RETROFIT LAMP

Abstract

A retrofit lamp (1) comprises a heat sink (8), a light source module (10) with a circuit board (11), whose rear side lies two-dimensionally on the heat sink (8) and at the front side of which at least one semiconductor light source (12) is arranged, and a ring (6) partially covering the front side of the light source module (10), wherein the ring (6) presses the light source module (10) onto the heat sink (8). A method serves for producing a retrofit lamp (1), wherein the rear side of the circuit board (11) of the light source module (10) is laid on the heat sink (8) and the ring (6) is put on the retrofit lamp (1) from the front such that it presses the light source module (10) onto the heat sink (8). The invention is particularly applicable to LED retrofit lamps for replacing conventional light bulbs or halogen lamps.

Claims

1. A retrofit lamp, comprising a heat sink, a light source module with a circuit board whose rear side lies two-dimensionally on the heat sink and at the front side of which at least one semiconductor light source is arranged, and a ring partially covering the front side of the light source module, wherein the ring presses the light source module onto the heat sink

2. The retrofit lamp according to claim 1, wherein the ring is locked with the heat sink.

3. The retrofit lamp according to claim 1, wherein the ring comprises inwardly directed, elastically flexible pressing tabs resting on the front side of the light source module.

4. The retrofit lamp according to claim 3, wherein the pressing tabs, at their side facing the light source module, comprise at least one projection resting on the front side of the light source module.

5. The retrofit lamp according to claim 3, wherein the pressing tabs are uniformly arranged in an angle-offset manner in circumferential direction.

6. The retrofit lamp according to claim 3, wherein the ring has a vertical sidewall to which the pressing tabs are joined protruding inwards at the front.

7. The retrofit lamp according to claim 1, wherein the ring consists of fiber reinforced plastics.

8. The retrofit lamp according to claim 1, wherein the ring is configured for locking with at least one optical element.

9. The retrofit lamp according to claim 1, wherein the light source module is connected with the heat sink without an adhesive.

10. A method for producing a retrofit lamp according to claim 1, wherein the rear side of the circuit board of the light source module is laid on the heat sink and then the ring is put on the retrofit lamp from the front such that it presses the light source module onto the heat sink.

Description

[0032] The above-described characteristics, features and advantages of this invention as well as the way in which these will be achieved become more obvious and clearer in connection with the following schematic description of an embodiment which will be explained in more detail in connection with the drawings. Same elements or elements with the same effects may be provided with the same reference numbers for the sake of clarity.

[0033] FIG. 1 shows a retrofit lamp for replacing a conventional light bulb in an oblique view;

[0034] FIG. 2 shows the retrofit lamp in a cross-sectional oblique view;

[0035] FIG. 3 shows an exploded view of the retrofit lamp without a bulb in an oblique view;

[0036] FIG. 4 shows a ring of the retrofit lamp in an oblique view;

[0037] FIG. 5 shows a section of the retrofit lamp without a bulb and without a lens in an assembled state in an oblique view from the front; and

[0038] FIG. 6 shows a section of the retrofit lamp without a bulb and without a lens in the region of the ring in a cross-sectional side view.

[0039] FIG. 1 shows a retrofit lamp 1 for replacing a conventional light bulb in an oblique view. At its rear end the retrofit lamp 1 with longitudinal axis L comprises an Edison base 2 (e.g. of type E27). A jacket 3, e.g. of plastics, supporting or holding a translucent bulb 4 at the front joins the Edison base 2 in a forward direction. The bulb 4 arches over a translucent optical element (“lens” 5) as well as a ring 6 supporting or holding the lens 5. The bulb 4 can be transparent or diffusely scattering.

[0040] FIG. 2 shows the retrofit lamp 1 in a cross-sectional oblique view. The jacket 3 laterally surrounds a driver housing 7, 8 in which a driver 9 is accommodated. The driver housing 7, 8 comprises a cup-shaped lower part 7 at base side and a cup-shaped lid at front side serving as a heat sink 8. The lower part 7 may consist of metal or plastics. Here, the heat sink 8 consists of metal, e.g. of aluminum.

[0041] A LED module 10 abuts an outside planar contact area of the heat sink 8 oriented forward.

[0042] FIG. 3 shows an exploded view of the retrofit lamp 1 without a bulb 4 in an oblique view. The LED module 10 comprises a circuit board 11 which lies two-dimensionally on the heat sink 8 at its rear side and is equipped with several light-emitting diodes (LEDs) 12 at its front side.

[0043] The ring 6 shown in FIG. 4 alone in an oblique view comprises a circular ring-shaped vertical sidewall 13 to which four resilient pressing tabs 14 are joined in a forward direction or at the front side (and hence in a main emitting direction of the LEDs 12). Extending from the sidewall 13, the pressing tabs 14 extend firstly inclined and radially inward (towards the longitudinal axis L coinciding with a symmetry axis of the ring 6) and then approximately horizontally (and thus parallel to the circuit board 11) inward. Thus, the pressing tabs 14 protrude inward at the front side. The pressing tabs 14 are uniformly arranged in an 90° angle-offset manner to each other in a circumferential direction about the longitudinal axis L.

[0044] The pressing tabs 14 have bulging contact projections 15 at the side facing the LED module 10 or the circuit board 11. The contact projections 15 rest on the front side of the circuit board 11 and press it against the heat sink 8. For this purpose, the pressing tabs 14 are arranged above the circuit board 11 or cover it there. As the LEDs 12 are arranged centrally on the circuit board 11, the pressing tabs 14 press onto the circuit board 11 at the edge.

[0045] Furthermore, between the pressing tabs 14 the ring 6 comprises four fastening tabs 16 which also extend firstly inclined inward, extending from the sidewall 13, and then horizontally inward. The pressing tabs 14 and the fastening tabs 16 are alternately arranged in circumferential direction. The fastening tabs 16 comprise no contact projections 15, but rather inside insertion recesses 17.

[0046] Furthermore, at the inside of its sidewall 13 the ring 6 comprises several, locking projections 18 distributed in circumferential direction.

[0047] Now referring to FIG. 3, at its sidewall the heat sink 8 comprises several locking recesses 19 matching the locking projections 18 of the ring 6 such that the ring 6 is put on the heat sink 8 and can be locked with it by an engagement of the locking projections 18 with the locking recesses 19.

[0048] At its rear lower side the lens 5 comprises locking hooks 20 matching the insertion recesses 17 to be fastened at the ring 6 in a locking manner.

[0049] FIG. 5 shows a section of the retrofit lamp 1 without the bulb 4 and without the lens 5 in an assembled state in an oblique view from the front. With their contact projections the pressing tabs 14 press onto the circuit board 11 because they have been bent away from the circuit board 11 when the ring 6 was put onto the heat sink 8. FIG. 6 shows a section of the retrofit lamp 1 without the bulb 4 and without the lens 5 in the region of the ring 6 in a cross-sectional side view. The pressing tabs 14 are shown in their state where they are not being bent. In order to put them into the bent state, here a displacement b of about 0.5 mm is necessary.

[0050] Due to the bending of the pressing tabs 14 an elastic restoring force is generated at each of the pressing tabs 14 which effects a pressing force F (see FIG. 5) onto the circuit board 11 which is well selectable. For being able to generate a sufficiently high elastic restoring force over a long period, the ring 6 here consists of glass-fiber reinforced plastics. Particularly, the pressing force F is so high that the LED module 10 can be connected to the heat sink 8 without an adhesive.

[0051] Furthermore, FIG. 5 shows electrical connections 21 between the driver 9 and the LED module 10. The driver 9 can be supplied with electrical energy through the Edison base 2 and transforms the electrical energy into electrical signals for operating the LEDs 12 which can propagate via the electrical connections 21 to the circuit board 11 and then to the LEDs 12.

[0052] Although the invention was illustrated and described in detail by the shown embodiment, the invention is not limited thereto, and other variations can be derived therefrom by those skilled in the art without leaving the scope of the invention.

[0053] Generally, “a”, “an” etc. may be understood as singular or plural, in particular in terms of “at least one” or “one or more” etc., as long as this is not excluded explicitly, e.g. by the term “exactly one” etc.

[0054] Numerical data may also include the given number exactly as well as a usual tolerance range as long as this is not excluded explicitly.

REFERENCE NUMERALS

[0055] retrofit lamp 1

[0056] Edison base 2

[0057] jacket 3

[0058] bulb 4

[0059] lens 5

[0060] ring 6

[0061] lower part of driver housing 7

[0062] heat sink 8

[0063] driver 9

[0064] LED module 10

[0065] circuit board 11

[0066] light-emitting diodes 12

[0067] sidewall of the ring 13

[0068] pressing tab 14

[0069] contact projection 15

[0070] fastening tab 16

[0071] insertion recess 17

[0072] locking projection nose 18

[0073] locking recess 19

[0074] locking hook 20

[0075] electrical connection 21

[0076] displacement b

[0077] pressing force F

[0078] longitudinal axis L