WO2008125191A1

WO2008125191A1 - Illuminant

Info

Publication number: WO2008125191A1
Application number: PCT/EP2008/002402
Authority: WO
Inventors: Georg Diamantidis
Original assignee: Noctron Soparfi S.A.
Priority date: 2007-04-13
Filing date: 2008-03-27
Publication date: 2008-10-23
Also published as: CN101680605A; DE102007017900A1

Abstract

An illuminant (10) having a piston (14) is disclosed. The piston (14) has a piston axis (20) and a piston wall (16) made of translucent material at least partially delimiting an interior space (22) of the piston (14). A first contact element (24) and a second contact element (26) can have voltage applied to them and are located in the interior space (22) of the piston (14). At least one semiconductor light chip (28, 28'), which emits light when voltage is applied, is connected to the first and the second contact elements (24, 26). The piston wall (16) is externally thermally conductively connected to a convection cooling structure (36, 44).

Description

Lamp

The invention relates to a lighting means according to the preamble of claim 1.

During operation of such light sources, the semiconductor light-emitting chip heats up, which is why heat must be dissipated therefrom in order to reduce the danger of overheating with the possible consequence of complete destruction of the light source.

The object of the invention is therefore to provide a lighting means of the type mentioned, in which a reliable heat dissipation from the semiconductor light-emitting chip or from the piston is ensured.

This is achieved in a luminous means of the type mentioned above in that the bulb wall is externally connected thermally conductively connected to a convection cooling structure.

A convection cooling structure absorbs the heat generated by the semiconductor light-emitting chip and leads it outward. Initially, the convection cooling structure itself is heated. This heat is transferred to the environment, mostly air, the convection cooling structure. The air so heated then flows upwardly away from the convection cooling structure, with cooler ambient air flowing in, resulting in uniform heat transfer from the convection cooling structure to the environment.

Advantageous developments are specified in the dependent claims. The formation of the convection cooling structure according to claim 2 and 3 enables a large surface of the convection cooling structure, whereby the heat transfer to the environment is improved.

It is advantageous if at least one cooling rib is designed as indicated in claims 4 and 5, respectively.

Depending on the location of use of the luminous means, it can be advantageous if at least one cooling rib extends as described in claim 6.

A uniform outer contour of the convection cooling structure, which is advantageous for many applications, is achieved if this is designed as specified in claim 7.

Due to the alternative design of the convection cooling structure according to claim 8, the light can be adapted in shape individually to a particular environment of use.

It is favorable if the cooling fins have a radial extent related to the piston axis of the piston, as specified in claim 10.

In order to achieve the largest possible surface for a satisfactory heat transfer through the convection cooling structure, it is advantageous if this urafasst a specified in claim 11 number of cooling fins.

It is advantageous if the cooling fins have a thickness, as found in claim 12.

If at least one cooling rib is produced from a material named in claim 13, such a cooling rib serves also as a light guide, whereby the emission characteristic of the light source can be embossed. By the measure according to claim 14, the lighting effect of the light source can be adjusted in addition.

By the measure according to claims 15 and 16, a good heat dissipation from the semiconductor light-emitting chip through the interior of the light source is achieved to the outside to the convection cooling structure.

If the wavelength of the light emitted from the semiconductor light-emitting chip does not coincide with a desired wavelength, this can be adjusted by the measure according to claim 17. Phosphor particles absorb radiation impinging on them and emit radiation at least at a different wavelength. With a suitable choice of phosphor particles or phosphor particle mixtures, therefore, the radiation emitted by the semiconductor light-emitting chip can be converted into radiation with a different spectrum.

By the measure according to claim 18, a homogeneous distribution of the phosphor particles can be ensured in a simple manner. Due to the measures of claims 19 and 20, a heat dissipation from the semiconductor light-emitting chip via the first contact element is additionally ensured.

The measure according to claim 21 ensures that the light source can work together with standardized sockets.

Embodiments will be explained in more detail with reference to the drawings. In these show:

1 shows a side view of a lamp with a piston, which carries a convection cooling structure;

Figure 2 is a top view of the lamp of Figure 1;

Figure 3 is a section through the lamp of Figure 2 along the section line III-III;

Figure 4 is a section corresponding to Figure 3 through a lamp with a modified convection cooling structure;

FIG. 5 shows a section corresponding to FIG

Lamp with another modified

Convection cooling structure;

FIG. 6 shows a section corresponding to FIG

Lamp with yet another modified

Convection cooling structure;

FIG. 7 shows a section corresponding to FIG. 3 of a luminaire with a further modified convection cooling structure;

FIG. 8 shows a section of a luminaire corresponding to FIG. 3 with yet another modified one

Convection cooling structure;

FIG. 9 shows a section corresponding to FIG

Luminaire with a convection cooling structure, which corresponds to that of Figure 5, wherein the

Luminaire comprises two semiconductor light-emitting chips;

Figure 10 is a side view of a lamp with another embodiment of a convection cooling structure; Figure 11 is a top view of the lamp of Figure 10;

FIG. 12 shows a view corresponding to FIG. 11 of a luminaire with a further modified convection cooling structure, and

Figure 13 is a side view of a lamp with yet another modified convection cooling structure.

Figures 1 to 3 show a lamp 10 with a terminal socket 12, which is shown as a standard Edison screw base. Other standardized connection sockets, such as a bayonet base, a plug-in base, a glass squeeze base or the like can also be provided.

The connection base 12 carries a piston 14 designed as a hollow circular cylinder made of a light-transmitting material, such as an epoxy resin or glass, which has a peripheral wall 16 and an end wall 18. At its end adjacent to the terminal base 12, the piston 14 is open. The piston axis 20 of the piston 14 is shown in dashed lines in Figure 1. The peripheral wall 16 and the end wall 18 of the piston 14 together with the connection base 12 define an interior 22 in the piston 14.

As can be seen in particular in the section of FIG. 3, a first supply line 24 and a second supply line 26 run in the interior 22 of the piston 14, which regions extend in the interior of the terminal base 12 which is not recognizable, and with a reference number marked and in itself known external connection areas of the connection socket 12 are electrically connected.

In the interior 22 of the piston 14, the supply lines 24 and 26 contact a semiconductor light-emitting chip 28. For this purpose, the latter has a first contact surface 30 and a second contact surface 32, which are respectively connected to the first supply line 24 and the second supply line 26 of the light 10 ,

The semiconductor light-emitting chip 28 may comprise, for example, an n-type layer of n-GaN or also n-InGaN and a p-type layer of a III-V semiconductor material such as p-GaN, as is known per se. Between such an n-type and such a p-type

Layer may be arranged an MQW layer. MQW is the abbreviation for "Multiple Quantum Well". An MQW material is a superlattice which has an electronic band structure altered according to the superlattice structure and accordingly emits light at other wavelengths. The choice of the MQW layer can influence the spectrum of the radiation emitted by the p-n semiconductor light-emitting chip 28.

The interior 22 of the piston 14 is filled with a heat-conducting liquid in the form of silicone oil 34, which is indicated in the figures in the form of circles. By means of the silicone oil 34, heat generated by the semiconductor light-emitting chip 28 is dissipated to the peripheral wall 16 of the piston 14 and, moreover, to a convection cooling structure 36 connected to the outside of the bulb wall 16, which will be discussed in more detail below.

The p-GaN / n-InGaN semiconductor light emitting chip 28 irradiates ultraviolet light and blue when a voltage is applied Light in a wavelength range from 420 nm to 480 nm. In order to obtain a luminaire 10, which emits white light, with this semiconductor luminous chip 28, phosphor particles 38 are homogeneously distributed in the silicone oil 34 and are made of transparent solid state materials comprising color centers. In order to convert the ultraviolet and blue light emitted from the semiconductor light emitting chip 28 into white light, three types of phosphor particles 38 are used, which partially absorb the ultraviolet and blue light and emit themselves in yellow and red. If desired, you can also add phosphor particles that emit in the blue. The phosphor particles 38 are indicated in the figures as circles which are smaller than those circles which represent the silicone oil 34.

Alternatively, the phosphor particles may also be applied to the inner wall of the piston 14.

The convection cooling structure 36 acts as a passive heat sink and comprises in that shown in Figures 1 to 3

Embodiment a plurality of spaced-apart cooling fins, which each carry the reference numeral 40 and additionally a lowercase letter. The cooling ribs 40 have a central through-bore 42, wherein the through-bore 42a of the cooling rib 40a can be seen in FIG. The cooling fins 40 are formed as annular disks, wherein in the respective through hole 42 of a cooling fin 40 of the piston 14 of the lamp 10 extends. Whose peripheral wall 16 may be integrally connected to the respective cooling fins 40. However, it can also be glued to the respective cooling fins 40 by means of a thermally conductive adhesive.

The radial extent of the cooling ribs 40, which is related to the piston axis 20 of the piston 14, is shown in FIGS 3 for all cooling fins 40 the same size, so that the convection cooling structure 36 follows in its clear outer contour of a circular cylinder.

In Figures 4, 5, 6, 7 and 8 lights 10 are shown, which differ only in that they each carry a ^¬ weils modified convective cooling structure 36th In FIGS. 4, 5, 6, 7 and 8, components corresponding to components in FIGS. 1 to 3 bear the same reference numerals as in FIGS. 1 to 3.

In the case of the modified convection cooling structures 36 shown in FIGS. 4 and 5, the respective radial extent of a plurality of cooling fins 40, which relates to the piston axis 20 of the piston 14, varies in size.

In the exemplary embodiment of the convection cooling structure 36 of the luminaire 10 shown in FIG. 6, the radial extent of the cooling ribs 40 relative to the piston axis 20 of the piston 14 becomes larger in the direction of the piston axis 20 onto the connection base 12. The clear outer contour of the convection cooling structure 36 of Figure 6 corresponds to a cone. In the direction from the piston 14 to the connection base 12, the radial extent of the cooling rib 40 closer to the connection base 12 is greater than the corresponding extension of the immediately adjacent cooling fin 40, which, however, extends farther from the connection base 12 away; For example, see the cooling fins 4Oe and 40f in FIG. 6.

In the two further exemplary embodiments of the convection cooling structure 36 shown in FIGS. 7 and 8, the cooling fins 40 are not located substantially along the complete longitudinal extent, as in the exemplary embodiments of the convection cooling structure 36 shown in FIGS. 1 to 6. kung of the piston 14, but only over a portion of the same. In the exemplary embodiment of the convection cooling structure 36 according to FIG. 7, this region of the piston 14, which carries the cooling ribs 40, adjoins the connection base 12. In contrast, the region of the piston 14 with cooling fins 40 in the exemplary embodiment of the convection cooling structure 36 according to FIG. 8 is adjacent to the end wall 18 of the piston 14.

FIG. 9 shows a modified luminaire 10, in which two semiconductor luminescent chips 28, 28 'are provided, which are connected in series. In a further modification, more than two semiconductor light-emitting chips 28, 28 'may be provided in the interior 22 of the piston 14. A parallel connection of a plurality of semiconductor light-emitting chips 28, 28 'comes into consideration.

In the various exemplary embodiments of the convection cooling structure 36 shown in FIGS. 1 to 9, the cooling fins 40 are each arranged at an angle of 90 ° to the piston axis 22 of the piston 14.

FIGS. 10, 11, 12 and 13 show luminaires 10, which in each case only differ from the luminaires 10 in FIGS. 1 to 9 in that they each carry a modified convection cooling structure 44. In FIGS. 10, 11, 12 and 13, components corresponding to components in FIGS. 1 to 9 bear the same reference numerals as in FIGS. 1 to 9.

In addition to the possibility not shown, the cooling fins 40 at an angle greater than 0 ° and less than 90 °, ie obliquely to the piston axis 20 of the piston 14 to arrange, Figure 10 shows a convection cooling structure 44, wherein cooling fins 46 parallel to the piston axis 20 of the piston 14 in the Are arranged so that the cooling fins 46 radially project from the peripheral wall 16 of the piston 14 and each extending in a plane in which the piston axis 20 of the piston 14 is located. These cooling fins 46 are not formed as circular ring disks, but as viewed from above star-shaped cooling plates. The cooling fins 46 are also continuously provided with a lowercase letter.

The star-shaped arrangement of the cooling fins 46 can be clearly seen in the plan view of FIG. 11. In the convection cooling structure 44 shown in FIGS. 10 and 11, the radial extension of the cooling fins 46 relative to the piston axis 20 of the piston 14 is the same. However, as with the embodiments of the convection cooling structure 36 shown in FIGS. 4 to 8, the radial extent of a plurality of cooling fins 46, which is related to the piston axis 20 of the piston 14, can also vary in size for the convection cooling structure 44.

This is indicated in the exemplary embodiment of the convection cooling structure 44 according to FIG. 12 by dashed radially outer end regions 46 '. In addition, it can be seen there that more cooling fins 46 than in FIGS. 10 and 11 can be provided. This is angedeu ^¬ tet by further illustrated by dashed lines cooling fins, which were not specifically provided with a reference numeral.

In the embodiments of the convection cooling structure

44 according to FIGS. 10 to 12, the radially outer edge of the cooling ribs 46 runs in each case parallel to the piston axis 20 of the piston 14. FIG. 13 shows a further modification of the convection cooling structure 44. There, relative to the piston axis 20 of the piston 14 relative radial extent of several in the circumferential direction of the piston 14 successive Kühlrip- pen 46 in the direction of the piston axis 20 of the piston 14 to the terminal base 12 to larger. In other words, the outer edge of each cooling rib 46 extends obliquely to the piston axis 20 of the piston 14.

The following explanations apply equally to all exemplary embodiments shown in FIGS. 1 to 13.

The radial extension of the cooling fins relative to the piston axis 20 of the piston 14 is between 5.0 mm and 500.0 mm, preferably between 10.0 mm and 250.0 mm, preferably between 100.0 mm and 200.0 mm, especially preferably 150.0 mm. It is understood that the diameter of the piston 14 must be adapted to the selected radial extent of the cooling fins 40 and 46, respectively.

In the convection cooling structures 36 and 44 are each provided between 2 and 100, preferably 20 cooling fins. In the figures, for the sake of clarity, only a few cooling fins 40 and 46 are shown.

The cooling fins 40 and 46 are in the convection cooling structures 36 and 44 between 0.5 mm and 5.0 mm, preferably between 1.0 mm and 3.0 mm, more preferably 2.0 mm thick.

The cooling fins 40 and 46 are made of a translucent material, in particular of an epoxy resin or of glass. As a result, the cooling fins 40 and 46 act not only as cooling fins, but also as optical fibers, as a result of which a particular luminous characteristic can be given to the respective luminaire 10. This can be additionally done be reinforced that the cooling fins 40 of the convection cooling structure 36 and the cooling fins 46 of the convection cooling structure 44 have a reflection surface.

The first and second supply lines 24 and 26 are made of copper or aluminum. The first supply ^¬ line 24 forms a first electrode, and has an internal diameter of 1.0 mm to 3.0 mm, particularly of 2.0 mm. The first supply line 24 is shown in Figures 1 to 13 with a rectangular cross section; However, it can also be used a supply line 24 with a round cross-section. The second supply line 26 correspondingly forms a second electrode, but is smaller in its clear diameter with respect to the first supply line 24. Their diameter is only between 0.1 mm and 1, 0 mm.

As a result of the relatively thick first supply line 24, heat can be dissipated from the semiconductor luminescent chip 28 or 28 'via the first supply line 24 in the direction of the connection base 12.

Claims

claims

1. Lamp with

a) a piston (14) having a piston axis (20) which comprises a piston wall (16) made of translucent material which at least partially defines an internal space (22) of the piston (14);

b) a first contact element (24) and a second contact element (26), which can be acted upon by voltage and in the interior (22) of the piston (14) are arranged;

c) at least one semiconductor light-emitting chip (28, 28 ') which emits light upon voltage application and is connected to the first and the second contact element (24, 26),

characterized in that

d) the piston wall (16) is externally thermally conductively connected to a convection cooling structure (36, 44).

2. Lamp according to claim 1, characterized in that the convection cooling structure (36, 44) comprises at least one cooling fin (40, 46) which projects radially outwards from the piston wall (16).

3. Lamp according to claim 2, characterized in that the convection cooling structure (36, 44) a plurality

Cooling ribs (40, 46) which are spaced from each other and from the piston wall (16) project radially outward.

4. Lamp according to claim 2 or 3, characterized in that at least one cooling fin (40, 46) in

Circumferential direction around the piston wall (16) extends around.

5. Lamp according to one of claims 2 to 4, characterized in that at least one cooling fin (40) as

Annular ring disc (40) is formed.

6. Lamp according to one of claims 2 to 5, characterized in that at least one cooling fin (46) extends in a plane in which the piston axis (20) of the piston (14).

7. Lamp according to one of claims 2 to 6, characterized in that the convection cooling structure (36, 44) comprises a plurality of cooling fins (40, 46) whose on the piston axis (20) of the piston (14) related radial extent equal is.

8. Lamp according to one of claims 2 to 7, characterized in that the convection cooling structure (36,

44) comprises a plurality of cooling fins (40, 46) whose radial extent which is related to the piston axis (20) of the piston (14) is different.

9. Lamp according to claim 8, characterized in that on the piston axis (20) of the piston (14) related radial extent of a plurality of successive cooling fins (40, 46) in a direction of the piston axis (20) of the piston (14) increases.

10. Lamp according to one of claims 2 to 9, characterized in that on the piston axis (20) of the piston (14) related radial extent at least one Cooling fin (40, 46) between 5.0 mm and 500.0 mm, preferably between 10.0 mm and 250.0 mm, preferably between 100.0 mm and 200.0 mm, more preferably 150.0 mm.

11. Lamp according to one of claims 2 to 10, characterized in that the convection cooling structure (36, 44) between 2 and 100, preferably 20 cooling fins (40, 46) summarizes.

12. Lamp according to one of claims 2 to 11, characterized in that at least one cooling fin (40, 46) between 0.5 mm and 5.0 mm, preferably between 1.0 mm and 3.0 mm, more preferably 2.0 mm thick.

13. Lamp according to one of claims 2 to 12, characterized in that at least one cooling fin (40, 46), preferably all cooling fins, is made of a light-transmitting material, in particular of an epoxy resin or of glass.

14. Lamp according to one of claims 2 to 13, characterized in that the outer surface is at least one cooling fin (40, 46) is a reflection surface.

15. Lamp according to one of claims 1 to 15, characterized in that the interior space (22) of the piston (14) with a heat-conducting liquid (34) is filled.

16. Lamp according to claim 15, characterized in that the heat-conducting liquid (34) is silicone oil (34).

17. Lamp according to one of claims 1 to 16, characterized in that the semiconductor light chip (28, 28 ') at least partially substantially homogeneous distributed phosphor particles (38) is surrounded, which absorb light emitted by the semiconductor light-emitting chip (28, 28 ') and partially in complementary light, such that the lighting means (10) emits substantially white light altogether.

18. Lamp according to claim 17 with reference to claim 15 or 16, characterized in that the

Phosphor particles (38) in the heat-conducting liquid (34) are substantially homogeneously distributed.

19. Lamp according to one of claims 1 to 18, characterized in that at least one of the contact elements (24, 26) an electrode (24), in particular an electrode (24) made of copper or aluminum, is.

20. Lamp according to claim 19, characterized in that the first electrode (24) has a diameter of 1.0 mm to 3.0 mm, in particular of 2.0 mm.

21. Lamp according to one of claims 1 to 20, characterized in that the first contact element (24) and the second contact element (26) are connected to a connection socket (12).