EP2629001B1 - LED-Lamp with Optical element - Google Patents

Description

The invention relates to an LED lamp (LED: light-emitting diode) with a light influencing arrangement for optically influencing the light emitted by the LEDs.

Such an LED light in the form of an elongated beam light is from the font DE 10 2010 003 805 A1 known. The luminaire has an elongated optical element which includes lens areas for the individual LEDs. The LEDs are mounted on a profile body made of aluminum for effective heat dissipation via a printed circuit board. When the lamp heats up during operation, the optical element, which is typically made of plastic, expands more than the profile body made of aluminum. As a result, the position of the lenses relative to the LEDs generally changes slightly, resulting in the consequence that the optical effect of the lenses may change, so that the light output of the lamp as a whole is changed in an undesirable manner , This effect is correspondingly more pronounced the longer the lamp is.

From the US 8,070,329 B1 For example, an arrangement for emitting light is known which comprises an LED light source and different optically successive lens elements.

From the WO 2007/035835 A2 For example, a lighting device with a plurality of LEDs arranged on an elongate printed circuit board is known, the light of which is influenced by two circular cylindrical lens elements.

From the US 2007/0076427 A1 is a linear lighting device with LEDs and profile-like lens elements known.

The invention has for its object to provide an improved LED lamp; It should be possible with the lamp in particular, an undesirable to avoid or at least reduce the temperature fluctuation-related optical effect.

This object is achieved according to the invention with the object mentioned in the independent claim. Particular embodiments of the invention are indicated in the dependent claims.

According to the invention, there is provided an LED luminaire having at least one elongate board and LEDs disposed one behind the other on the at least one elongated board and adapted to emit a light. Furthermore, the LED lamp has a light influencing arrangement for optically influencing the light emitted by the LEDs. The In this case, the light influencing arrangement comprises a first subarea and a second subarea arranged behind the first subarea in a propagation direction of the light, the first subarea and the second subarea each consisting of a transparent material and each being lens-like.

In this way, the second subarea can be arranged relative to the first subarea so that a thermal expansion of the second subarea does not transfer to the first subarea. This makes it possible to achieve a particularly exact positioning of the first portion relative to the LEDs.

By a corresponding two-part design of the light influencing arrangement can be seen in the propagation direction of the light four refractive or -influential surface areas, instead of only two such surface areas, as typically in the case of a corresponding one-piece light influencing element. The possibilities for designing the optical effect of the light influencing arrangement are thereby improved. For example, both the first partial area and the second partial area can each be designed as a "complete lens" with surfaces curved on both sides.

Furthermore, with reference to the direction of propagation, an "internal" surface area, that is to say, for example, a surface area of the second partial area facing the first partial area, can be roughened in order to achieve a diffusion effect of the light. In this way, a corresponding diffusion effect can be achieved without having to roughen the surface area of the second subarea which is opposite or "outwards". The latter can thus be smooth, so that, for example - if the second portion forms an outer surface of the LED light - facilitated cleaning of the LED light is possible. In addition, in this way the internal or roughened surface area of the LED light can be better protected against dust or dirt, etc. A correspondingly inner surface can therefore also be made more flexible, for example by using particularly sensitive, finely structured surface elements, fracture-susceptible surface structures, dirt-prone lens surfaces, etc.

Another advantage is that the LED light can be converted more easily and cheaply if other LEDs with different mutual distances are to be used. Typically, as the light output of LEDs increases, the intended number of LEDs typically decreases, increasing their intended mutual spacing.

Furthermore, a more cost-effective production is basically possible, since smaller optically active elements can in principle be produced with smaller, less expensive tools.

Preferably, the second portion consists of one piece. In this way, transverse to the longitudinal direction of the at least one, elongated board extending bumps or transitions on the second portion can be avoided. This makes it particularly easy to seal the LED light; In addition, a particularly simple designed, even appearing end surface of the light influencing arrangement is possible.

The second subregion preferably forms a light exit element of the LED light. In this way, in particular, no separate end plate must be provided. In addition, in this case, the outer surface of the second portion, which points in the direction of propagation, can be made plane, which allows a particularly simple cleaning of the LED lamp.

According to the invention, the LED lamp further comprises a lamp housing, wherein the second portion is arranged on the lamp housing. In this way, separate holding elements for the second portion can be avoided so that components and material can be saved. Furthermore, according to the invention, the second subarea is arranged with play on the luminaire housing in such a way that the second subarea can shift relative to the luminaire housing in the event of material fluctuations due to temperature fluctuations.

Preferably, the second portion is designed profile-shaped and arranged parallel to the at least one elongated board. This way you can avoid that a small, relative to the temperature variation caused by relative movement of the second portion vis-à-vis the first portion or the LEDs has an optical effect. The first subarea preferably comprises light-guiding elements which are arranged along a longitudinal axis defined by the at least one elongate board. The light-guiding elements are preferably designed or shaped in each case like a truncated pyramid or truncated cone. In this case, each of the light-guiding elements is preferably associated with one of the LEDs. As a result, a particularly targeted influencing of the light of the LEDs can be effected.

Preferably, at least two of the light-guiding elements are separated from one another or designed to be incoherent. In this way, it is possible to achieve that the positions of the individual light-guiding elements relative to the LEDs are particularly well preserved or unaffected given corresponding thermally induced material expansions. For example, the light-guiding elements are all designed to be separated from each other. However, it can also be provided that groups of some light-guiding elements are designed to be continuous, the length of these groups along the longitudinal axis being selected such that the relative positioning of the groups with respect to the LEDs is maintained to the desired extent in the event of temperature fluctuations. Such a configuration of groups of light-directing elements can be advantageous in comparison with a configuration in which all the light-directing elements are formed separately with respect to the assembly and tooling required to produce the LED light.

Preferably, the light-guiding elements are arranged stationary relative to the at least one elongated board. This makes it easy to ensure a desired alignment of the light-guiding elements with respect to the LEDs. For example, this positioning means may be provided. Suitably, the light-guiding elements can be fixed to the at least one printed circuit board by means of an adhesive and / or latching connection.

According to the invention, the first subarea has a planar surface area and the second subarea has a plane surface area, wherein the first subarea is arranged in such a way that it faces the planar surface area of the second subarea with its planar surface area. In this way, a particularly good coupling of the light from the first partial area into the second partial area is made possible.

The second subarea and / or the first subarea preferably has a guide element, by means of which the first subarea is secured in its position relative to the second subarea in a direction perpendicular to the at least one elongate board.

A particularly good design possibility of the optical effect of the light influencing arrangement is made possible if the second subregion is arranged to be adjustable in at least one direction perpendicular to the at least one elongate board and / or about an axis of rotation oriented in particular parallel to the at least one elongate board.

If the first subregion consists of a different material than the second subregion, a particularly expedient material can be selected for each of the two subregions; For example, a particularly resistant material can be selected for the second subregion; This is advantageous, for example, if an outer surface of the LED light is formed by the second portion.

Fig. 1

eine perspektivische Skizze zu einem Ausführungsbeispiel,

Fig. 2

eine Querschnittskizze zu dem Ausführungsbeispiel,

Fig. 3

eine perspektivische Skizze zu einer Variante des Ausführungsbeispiels und

Fig. 4

eine Skizze zu einer weiteren Variante.

The invention is explained in more detail below with reference to exemplary embodiments and with reference to the drawings. Show it:

Fig. 1

a perspective sketch of an embodiment,

Fig. 2

a cross-sectional diagram of the embodiment,

Fig. 3

a perspective sketch of a variant of the embodiment and

Fig. 4

a sketch to another variant.

Fig. 1 shows a sketch of a first embodiment of an LED lamp according to the invention, also referred to here for short as a lamp. The luminaire has at least one elongate circuit board 2, on which LEDs 3 are arranged one behind the other. By the elongated shape of the at least one elongated board 2 may be a longitudinal axis L set. Several, in particular similar, elongated blanks 2, each oriented parallel to the longitudinal axis L , can be arranged one behind the other along the longitudinal axis L. Preferably, the light itself is elongated so that it extends along the longitudinal axis L. It can be a fluorescent tube.

The LEDs 3 are preferably arranged on a straight line parallel to the longitudinal axis L or along the longitudinal axis L around the straight line.

The LEDs 3 are configured to emit a light. In particular, the LEDs 3 may form a light source of the lamp, wherein the lamp is adapted to emit the light of the LEDs 3 in an outdoor area of the lamp.

Furthermore, the luminaire has a light influencing arrangement 4 for optically influencing the light emitted by the LEDs 3.

The light influencing arrangement 4 comprises a first subregion 5 and a second subregion 6 arranged behind the first subregion 5 in a propagation direction R of the light. The light influencing arrangement 4 can consist of the first subregion 5 and the second subregion 6. As from the sketch of Fig. 1 As can be seen, the light can be designed such that the propagation direction R is oriented normal to a plane defined by the at least one board 2, in particular at right angles to the longitudinal axis L.

The first subregion 5 of the light influencing arrangement 4 and the second subregion 6 of the light influencing arrangement 4 each consist of a transparent material, in particular of plastic. In this case, the first subregion 5 can consist of a different material than the second subregion 6.

In addition, both subregions 5, 6 are each designed lens-like. The two subregions 5, 6 thus have a correspondingly curved or arched surface at least at one point.

The first subregion 5 and the second subregion 6 are in particular designed to be separate from each other or disconnected. Thus, it is possible with a particularly simple design that a temperature change-related expansion of the second portion 6, in particular in the direction of the longitudinal axis L, is not transferred to the first portion 5. The preservation of the relative positioning of the first portion 5 relative to the LEDs 3 can thereby be ensured even when temperature changes to the desired extent.

The first sub-area 5 may comprise individual light-guiding elements 8 which are arranged along the elongate board 2 or along the longitudinal axis L. The light-guiding elements 8 can - as exemplified in Fig. 1 sketched - truncated pyramid or frustoconical designed. The light-guiding elements 8 can be designed identical. In Fig. 2 is a corresponding cross section normal to the longitudinal axis L sketched.

As can be seen by way of example from the sketches, the light-guiding elements 8 can be similarly shaped and, because of their shape, have a base 81, a top surface 82 and lateral surfaces 83 which connect the base 81 to the top surface 82.

Preferably, each light-guiding element 8 is assigned to exactly one of the LEDs 3. The light-guiding elements 8 preferably each have a main axis oriented parallel to the propagation direction R, which is oriented in particular at right angles to the longitudinal axis L , wherein the desired relative positioning of the light-directing element 8 to the respective associated LED 3 is such that the main axis passes through the relevant axis LED 3, or whose center runs.

The light-directing elements 8 can each have a recess 84 in their cover surfaces 82, which is configured in such a way that one of the LEDs 3 or the respective associated LED 3 can be positioned engaging in the recess 84. This is particularly effective in terms of photometry.

Preferably, the design is furthermore such that the light-guiding elements 8, in particular with their cover surfaces 82 or in each case on their, the relevant LED 3rd side facing each directly contact the at least one board 2. How out Fig. 2 As can be seen, this contacting can be provided on at least two opposite sides, in particular with reference to the corresponding LED 3 placed in the recess 84. In this way, a desired relative positioning of the light-directing element 8 with respect to the board 2 and thus with respect to the LED 3 can be ensured particularly well.

As is known per se, the configuration of the light-guiding elements 8 may be such that the light is totally reflected at least partially on the lateral surfaces 83, so that a light deflection around the propagation direction R is effected and the light subsequently emerges through the base 81 of the light-directing element 8 ,

The light-guiding elements 8 can be connected to one another in such a way that relative movements between the light-guiding elements 8 or at least groups of light-guiding elements 8 in the direction of the longitudinal axis L are possible. For example, the light-guiding elements 8 may be connected to one another by correspondingly movably configured webs. By means of a corresponding relative mobility, it can be achieved that the desired relative positioning of the light-guiding elements 8 with respect to the LEDs 3 is maintained to the desired extent with a temperature-induced expansion or no "falsification" of the light distribution occurs.

Alternatively, it can be provided for this purpose that the light-guiding elements 8 are preferably separated from one another at at least one point or designed to be incoherent. For example, all light-guiding elements 8 can each be designed as separate parts. However, it is also possible for groups of light-guiding elements 8 to be formed, these groups being only so long in the direction of the longitudinal axis L that the desired relative positioning of the light-guiding elements 8 with respect to the LEDs 3 can be ensured to a sufficient extent in the event of temperature fluctuations. Formation of corresponding groups may be preferred in terms of manufacturing because of assembly and manufacturing advantages.

Thus, the effect can be achieved that the light-deflecting elements 8 with respect to the at least one board 2 and the LEDs 3 arranged thereon in quasi at a temperature change caused by expansion of the first portion 5 remain unchanged relative positions. This makes it possible to ensure that the optical effect on the light of the LEDs 3 caused by the light-guiding elements 8 remains virtually unchanged even when the temperature changes.

Accordingly, the light-directing elements 8 are arranged relative to the at least one board 2 expedient location or fixed. For this purpose, for example, positioning means may be provided. For example, positioning pins can be provided on the light-guiding elements 8, which for this purpose engage in corresponding corresponding recesses which are formed on the at least one printed circuit board 2. As a result, an axial securing of the light-guiding elements 8 can be ensured particularly well.

The light-guiding elements 8 can also be fixed to the at least one printed circuit board 2 by means of at least one adhesive and / or latching connection.

The second portion 6 preferably consists of one piece or of only one piece. The second portion 6 is therefore preferably formed in a coherent manner. In this way, it can be avoided that joints are formed by the second portion 6, which extend transversely to the longitudinal axis L. This makes it possible to improve the visual appearance of the lamp. In addition, the light can be cleaned more easily in this case. Since joints always represent special attachment sites for pollution, it is easier to avoid contamination of the luminaire itself in this way.

Advantageously, the second portion 6 forms a light exit element of the lamp. This eliminates the need for a separate end plate. In this case, it may be expedient if the first portion 5 made of a different material than the second portion 6; In particular, the second subregion 6 may consist of a more resistant material than that of the first subregion 5. Thus, the outer surface formed by the second subregion 6 may be particularly resistant.

How out Fig. 2 shows, it is preferably provided that the lamp has a lamp housing 7, wherein the second portion 6 on the lamp housing 7 is arranged. The luminaire housing 7 can be formed, for example, by a profile body extending in particular along the longitudinal axis L , which consists for example of aluminum. For arranging the second subarea 6, the luminaire housing 7 can have bearing surfaces 71 on which the second subarea 6 rests with bearing surfaces 61 of the second subarea 6. Preferably, the second portion 6 is arranged on the luminaire housing 7 with play such that the second portion 6 can move relative to the luminaire housing 7 in material fluctuation caused by temperature fluctuation. In this way, it is possible to avoid that corresponding voltages of the second subarea 6 build up, which could be detrimental to the desired optical effect.

For example, for this purpose, the bearing surfaces 71 of the lamp housing 7 may be designed to be elongated, so that they extend along the longitudinal axis L , wherein at the two, given with respect to the longitudinal axis L end portions of the lamp housing 7 is provided in accordance with sufficient clearance for the second portion 6.

A particularly simple embodiment is made possible when the second portion 6 is designed in the shape of a profile and is arranged such that it extends parallel to the longitudinal axis L. In the case of a temperature fluctuation-caused expansion in the direction of the longitudinal axis L , a disadvantageous effect on the optical effect of the light-influencing element 4 or of the second subregion 6 can be avoided in this way.

The second portion 6 may be designed, for example, as a lenticular lens.

As in Fig. 1 sketched, the first portion 5 may have a planar surface area 55 and the second portion 6 a flat surface area 65, wherein the first portion 5 is arranged such that it has with its planar surface area 55 on the planar surface portion 65 of the second portion 6. In this way, the light that comes from the first portion 5, particularly good in the second portion 6 einkoppeln.

It may be provided that the first portion 5 or the light-guiding elements 8 rests or rest on the planar surface area 65; in In this case, therefore, only one air gap exists between the two subregions 5, 6.

In particular, it can thus be provided in this case that the second subregion 6 is arranged such that its planar surface region 65 is oriented horizontally when the luminaire is aligned as intended for operation.

In this embodiment it can be provided that the light-guiding elements 8 can slide on the plane surface region 65 of the second subregion 6 in the direction of the longitudinal axis L.

In Fig. 3 a sketch is shown to a variant in which additionally the second portion 6 has a guide element 9, by which the first portion 5 is secured relative to the second portion 6 in a direction r1 perpendicular to the at least one elongated board 2 in its position. In particular, the guide element 9 may be formed by a web which extends in the direction of the longitudinal axis L. Preferably, two such guide elements 9, 9 'are provided, by which the first portion 5 is secured in two opposite directions r1, r2 in its position. As a result, the first subregion 5 can thus be fixed "laterally" in relation to the second subregion 6.

How out Fig. 3 hinted, the guide member 9 and the guide elements 9, 9 'may be designed such that thereby the relative arrangement of the two sections 5, 6 along the propagation direction R is secured; with reference to the representation of Fig. 3 So is a lifting of the light guide elements 8 to "above" by the guide elements 9, 9 'prevented. Of course, a displacement of the first portion 5 relative to the second portion 6 in the direction of the longitudinal axis L in the sense of the above statements given or made possible.

In Fig. 4 a sketch is shown to a further variant in which the second portion 6 in at least one direction r1, r2 , r3, r4 perpendicular to the at least one elongated board 2 and the longitudinal axis L and / or one, in particular parallel to the at least an elongated board 2 and the longitudinal axis L oriented Rotary axis is arranged adjustable. The latter is in Fig. 4 indicated by the curved double arrow d. For example, it can thus be provided that the distance between the first subregion 5 and the second subregion 6 can be adjusted in the direction of propagation.

In this case, it is not necessarily the case that the two partial regions 5, 6 abut one another. In this variant, it can be provided that the two subregions 5, 6 have a fixed relative position after mounting the luminaire; but it can also be provided that the position of the second portion 6 relative to the first portion 5 can be adjusted by a user during operation of the lamp.

As described above, both subregions 5, 6 are each designed lens-like, so that they have a curved or arched surface at least at one point. When using the Fig. 1 As shown, the second portion 6 has a convex curvature 62 on its surface facing in the propagation direction R. This curvature 62 may preferably be configured in the form of a profile so that it extends at least over a longitudinal region along the longitudinal axis L , which comprises a plurality of the LEDs 3, preferably over the entire length of the second subregion 6 Fig. 3 the variant shown, the second portion 6 has a corresponding protrusion 62. At the in Fig. 4 In the variant shown, a corresponding curvature 63 on the opposite side may be formed on the second subarea 6, alternatively or additionally to the curvature 62 mentioned above, ie on the side facing the propagation direction R.

The first subregion 5 may, in particular, have a curvature facing the LED 3, which is formed by said recess 84. This curvature or the recess 84 may preferably have an invariable in the direction of the longitudinal axis L cross-section, as seen from Fig. 3 suggestively.

At the in Fig. 4 the variant shown, the first portion 5 also on the opposite side, ie in the propagation direction R have a corresponding protrusion 52. In general, therefore, by the first portion 5 and the second portion 6 viewed in a cross section normal to the longitudinal axis L seen two curved on both sides lenses to be formed.

Claims (12)

1. LED lamp, having

   - at least one elongated circuit board (2),

   - LEDs (3), arranged behind one another on the at least one elongated circuit board (2) and configured to emit a light, and

   - a light-influencing arrangement (4) for optically influencing the light emitted by the LEDs (3),

   wherein the light-influencing arrangement (4) comprises a first partial area (5) and a second partial area (6) arranged in a direction of propagation (R) of the light behind the first partial area (5), wherein the first partial area (5) and the second partial area (6) are respectively made of a transparent material and respectively have a lens-like design, and

   - a lamp housing,

   characterized in that the first partial area (5) has a plane surface section (55) and the second partial area (6) has a plane surface section (65) and the first partial area (5) is arranged in such a way that it points with its plane surface section (55) to the plane surface section (65) of the second partial area (6), wherein the second partial area (6) is arranged on the lamp housing (7) with slack in such a way that the second partial area (6) can move itself with temperature fluctuation-related material expansions relatively to the lamp housing (7).
2. LED lamp according to claim 1, where the second partial area (6) is made of one piece.
3. LED lamp according to claim 1 or 2, where the second partial area (6) forms a light exit element of the LED lamp.
4. LED lamp according to one of the preceding claims, where the second partial area (6) is profile-shaped and at the same time arranged parallel to the at least one elongated circuit board (2).
5. LED lamp according to one of the preceding claims, where the first partial area (5) comprises light-directing elements (8) that are arranged alongside a longitudinal axis (L), defined by the at least one elongated circuit board (2), wherein the light-directing elements (8) have preferably a respectively truncated pyramid-like or truncated cone-like design.
6. LED lamp according to claim 5, where each of the light-directing elements (8) is assigned to one of the LEDs (3) respectively.
7. LED lamp according to claim 5 or 6, where at least two of the light-directing elements (8), for instance all of the light-directing elements (8) are separate from one another.
8. LED lamp according to one of the claims 5 to 7, where the light-directing elements (8) are arranged in a stationary manner relative to the at least one circuit board (2), preferably by positioning means.
9. LED lamp according to claim 8, where the light-directing elements (8) are fastened on the at least one circuit board (2) by means of an adhesive connection and/or snap-on connection.
10. LED lamp according to one of the preceding claims, where the second partial area (6) and/or the first partial area (5) has a guide element (9) by which the first partial area (5) is secured in its position relative to the second partial area (6) in a direction (r1) vertical to the at least one elongated circuit board (2).
11. LED lamp according to one of the preceding claims, where the second partial area (6) is arranged in an adjustable manner in at least one direction (r1, r2, r3, r4) vertical to the at least one elongated circuit board (2) and/or around an axis of rotation oriented in particular parallel to the at least one elongated circuit board (2).
12. LED lamp according to one of the preceding claims, where the first partial area (5) is made of a different material than the second partial area (6).

Images