted cone of light, but are distributed over several emission directions and are superimposed by light beams which have been reflected off the edges of the reflector surface. The luminous intensity of the emitted light cone becomes more homogeneous overall.

As reflectors usually taper toward the light entry end, it is obviously possible within the scope of the present invention that the polygon also changes shape and size between the light entry end and the light exit end. The corners of the rotating polygon define spirals on the reflector surface.

In one embodiment, the polygon has more than four corners, and at the light exit end, a first transition region is formed, in which the polygon merges continuously into the shape of the light exit opening. Increasing the number of corners increases the angle between two adjoining surface sections, resulting in a reduction in the inhomogeneity of a corner. In the first transition region, the polygon can continue to rotate about the rotation axis.

Since the optical axis and the axis of rotation are parallel, and the plane of the polygon is perpendicular to the optical axis, the axis of rotation is also perpendicular to the plane of the polygon.

In one embodiment of the present invention, the reflector surface is a reflective coating of a reflector shell. It is also an alternative possible that the reflector shell consists of a reflective material and its inner, the optical axis facing surface is formed as a reflector surface.

In a further embodiment of the present invention, the axis of rotation and the optical axis coincide. This makes it possible to realize symmetrical light cone shapes in a particularly simple manner. However, it is alternatively conceivable that the rotational axis and the optical axis do not coincide for the realization of other light cone shapes.

In a further embodiment of the reflector according to the invention, the light exit opening is square. However, it is alternatively also conceivable that the light exit opening has a different quadrangular shape.

In the context of the present invention, the quadrangular light exit opening may have curved edges. This allows the reflector to adapt to lighting tasks or design aspects.

The present invention further provides an arrangement with at least two reflectors according to the invention, wherein the light exit openings of the reflectors are arranged adjacent, and the rotations of the polygons of adjacent reflectors have an opposite direction of rotation.

The invention further provides a luminaire with a reflector according to the invention and a light source, wherein the light source is arranged at the light entry end of the reflector and comprises at least one LED. The reflector according to the invention is particularly advantageous for lights with LEDs.

Advantageous embodiments of the present invention are the subject of the dependent claims.

In a preferred embodiment, the edges of the polygon are curved. As a result, the reflector can be easily adapted to lighting tasks. In particular, the edges are convexly curved. This further improves the imaging properties of the reflector. In this embodiment, the outside of the reflector shell may be curved in particular convex.

In a further preferred embodiment, the polygon is a point-symmetric polygon, and the center of symmetry lies on the axis of rotation. Accordingly, the polygon rotates about its center of symmetry. This makes it particularly easy to realize symmetrical light cone shapes.

According to the invention, the polygon is a point-symmetrical octagon with a 4-fold rotational symmetry. In this embodiment, even a small angle of rotation already has a particularly advantageous effect on the homogeneity of the illuminance, while at the same time the production costs and the number of discontinuities in the reflector surface are kept low.

Most preferably, four of the eight corners of the octagon open at the corners of the quadrangle of the light exit opening, and the remaining four corners of the octagon at the midpoints of the edges of the quadrangle of the light exit opening, with the corners of the octagon alternately at the corners and at the centers of the edges the light exit opening open.

According to the invention, the polygon rotates along the entire reflector surface between the light entry end and the light exit end. In this embodiment, the rotation of the polygon has a particularly effective effect on the homogeneity of the illuminance of the emitted light cone. If the reflector has a first transition region at the light exit end, the polygon can rotate to the beginning of the transition region or even within the transition region to the light exit end.

In a further preferred embodiment, the angle of rotation swept from a corner of the polygon in a plane perpendicular to the axis of rotation by the rotation between the light entry end and the light exit end is greater than 15 °. From this angle of rotation, the rotation has a particularly advantageous effect on the homogeneity of the illuminance.

In another preferred embodiment, the angle of rotation of each corner is substantially 360 ° divided by the number of corners of the polygon. In this embodiment, the inhomogeneities of a corner are distributed over an area that extends to the starting point of the inhomogeneity caused by the next corner. At this angle of rotation so no inhomogeneities are available.

According to the invention, the reflector surface is parabolic in a plane parallel to the optical axis between the light entry end and the light exit end. In this embodiment, the reflector additionally has the refractive properties of a parabolic mirror. In this embodiment, it is particularly easy to realize parallel light cones.

In a further preferred embodiment, the reflector has a light inlet opening at the light entry end. Through the light entrance opening, a light source can be arranged in a particularly simple manner in the reflector, or introduce light in a particularly simple way in the reflector.

According to the invention, the reflector is flattened at the light entry end and the reflector surface opens at the flattened light entry end into a base surface. This makes the reflector very compact. The base surface formed by the flattened end, into which the reflector surface opens, can have the shape of the polygon. Most preferably, the base and the plane spanned by the light exit opening are parallel.

In a further very particularly preferred embodiment, the base surface is formed substantially quadrangular, and at the light entry end, a second transition region is formed, in which the polygon merges steadily into the shape of the base surface. As a result, inhomogeneities generated in the emitted light cone are avoided by edges. In particular, the shape of the base surface may have curved edges and / or the shape of the light exit opening. This results in a particularly aesthetic overall impression. In this embodiment, the polygon in the second transition region can continue to rotate about the axis of rotation.

According to the invention, the light exit opening and the base area are essentially square, and the polygon is a point-symmetrical octagon with a 4-fold rotational symmetry, wherein the reflector surface is designed to be parabolic in a plane parallel to the optical axis between the light entry end and the light exit end runs and the polygon between the base and the light exit opening along the entire reflector surface rotates such that the corners of the base pass into those corners of the octagon, which open at the centers of the edges of the light exit opening, and the centers of the edges the base surface in those corners of the octagon, which open in the corners of the light exit opening. This design results in an improved illuminance regardless of the height of the reflector. In addition, there is a good overall aesthetic impression.

In this embodiment, two different spiral shapes are defined on the reflector surface by the corners of the rotating octagon, with the first spirals extending from the centers of the corners of the base to the centers of the edges of the light exit aperture and the second spirals from the centers of the edges of the base extend the corners of the light exit opening.

In a particularly preferred embodiment, the edges of the base surface and the edges of the light exit opening are aligned parallel to each other. This results in a particularly aesthetic reflector.

In a further preferred embodiment, the reflector is produced by means of injection molding. Thus, the reflector according to the invention can be produced particularly easily.

In a particularly preferred embodiment, the reflector shell is at least partially convex. As a result, the demolding of the reflector during injection molding is simplified.

Most preferably, a reflector body is first produced by means of injection molding and then applied to the inside of the reflector shell to form the reflector surface, a reflective layer. With this method, the reflector according to the invention can be produced in a particularly simple and cost-effective manner.

In a particularly preferred arrangement, the arrangement comprises four reflectors, which are arranged in a rectangle, wherein the opposite reflectors are of the same design. The superposition of the invention homogeneous light cone of the individual reflectors results in a particularly homogeneous emitted light beam for the entire arrangement.

In a preferred embodiment of the luminaire, the luminaire comprises a diffuser element. The diffuser element can be designed, for example, as a cover glass be and be arranged at the light exit opening. As a result, the illuminance of the emitted light cone can be further homogenized.

Figur 1:

eine schematische Darstellung eines erfindungsgemäßen Reflektors in Perspektive,

Figur 2:

eine weitere Darstellung des Reflektors der Fig. 1 in Perspektive,

Figur 3:

den Reflektor der Fig. 1 im Querschnitt entlang der Schnittlinie A,

Figur 4:

den Reflektor der Fig. 3 im Querschnitt entlang der Schnittlinie B,

Figur 5:

den Reflektor der Fig. 3 im Querschnitt entlang der Schnittlinie C,

Figur 6:

den Reflektor der Fig. 3 im Querschnitt entlang der Schnittlinie D,

Figur 7:

den Reflektor der Fig. 3 im Querschnitt entlang der Schnittlinie E,

Figur 8:

eine Anordnung von vier erfindungsgemäßen Reflektoren in Perspektive und

Figur 9:

eine weitere Darstellung der Anordnung aus Fig. 8 in Perspektive.

An embodiment of the present invention will be explained in more detail below with reference to drawings. Show it:

FIG. 1:

a schematic representation of a reflector according to the invention in perspective,

FIG. 2:

another illustration of the reflector of the Fig. 1 in perspective,

FIG. 3:

the reflector of Fig. 1 in cross-section along the section line A,

FIG. 4:

the reflector of Fig. 3 in cross-section along the section line B,

FIG. 5:

the reflector of Fig. 3 in cross section along the section line C,

FIG. 6:

the reflector of Fig. 3 in cross-section along the section line D,

FIG. 7:

the reflector of Fig. 3 in cross-section along the section line E,

FIG. 8:

an arrangement of four reflectors according to the invention in perspective and

FIG. 9:

another illustration of the arrangement Fig. 8 in perspective.

For the following statements applies that the same parts are denoted by the same reference numerals, if reference signs are included in a drawing, which is not discussed in detail in the accompanying figure description, reference is made to previous or subsequent description of the figures.

The Figures 1 and 2 show a reflector 1 according to the invention with a light entry end 2, a light exit end 3 and a reflector shell 7, which extends between the light entry end 2 and the light exit end 3. At the light exit end 3, a light exit opening 6 is formed. On the inside of the reflector shell 7, the reflector surface 4 is formed. The reflector has a flattened light entry end 2 with a base 8. The base 8 is quadrangular, wherein the edges are convex. At the base 8 a light inlet opening 5 is formed. The reflector surface 4 surrounds the optical axis O of the reflector 1. In the illustrated embodiment, the light inlet opening 5 and the light exit opening 6 are formed square, and coaxially aligned with the optical axis O and parallel to each other.

The reflector 1 was produced by injection molding, in which case a reflector body comprising the reflector shell 7 was first produced, and then the reflector surface 4 was applied to the inside of the reflector shell 7 as a reflective coating. In order to facilitate demolding during injection molding of the reflector 1, the outside of the reflector shell 7 is convex. The outer side follows the curvature of the reflector surface 4, so that the reflector shell 7 has a substantially constant wall thickness.

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

The spirals 9 each extend from a center of the edges of the base 8 to a respective corner of the light exit opening 6. The spirals 10 extend from one corner of the base 8 to a respective center of the edges of the light exit opening 6.

FIG. 3 shows the reflector of the FIG. 1 in section along the section line A. The reflector surface 4 is formed parabolic in the illustrated embodiment. Base 8 and light exit opening 6 are parallel to each other.

FIG. 4 shows the second transition region 13 of the reflector 1 of FIG. 3 in section along the axis B. The octagon 11 is almost completely in the shape of the base 8 has gone over, and has in relation to the base 8 a small angle of rotation α of about 5 ° about the axis of rotation R.

FIG. 5 shows the reflector of the FIG. 3 along the section line C. The polygon 11 defined by the reflector surface 4 is a point-symmetrical octagon 11 with a 4-fold rotational symmetry which rotates about its center of symmetry. The edges of the octagon 11 are convex.

FIG. 6 shows the reflector of the FIG. 3 along the section line D. The octagon 11 is still point-symmetrical and has a 4-fold rotational symmetry. However, the shape of the octagon 11 has changed them slightly, since the corners defining the spirals 9 to reach the corners of the light exit opening number 5 must travel a greater distance than the corners defining the spirals 10. The angle of rotation α is now approximately 30 °.

FIG. 7 shows the first transition region 12 of the reflector of FIG. 3 along the section line E. The octagon 11 continues to rotate and has almost completely transitioned into the shape of the light exit opening. The rotation angle α is almost 45 °.

The FIGS. 8 and 9 show an assembly 14 of 4 reflectors 1.15, the reflectors 15 to the reflector of Figures 1-7 correspond, but have an opposite sense of rotation. The 4 Lichteintrittsenten 3 are adjacent in a plane.

Claims (11)

1. Reflector (1) for a luminaire, in particular for a luminaire with at least one LED light source, comprising a light inlet end (2), a light outlet end (3) with at least one substantially rectangular light outlet opening (6), an optical axis (0), and a reflector surface (4) which extends between said light inlet end (2) and said light outlet end (3), where said reflector surface (4) at least in sections in a plane perpendicular to said optical axis (0) defines a polygon,
   where the reflector surface (4) is formed such that said polygon between said light inlet end (2) and said light outlet end (3) at least in sections rotates about an axis of rotation (R) which is oriented parallel to said optical axis (0),
   where said reflector (1) is flattened at said light inlet end (2) and said reflector surface (4) at said flattened light inlet end (2) opens to a base area (8),
   said light outlet opening (3) and said base area (8) are formed substantially square-shaped, and said polygon is a point-symmetrical octagon (11) with a 4-fold rotational symmetry,
   and where said reflector surface (4) is designed such that it extends parabolically in a plane parallel to said optical axis (0) between said light inlet end (2) and said light outlet end (3), and said polygon rotates between said base area (8) and said light outlet opening (3) along said entire reflector surface (4) such that the corners of said base area (8) transition to those corners of the octagon (11) which open to the centers of said edges of said light outlet opening (3), 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. Reflector (1) according to claim 1, characterized in that the edges of said polygon are formed in a curved manner.
3. Reflector (1) according to claims 1 or 2, characterized in that said polygon is point-symmetric and the center of symmetry is located on said axis of rotation (R).
4. Reflector (1) according to one of the preceding claims, characterized in that said rotational angle swept through by a corner of said polygon in a plane perpendicular to said axis of rotation (R) due to the rotation between said light inlet end (2) and said light outlet end (3) is greater than 15°.
5. Reflector (1) according to one of the preceding claims, characterized in that said rotational angle of each corner is substantially 360° divided by the number of corners of said polygon.
6. Reflector (1) according to one of the preceding claims, characterized in that said reflector surface (4) is formed in a parabolic manner in a plane parallel to said optical axis (0) between said light inlet end (2) and said light outlet end (3).
7. Reflector (1) according to one of the preceding claims, characterized in that said reflector comprises a light inlet opening (5) at said light inlet end (2).
8. Reflector according to one of the preceding claims, characterized in that said base area (8) is formed to be substantially rectangular, and a second transition region is formed at said light inlet end (2) in which said polygon transitions continuously to the shape of said base area (8).
9. Reflector (1) according to one of the preceding claims, characterized in that said reflector is produced by way of injection-molding.
10. Arrangement comprising at least two reflectors according to one of claims 1 to 9, characterized in that said light outlet openings (6) of said reflectors (1) are disposed adjacently and the rotations of said polygons of adjacent reflectors (1) have an opposite direction of rotation.
11. Luminaire with a reflector (1) and a light source, characterized in that said reflector is formed according to one of the claims 1 to 9, and said light source is disposed at said light inlet end (2) of said reflector (1) and comprises at least one LED.

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