EP2697559B1 - Luminaire - Google Patents

Description

By introducing light-emitting diodes as light sources, it is possible to replace a number of conventional light sources with such LEDs. However, LEDs are characterized by specific features that make it difficult to continue to use such light sources.

For example, LEDs are point-shaped light sources, which are also perceived in this way by a viewer. Even if a plurality of such light sources is used, a corresponding plurality of punctiform light sources results, in particular under direct illumination, and corresponding shadows can occur due to the use of this plurality of LEDs, which altogether complicate the illumination by means of these light sources.

Furthermore, an LED is a very intense light source, which easily leads to a glare effect and possibly even leads to a harmful influence on the eye of an observer.

These disadvantages are more pronounced when a plurality or plurality of such LEDs are provided in a linear arrangement.

In such light sources is further noted that the heat generated can not be neglected and possibly separate measures for cooling and the like must be taken.

DE 20 2011 003 261 U1 discloses a luminaire insert for a luminaire housing. In particular, a floor lamp is disclosed which projects light obliquely onto a wall surface. In the luminaire insert different groups of LEDs are arranged. Each group of light-emitting diodes is assigned a one-part or multi-part reflector. This has one or more reflector areas. The arrangement and / or alignment of the groups takes place in such a way that the luminous flux emitted by the one group of light-emitting diodes is reflected by the associated reflector into a predetermined area of the wall surface and that the luminous flux emitted by the other group of light-emitting diodes is assigned by the in turn assigned one Reflector is reflected in another predeterminable area of the wall surface.

Likewise describe the WO2010 / 070565 . US2010 / 0327768 and US2010 / 0182782 Luminaires according to the prior art.

The invention has for its object to provide a luminaire with LEDs, in which a plurality of such bulbs in a simple manner and without the disadvantages mentioned above can be used or greatly reduced, for example, to replace fluorescent tubes or the like as usual bulbs.

According to the invention, a corresponding plurality of LEDs in the longitudinal direction of the luminaire are arranged behind one another in an LED spacing by means of an LED carrier. Each LED emits light in a certain solid angle range around a Abstrahlmittelrichtung. Each solid angle range of an LED is directed towards a luminaire reflector for indirect light emission of the luminaire. LED number and / or LED distance are selected so that the solid angle ranges of all LEDs after reflection on the luminaire reflector at least partially in a lighting surface distance from a bottom of the lamp of at least 0.2 to 2.5 times the distance of the spaced apart LEDs overlap.

According to the invention, the LEDs are thus arranged one behind the other along the lengthwise direction of the lamp and the emitted light is emitted by the luminaire only after a corresponding reflection on the luminaire reflector. At the same time, the reflection takes place in such a way that the corresponding solid angle ranges of all LEDs overlap at least partially, whereby a corresponding overlap also takes place correspondingly in the case of the most widely spaced LEDs. In order to ensure, at a suitable distance from the luminaire, that such an overlap takes place for corresponding observers, the at least partial overlap occurs already at a distance of at least 0.2 to 2.5 times the distance of the most widely spaced LEDs. This means that with a maximum distance of the LEDs within the luminaire of, for example, one meter the furthest spaced LEDs overlap with their solid angle ranges already in 20 cm or at least at a distance of 2, 5 meters from the lamp base.

In this way it is prevented that the LEDs are still perceived as punctiform single light sources. Furthermore, the intensity of the LEDs is correspondingly weakened by the corresponding reflection and distribution of their light output, or at least distributed over a larger area, so that no damaging effects can occur for the eyes of an observer. The corresponding light distribution and indirect emission of light via the luminaire reflector.

Overall, this results in a relatively homogeneous light source despite the majority of individual LEDs used. At the same time, appropriate shadowing is prevented and glare caused by the LEDs is avoided.

A solid angle range in which an LED lights, is usually 90 ° to 140 ° depending on the LED type.

At the same time, according to the invention, due to the avoidance of glare, the LEDs can be arranged in part closer relative to one another or else in smaller groups.

For the corresponding distribution of the light emission of each LED and the overlap of the different solid angle ranges, it is sufficient if the luminaire reflector in the longitudinal direction of the lamp is rectilinear. D. h., Until possibly on end portions of the luminaire reflector, this extends in the lamp longitudinal direction straight without curvatures.

In order to be able to influence the light distribution in the transverse direction to the luminaire in a certain way, the luminaire reflector in the luminaire transverse direction is composed of a number of substantially planar or curved reflector surfaces. Depending on the arrangement of these reflector surfaces results in a corresponding light distribution in the transverse direction of the lamp, which can also be modeled on a fluorescent tube or the like in terms of their emission.

All reflector surfaces are interconnected, so that essentially a one-piece luminaire reflector is used.

The various reflector surfaces are inclined relative to each other for fixing an illumination angle common to all LEDs. By way of example, a corresponding illumination angle of at least LEDs arranged along a row can be 30 °, 40 ° or even 45 °. Other illumination angles are also possible.

The arrangement of corresponding LED carrier is such that they are arranged outside the reflected solid angle range of each LED.

In the luminaire according to the invention, it is also conceivable that two or more groups of LEDs are arranged side by side in the transverse direction of the lamp. This corresponds, for example, to the arrangement of two or more fluorescent tubes. With regard to these groups of LEDs, it is also possible for each group to determine a specific illumination angle by arranging the reflector surfaces. The illumination angles of each group of LEDs may be different.

Furthermore, it is conceivable that the illumination angles of the LED groups overlap each other and determine a total of a certain illumination angle.

For the arrangement of the LED groups, it may be advantageous if each LED group is associated with an LED carrier. This makes the LED groups separately manageable and interchangeable.

Depending on the arrangement of the LED groups, it is also conceivable that only one LED carrier is provided for both LED groups.

The corresponding LED carrier is usually also used as a cooling device for the LEDs. In this context, it may be advantageous if the light carrier has cooling fins The LED support can also be designed without cooling surfaces and, for example, directly attached to the luminaire housing or be part of this.

In particular, in the arrangement of two LED groups, the structure of the luminaire reflector can be simplified if the reflection surfaces for each LED group are arranged in mirror image to each other. Also conceivable is an asymmetric arrangement to concentrate light, for example, by appropriate reflection in certain areas.

This can be achieved in that all reflection surfaces for all LED groups are formed by only one luminaire reflector.

For easy handling and attachment of the lamp, it may have a luminaire housing with at least in the light emission direction transparent or translucent housing part. It is also conceivable that the luminaire housing is open in the light emission direction.

Within the luminaire housing, for example, the luminaire reflector can be releasably held. The corresponding holding can be done by screwing or the like. It is also conceivable that the luminaire reflector is latched to lateral end portions in the luminaire housing, so that no further measures for attachment must be taken. The luminaire reflector can also form a fixed unit with the luminaire housing.

It is also possible that the LEDs of each LED group form two substantially separate illumination areas. Some overlap may occur between these areas of illumination, but essentially each group of LEDs will illuminate in parallel directions and spaced solid angle ranges. Only at a certain distance from the luminaire can an overlap of the solid angle or illumination areas take place, which increases with increasing distance to the luminaire, ie the illumination areas are increasingly mixed.

In order to use the light in hazardous areas, the LEDs can be designed in the appropriate type of protection such as Ex-d or Ex-m.

This can be done by the LEDs are shed with associated cooling surface or heat sink. The LEDs can be formed by an LED strip with a corresponding number of LEDs. This strip is placed on the cooling surface and covered with a cover for all LEDs of the corresponding strip. This cover can then be cast along its entire circumference by a corresponding potting compound relative to the holder of the LEDs, that the appropriate type of protection is realized.

In the following advantageous embodiments of the invention are explained in more detail with reference to the figures illustrated in the accompanying drawings.

• Figur 1 einen Querschnitt durch ein erstes Ausführungsbeispiel einer erfindungsgemäßen Leuchte;
• Figur 2 einen Querschnitt durch ein zweites Ausführungsbeispiel einer erfindungsgemäßen Leuchte, und
• Figur 3 einen teilweisen Längsschnitt durch die Leuchten der Figur 2 im Bereich einer LED-Gruppe.

Show it:

• FIG. 1 a cross section through a first embodiment of a lamp according to the invention;
• FIG. 2 a cross section through a second embodiment of a lamp according to the invention, and
• FIG. 3 a partial longitudinal section through the lights of FIG. 2 in the range of an LED group.

FIG. 1 shows a cross section, see lamp transverse direction 11, by a first embodiment of a lamp according to the invention 1. This has two groups of LEDs 2, see LED group 16 and 17. Both LED groups 16 and 17 are arranged on an LED support 5. This forms at the same time a heat sink with corresponding cooling fins 19. The LED groups 16, 17 are arranged in a specific LED spacing 4 on the associated carrier, see also FIG. 3 , All LEDs 2 are arranged on an LED strip which rests on a corresponding cooling surface of the LED carrier 5. The LEDs 2 are covered by a cover housing 27, which is encapsulated with the carrier 5, for example, so that the LEDs are formed in a corresponding type of protection such as Ex-d or Ex-m.

In the illustrated embodiment, the LEDs 2 of the respective groups 16 and 17 are inclined outwardly. Each LED emits light in a certain solid angle range 6, which in Fig. 1 is characterized by the various outgoing of the LEDs 2 rays. The entire solid angle region 6 impinges on different planar reflector surfaces 12, 13, 14, which together form a luminaire reflector 8. As a result, light in the solid angle region 6 is emitted indirectly by the luminaire, see also the corresponding solid angle ranges below the luminaire 1, which have corresponding illumination angles 15. The associated light emission direction 26 is directed away from the lamp 1 to a viewer. Each of the solid angle regions 6 has an emission means 7 around which the solid angle region 6 extends, see also the following figures.

The luminaire reflector 8 is integrally formed from a series of corresponding reflector surfaces 12, 13 and 14. The reflector surfaces are arranged symmetrically to a central axis of the lamp 1, so that the same parts of the luminaire reflector each LED group 16 and 17 are assigned.

On the basis of the arrangement of the corresponding reflector surfaces, there are essentially two solid angle regions 6, which are each assigned to a group 16, 17, see also the illumination regions 22 and 23 and the associated illumination angles 15, which are each arranged around a corresponding emission center direction 7.

The two solid angle regions 6 overlap at least in adjacent regions of the illumination regions 22 and 23.

The luminaire reflector 8 is arranged within a corresponding luminaire housing 20. At its end portions 24 and 25 of the light reflector 8 is locked within the lamp housing 20.

FIG. 2 shows a section analogous to FIG. 1 by a second embodiment of a erfindungemäßen lamp 1. In this light, the LEDs 2 are arranged separately from one another as LED groups 16 and 17 at lateral ends within the corresponding lamp housing 20. Each LED group 16 or 17 has a carrier 5 and 18, the analog to the carrier according to FIG. 1 can be constructed. Each of these carriers comprises at least one heat sink and a cover housing 27 for the LEDs 2 arranged in a row one behind the other in the longitudinal direction of the lamp.

The shape of the lamp housing 20 after Fig. 2 corresponds to that after Fig. 1 , However, the luminaire reflector 8 has a slightly different shape. Although it is made up of corresponding reflector surfaces 12, 13, 14 and the like, these reflect light emitted by the LEDs 2 in such a way that the corresponding solid angle regions 6 overlap one another in the illumination regions 22 and 23. In this case, the illumination angle 15 is substantially the same as the illumination angle 15 of FIG Fig. 1 coincide and is for example about 30 °.

Also in the embodiment according to Fig. 2 end portions 24 and 25 of the luminaire reflector 8 are releasably secured within the lamp housing 20 by latching. In this case, the same locking elements are used in the interior of the lamp housing 20, see in particular inwardly projecting latching hooks 29. Also in the embodiment according to Fig. 2 the corresponding LEDs 2 are designed in protection type Ex-d or Ex-m.

Incidentally, the same parts are denoted by the same reference numerals in all figures and are partially described in detail only in connection with a figure.

FIG. 3 shows a partial view of a longitudinal section through a lamp 1 after Fig. 2 , wherein the longitudinal section runs exactly along the linearly successively arranged LEDs 2 of an LED carrier 5 and 18 respectively. The light 1 is in Fig. 3 shown in half, see corresponding central axis 28, wherein the parts of the lamp discussed here are arranged in the same way in both halves of the lamp.

The various LEDs 2 are arranged in the lamp longitudinal direction 3 with a corresponding LED spacing 4 on the associated LED carrier 5. In particular, in Fig. 3 shown how the different solid angle regions 6 of the successively arranged LEDs 2 overlap each other after reflection on the luminaire reflector 8, see the different reflection at respectively angles of 20 ° to Abstrahlmittelrichtung 7 or the other reflections at 60 ° or 40 ° relative to this Abstrahlmittelrichtung. 7 The corresponding angle of 120 ° of the solid angle range 6 corresponds to the maximum emission angle of the LEDs 2 used here. The LED distance 4 and the corresponding number of LEDs 2 in the longitudinal direction of the luminaire 3 are chosen such that the LEDs 2 which are the most widely spaced apart in their reflected solid angle ranges 6 in a corresponding Illumination surface spacing 9 at least partially overlap, said illumination surface distance 9 corresponds to at least 0.2 to 2.5 times the corresponding distance of the spaced apart LEDs 2. The illumination area distance 9 is measured by an underside 10 of the luminaire 1, which essentially corresponds to the underside of a transparent or translucent housing part 21. The distance of the furthest spaced LEDs 2 after Fig. 3 equals the distance from the in Fig. 3 the leftmost LED 2 to the rightmost in the half not shown LED 2.

In Fig. 3 Some solid angle ranges 6 of adjacent LEDs 2 for an opening angle of 20 ° of the corresponding areas around the Abstrahlmittelrichtung 7 are shown. These too already overlap, which applies analogously to larger angles of the corresponding solid angle ranges with regard to more widely spaced LEDs 2.

Due to the corresponding overlap of the different solid angle regions 6 and the reflection of the light emitted by the LEDs 2 light at the corresponding luminaire reflector 8 results in a homogeneous distribution of light emission, so that punctiform light sources are no longer recognizable in the corresponding illumination surface distance 9. A glare effect through the different LEDs 2 also no longer occurs due to this homogeneous light distribution. Instead, the illumination image of the LEDs essentially corresponds to that of a fluorescent tube or of two fluorescent tubes arranged next to one another, see, for example Fig. 1 ,

By using a corresponding carrier with a corresponding cooling effect for the LEDs further cooling is not required and the LEDs can be arranged at a relatively small distance from each other. This results in the use of a corresponding cover housing 27 for the LEDs 2, a small free volume, which is for the corresponding explosion protection or training of the LEDs with appropriate ignition protection advantage.

Claims (14)

1. Lamp (1) with a plurality of LEDs (2) which are arranged one behind the other in the lamp's longitudinal direction (3) and each in LED spacing (4) by means of an LED carrier (5), whereby each LED (2) emits light in a certain solid angle area (6) around a beam centre direction (7), which solid angle area (6) is directed toward a lamp reflector (8) for indirect light emission of the lamp (1),
   characterised in that
   the number of LEDs and the LED spacing (4) is selected in such a way that the solid angle areas (6) of all LEDs overlap at least partially after the reflection at the lamp reflector (8) at an illumination surface distance (9) from an underside (10) of the lamp (1) of at least 0.2 to 2.5 times the distance between the LEDs that are spaced the farthest from each other, wherein the lamp reflector (8) runs in a straight line in the lamp's longitudinal direction (3) and is put together in the direction transverse to the lamp (11) from a number of essentially flat or curved reflector surfaces (12, 13, 14) connected to one another, wherein the reflector surfaces (12, 13, 14) are tilted relative to one another for establishing an illumination angle (15) common to all LEDs, and wherein the LED carrier (5, 18) is arranged outside the reflected solid angle area (6) of each LED.
2. Lamp according to claim 1 characterised in that two groups (16, 17) of LEDs are arranged next to one another in the lamp's longitudinal direction (3).
3. Lamp according to claim 1 or 2 characterised in that each LED group (16, 17) has an LED carrier (5, 18).
4. Lamp according to claim 1 characterised in that one LED carrier (5) is provided for both LED groups (16, 17).
5. Lamp according to claim 2 characterised in that the illumination angles (15) of the two LED groups (16, 17) overlap each other.
6. Lamp according to claim 2 characterised in that the reflection surfaces (12, 13, 14) for each LED group (16, 17) are arranged as the mirror image of the other or asymmetrically with respect to one another.
7. Lamp according to one of the preceding claims characterised in that all reflector surfaces (12, 13, 14) are formed by means of a lamp reflector (8).
8. Lamp according to one of the preceding claims characterised in that the LED carrier (5, 18) has cooling fins (19).
9. Lamp according to one of the preceding claims characterised in that the lamp (1) has a lamp housing (20) that is transparent or translucent at least in the light emission direction (26).
10. Lamp according to one of the preceding claims characterised in that the lamp reflector (8) is held in the lamp housing (20) in a detachable manner or forms a firmly attached unit with the same.
11. Lamp according to claim 2 characterised in that the LEDs of each group (16, 17) form two illumination areas (22, 23) that are essentially separated from each other and that intermix more and more particularly as the distance from the lamp increases.
12. Lamp according to one of the preceding claims characterised in that the lamp reflector (8) is latched in the lamp housing (20) at lateral end sections (24, 25).
13. Lamp according to one of the preceding claims characterised in that the LEDs are formed with ignition protection type Ex-d or Ex-m.
14. Lamp according to one of the preceding claims characterised in that the LEDs are encapsulated relative to the LED carrier by means of a shared LED cover housing and a casting compound.

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