Lighting module for automotive vehicle comprising two types of light sources

Abstract

A lighting module for an automotive vehicle. The module comprises a support, for example made by a heat dissipation device, and a printed circuit board accommodating at least one light source of a first type. The printed circuit board is housed on the support. The lighting module proposes allowing light sources of a second type, generating, for example, a different amount of heat, to be housed so that the rays arising from the two types of sources may be coupled into one and the same light guide, while efficiently dissipating the heat generated by each of the types of light sources.

Claims

1. A lighting module for an automotive vehicle, comprising: a support including heat dissipation elements, the support comprising a first generally planar surface; a light guide; at least one light source of a first type; at least one light source of a second type; and a printed circuit board accommodating the at least one light source of a first type, the printed circuit board comprising an edge and being in direct contact with the first planar surface, wherein the arrangement of the at least one light source of the first type and the second type is such that the at least one light source of the first type and the at least one light source of the second type are configured to emit light rays in the direction of an entry face of the light guide of the lighting module, the at least one light source of the first type generates less heat than the at least one light source of the second type, the at least one light source of the second type is in direct contact with the first planar surface and is housed on the support adjacent to the edge of the printed circuit.

2. The lighting module according to claim 1, wherein the at least one light source of the second type is electrically connected to the printed circuit board.

3. The lighting module according to claim 2, wherein a connection between the at least one light source of the second type and the printed circuit board is made via bridging by a metal wire.

4. The lighting module according to claim 2, wherein the at least one light source of the first type and of the second type are supplied with electricity by shared means for controlling the power supply.

5. The lighting module according to claim 1, wherein the at least one light source of the first type and of the second type are supplied with electricity by shared means for controlling a power supply.

6. The lighting module according to claim 1, wherein the printed circuit board is fixed to the support by crimping or by bonding.

7. The lighting module according to claim 1, wherein the light source of the second type is fixed to the support by bonding.

8. The lighting module according to claim 7, wherein the bonding is carried out using a thermally conductive adhesive.

9. The lighting module according to claim 1, wherein the heat dissipation elements comprise aluminum.

10. The lighting module according to claim 1, wherein the at least one light source of the first type emits light of a first color and the at least one light source of the second type is emits light of a second color.

11. The lighting module according to claim 1, wherein the at least one light source of the first type is intended to carry out a first lighting function, and the at least one light source of the second type is intended to carry out a second lighting function.

12. The lighting module according to claim 11, wherein the at least one light source of the first type is a turn indicator configured to operate intermittently and at least one light source of the second type is a daytime running light.

13. The lighting module according to claim 1, wherein the at least one light source of the first type and the second type are semiconductor element light sources.

14. The lighting module according to claim 1, wherein the at least one light source of the first type and the second type and the light guide are arranged so that the at least one light source of the first type emits light rays in the direction of a first entry face of the light guide, and so that the at least one light source of the second type emits light rays in the direction of a second entry face, different from the first entry face, of the same light guide.

15. The lighting module according to claim 1, wherein the at least one light source of the first type and the second type and the light guide are arranged so that the at least one light source of the first and of the second type emit light rays in the direction of the same entry face of the light guide.

16. The lighting module according to claim 15, wherein the at least one light source of the first type and the second type are light-emitting diode (LED) light sources.

17. The lighting module according to claim 1, wherein the at least one light source of the first type emits an amber color and the at least one light source of the second type emits a white color.

Description

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

(1) Other features and advantages of the present invention will be better understood with the aid of the description and the drawings, in which:

(2) FIG. 1 shows a schematic illustration of a lateral cross section through a module according to one preferred embodiment of the invention;

(3) FIG. 2 shows a schematic illustration of a top view of a module according to one preferred embodiment of the invention; and

(4) FIG. 3 shows a schematic illustration of a lateral cross section through a module according to one preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) In the following description, similar reference numerals are used to describe similar concepts across the various embodiments of the invention. Thus, the reference numerals 100, 200 describe a lighting module in two different embodiments according to the invention.

(6) Unless specified otherwise, technical features that are described in detail for one given embodiment may be combined with the technical features that are described in the context of other embodiments described by way of non-limiting example.

(7) The elements shown in the drawings are not to scale and are simplified in order to enhance the clarity of the account.

(8) FIG. 1 shows, in a schematic lateral cross section, a lighting module 100 according to the invention, in which only the components that relate directly to the invention are shown. A printed circuit board 120 accommodates an electronic circuit additionally comprising at least one light source 130. The light source 130 is of a first type and it is, for example, a light-emitting diode (LED).

(9) The printed circuit board 120 is housed on a support 110 of the lighting module 100. At least one light source, for example of LED type, of a second type 140, is positioned directly on a surface of the support 110, and not on the printed circuit board 120. The printed circuit board 120 comprises a through-window 122 or a bay cut out of one of its edges, so that the substrate of the printed circuit board 120 at least partially surrounds the light sources of the second type 140. The light sources of the first type 130 and of the second type 140 may, for example, differ in the color of the light emitted, or in the lighting function that they are intended to carry out within the lighting module 100. Combinations of these differences and other distinctive attributes are conceivable without departing from the scope of the invention.

(10) The lighting module 100 also comprises a light guide 150 that comprises an entry face 152, intended to couple light rays incident thereto, and to guide them toward an exit face (not illustrated). Such light guides 150 are known in the art; they may, for example, comprise multiple entry faces. The light rays are guided inside the light guide 150 by means of the principle of total reflection off the internal walls of the light guide 150. A light guide 150 allows, in particular, light rays to be emitted at a location a distance away from the light source 130, 140 from which they arise. According to the invention, the arrangement of the light sources 130, 140 is such that the light sources of the first type 130, housed on the printed circuit board 120, and the light sources of the second type 140, housed on the support 110, are capable of emitting light rays in the direction of an entry face 152 of the light guide 150.

(11) The printed circuit board (PCB) 120 is preferably a circuit printed on a generally planar and rigid substrate. The substrate is, in a known manner, fashioned from an epoxy resin. The through-window or bay 122 may be incorporated during the injection molding of the substrate or, alternatively, it may be made by removing the corresponding material once the substrate has been produced. The printed circuit board 120 may alternatively be a flexible printed circuit board (FPCB) or a printed circuit board with a complex geometry of MID (molded interconnect device) type.

(12) The top view of FIG. 2 shows the example of the through-window or bay 122 surrounding a light source 140 of the second type, positioned on the support 110. Advantageously, the support 110 is a heat dissipation element, preferably made of aluminum, and comprises a generally planar surface to which the printed circuit board 120 and the light sources 140 of the second type are fixed. The fixing is, for example, achieved using a thermal adhesive. The printed circuit board 120 may alternatively be fixed to the heat dissipation element by crimping, by means of crimping pins provided for this purpose on the surface. The heat dissipation element is, for example, a radiator.

(13) In one preferred non-limiting embodiment, the light sources of the first type 130 are LEDs that are able to emit amber-colored light. These light sources 130 carry out the function of blinker, or turn indicator, of an automotive vehicle and therefore operate only intermittently, thus generating relatively little heat. The light sources of the second type 140 are LEDs that are able to emit white-colored light. These light sources 140 carry out, for example, the function of daytime running lights and generate a more substantial amount of heat over extended periods of time. The invention allows these light sources 140 to be positioned in direct contact with the heat dissipation element or support 110, thus guaranteeing an effective exchange of heat, while all of the other electronic components may be housed on the printed circuit board 120, thereby facilitating their placement when manufacturing the lighting module 100. The two types of light sources 130, 140 may nonetheless be positioned so as to be physically close to one another, so that the light rays arising from the two types of light sources 130, 140 may be coupled into one and the same light guide 150, even though the area of its entry face 152 does is not substantial. This has advantages in terms of saving space within the lighting module 100, allowing advantageous designs to be produced. Specifically, depending on the chosen lighting function, one and the same exit face of the light guide 150 may emit either white light rays or amber-colored light rays.

(14) In one preferred embodiment, the light sources of the first and of the second type 130, 140 are supplied with electricity by a shared circuit for controlling the power supply. The electronic components making up this circuit may be housed on the printed circuit board 120, or on a printed circuit board physically located a distance away from the printed circuit board 120 and connected thereto by conductive wires. In order to achieve this configuration, the light sources of the second type 140 are advantageously electrically connected to an electronic circuit housed on the printed circuit board 120.

(15) FIG. 3 shows one particular preferred embodiment of the lighting module 200 according to the invention in schematic lateral cross section. A printed circuit board 220 accommodates an electronic circuit additionally comprising at least one light source 230. The printed circuit board 220 is housed on a support 210 of the lighting module 200. At least one light source of a second type 240 is positioned directly on a surface 212 of the support 210. The printed circuit board 220 comprises a through-window 222, so that the substrate of the printed circuit board 220 at least partially surrounds the light sources of the second type 240. The lighting module 200 also comprises a light guide 250 that comprises an entry face 252, intended to couple light rays incident thereto, and to guide them.

(16) The light-emitting diodes or light sources 240 of the second type are electrically connected to the electronic circuit of the printed circuit board 220 via metal wires 260 forming bridges between contact lands of the printed circuit board 220 on the one hand, and corresponding contact lands of the diodes or light sources 240. These wires 260 are soldered to these lands using ultrasound. This technique is commonly referred to as “wire bonding” or “bridging”. It is a technique commonly used for making the electrical connections between the package and the chip of an integrated circuit. The bond is simply achieved via a wire (or bridge) soldered between the two connection pads that are provided for this purpose on each of the elements. The soldering is generally carried out using ultrasound. The material of the wire is aluminum, gold or copper. The diameter of the wire may be between 75 μm and 250 μm.

(17) The wire bonding technique facilitates the placement of the various components when manufacturing the lighting module 200. In a first step, the light sources of the second type 240 are positioned on and fixed to the support 210, which is preferably a heat sink. Next, the printed circuit board 220, populated with electronic components beforehand, including light sources of the first type 230, is positioned on and fixed to the support 210. The arrangement is such that the through-bay or window 222 of the printed circuit board 220 surrounds the location of the light sources 240 of the second type. Next, the electrical connection between the light sources 240 of the second type and the printed circuit board 220 is made via bridging.

(18) While the system, apparatus, process and method herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise system, apparatus, process and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.