EP3990826A1

EP3990826A1 - Lighting device for vehicle with optimized heat exchange system

Info

Publication number: EP3990826A1
Application number: EP20736297.1A
Authority: EP
Inventors: Lotfi REDJEM SAAD; Maxime Rousseau; Benjamin PITON
Original assignee: Valeo Vision SAS
Current assignee: Valeo Vision SAS
Priority date: 2019-06-28
Filing date: 2020-06-29
Publication date: 2022-05-04
Also published as: FR3097940A1; CN114072615A; FR3097940B1; WO2020260723A1

Abstract

The present invention relates to a lighting module for a automotive vehicle comprising at least one first light source (10) and at least one electronic component. The lighting module further comprises at least one first heat sink (16) for dissipating heat generated by the at least one first light source (10) and at least one second heat sink (18) for dissipating the heat generated by the at least one electronic component. There is provided a heat exchange system for transferring heat away from the at least one first heat sink (16) and the at least one second heat sink (18). The heat exchange system comprises a blower (20), at least one first air channel (22) and at least one second air channel (24). The heat exchange system characterizes in that the at least one first air channel (22) and the at least one second air channel (24) have a common inlet portion, at least one first outlet portion (22a) and at least one second outlet portion (24a). The electronic component can be a micro-mirror device (14).

Description

LIGHTING DEVICE FOR VEHICLE WITH OPTIMIZED HEAT EXCHANGE

SYSTEM

TECHNICAL FIELD

The present invention relates to a lighting module for a lighting device of a automotive vehicle, the lighting module comprising an optimized heat exchange system. The invention also relates to an automotive vehicle lighting device comprising such a lighting module.

STATE OF THE ART

For the illumination of path of automotive vehicles, the use of lighting modules comprising a first light source associated to an electronic component is known. This electronic component can be chosen in the group consisting of: a second light source, of the light emitting diode kind (LED, pixelated LED, LED array, laser diode), a micro mirror device (MEMS or DLP type) or a controller of the first light source. A micro mirror device is an electromechanical micro system comprising one or two micro-mirror (MEMS type) or an array of of micro-mirrors (DLP or DMD type), which are all movable about the same axis and are capable of aligning at least two distinct orientations. The orientation of each micro-mirror can be controlled individually by the effect of an electrostatic force. The lighting module comprises a control circuit connected to an electronic control unit. The electronic control unit emits a control current for each of the micro-mirrors to define their orientation.

Such system along with light source such as LEDs makes it possible to create and project complex images in front of the vehicle. They are therefore used to perform various functions such as for example, a road lighting function to illuminate the path and also avoid dazzling other motorists, for example signaling functions or for example, projection of information useful for the safety of pedestrians located in the direct vicinity of the vehicle.

During the operation, such a lighting module can become very hot due to the use of LEDs and the micro mirror device. Excessive heating leads to malfunction or even destruction of the system and/ or the control circuit. To cool the first light source and the associated electronic component, for instance a micro-mirror device, the known use of heat sinks associated with blower fans are used. However, such cooling means are not always sufficiently efficient in maintaining the lighting module below a damaging temperature or are very complex.

SUMMARY OF THE INVENTION

An object of the present invention is to solve at least partially the disadvantages described above of known lighting module. In particular, it is the object of the present invention to provide a lighting module device with an improved and compact heat exchange system.

According to the embodiment of the present invention there is provided a lighting module for an automotive vehicle comprising at least one first light source and at least one electronic component. The lighting module further comprises a first heat sink for dissipating heat generated by the first light source and a second heat sink for dissipating the heat generated by electronic component. There is provided a heat exchange system for transferring heat away from the first heat sink and the second heat sink. The heat exchange system comprises a blower, a first air channel and a second air channel. The heat exchange system characterizes in that the first air channel and the second air channel have a common inlet portion, and respectively a first outlet portion and a second outlet portion.

In the scope of the invention, the first light source is preferably a light emitting diode (LED, laser diode, pixelated LED) or light emitting diode assembly (LED array) and the electronic component that is associated with said first light source is chosen in the group consisting of: a second light source, of the light emitting diode kind (LED, pixelated LED, laser diode, LED array), a micro mirror device (MEMS or DLP type) or a controller of the first light source.

According to a non limiting embodiment of the present invention, the blower of the heat exchange system is assembled at the common inlet portion of the first air channel and the second air channel. And, the axis of the blower is offset from the first heat sink and the second heat sink. According to a no limiting embodiment of the present invention, the first air channel of the heat exchange system directs the air from the blower to the first heat sink and the second air channel of the heat exchange system directs the air from the blower to the second heat sink.

According to a no limiting embodiment of the present invention, wherein the second air channel for the second heat sink comprises multiple sections.

According to a no limiting embodiment of the present invention, the air in the first air channel flows across the top of first heat sink the air in the second air channel flows across the bottom of second heat sink.

According to a no limiting embodiment of the present invention, the first air channel and the second air channel creates two separate air flows towards the first heat sink and the second heat sink.

BRIEF DESCRIPTION OF THE INVENTION

To complete the description and to provide a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate an embodiment of the invention, which should not be construed as restricting the scope of the invention, but only as an example of how the invention can be carried out. The drawings comprise the following characteristics.

Figure 1 shows a perspective view of a lighting module comprising heat exchange system and a projector lens.

Figure 2 is a perspective view of the lighting module showing the blower, air channels and partially showing the internal components such as micro mirror and heat sink.

Figure 3 is another view of the lighting module shown in Figure 1 , the figure depicts the arrangement of the air channel with respect to the system. Figure 4 is a cut section of Figure 3, the Figure shows arrangement of the light source and the micro mirror device in the system. The Figure further depicts the air flow direction in the device from the blower.

Figure 5 shows the arrangement of air channels along with fins as per the embodiment of the present invention.

Figure 5a shows the air channel and the heat sink arrangement of figure 5 for the light source of the lighting device.

Figure 5b shows the air channel and the heat sink arrangement of figure 5 for the micro mirror device. The figure further shows the fins and the air outlet as per the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 1 shows a perspective view of a lighting module comprising a light source such LEDs along with a projector lens and a heat exchange system, according to an embodiment of the present invention.

According to an embodiment of the present subject matter, the lighting module (100) shown in Figure 1 comprises a first light source (not shown) along with a projector lens (12) for lighting the path ahead of the automotive vehicle. In such lighting module to avoid component failure due to heat generation, the lighting module (100) of present subject matter is provided with a heat exchange system for reducing heat generated inside the module.

Figure 2 shows partially the internal component of the lighting module (100). The lighting module (100) as per the embodiment of the present invention comprises, at least one first light source (10) (not visible in figure) and at least one micro mirror device (14), that takes here the form of a micro-mirror array (DLP type). This micro-mirror device (14) is here one embodiment of the electronic component to which the first light source can be associated in the scope of the invention. The module further comprises at least one first heat sink (16) for dissipating heat generated by the at least one first light source (10) and at least one second heat sink (18) for dissipating the heat generated by the electronic component (the micro-mirror device (14) according to shown embodiment). The module is provided with a heat exchange system for transferring heat away from the at least one first heat sink and the at least one second heat sink. The heat sink of the present invention comprising a blower (20), at least one first air channel (22) and at least one second air channel (24)., The at least one first air channel (22) and the at least one second air channel (24) of the present invention have a common inlet portion, at least one first outlet portion (22a) and at least one second outlet portion (24a).

Figure 3 shows another view of the lighting module shown in Figure 1 ; the figure depicts the arrangement of the air channel with respect to the system. Figure 4, is a cut section of the Figure 3 showing the first light source (10) and the at least one first heat sink (16) of the first light source (10). The figure further shows the associated electronic component under the embodiment of a micro mirror array (14) and its corresponding at least one second heat sink (18). The figure additionally, shows the blower (20), at least one first air channel (16) and at least one second air channel (18) of the heat exchange system.

According to the embodiment of the present invention, the blower (20) of the heat exchange system is assembled at the common inlet portion of the at least one first air channel (22) and the at least one second air channel (24). The blower of the present invention is an axial fan, but it is understood that any type of such as centrifugal fan, radial fan or any other fan can be adapted without deviating from the scope of the study. The blower (20) provided at the common inlet portion of the at least one first air channel (22) and the at least one second air channel (24) is arranged such that the axis of the blower is offset from the at least one first heat sink and the at least one second heat sink. The above signifies that the blower (20) is not placed directly above the at least one first heat sink and the at least one second heat sink. The arrangement ensures that equal amount of flows to the at least one first air channel (22) and the at least one second air channel (24). The heat exchange system is arranged such that the at least one first outlet (22a) of the at least one first air channel (22) is provided at the front and is oriented upwards. The at least one second air channel (24) for the at least one second heat sink (18) comprises multiple sections, wherein the first section project vertically downwards from the common inlet portion and the second section bends towards the bottom of the at least one second heat sink (18). The at least one first air channel (22) of the heat exchange system directs the air from the blower (20) towards the at least one first heat sink (16) and the at least one second air channel (24) of the heat exchange system directs the air from the blower (20) to the at least one second heat sink (1 8). Due to the above design of the heat exchange system of the lighting device (100) the at least one first air channel (22) and the at least one second air channel (24) creates two separate air flows towards the at least one first heat sink (16) and the at least one second heat sink (18). The arrangement makes sure that the hot air from the at least one first air channel (22) is not passed to the at least one second air channel (24) and vice versa as the first light source (10) is arranged above the associated electronic component (here, the micro mirror device (14)).

Figure 5 shows the air channels along with the fins for the first light source and the micro mirror device as per the embodiments of the present invention. The figure shows the at least one first air channel (22) and at least one second air channel (24) of the heat exchange system. There is provided an opening (22”) in the at least one first air channel (22) to accommodate the blower (20) (not shown). The at least one first air channel (22) includes fins (26a) along its length towards the at least one first outlet portion (22a) to help in heat dissipation. The at least one second air channel (24) starts at the end opposite to the first outlet portion (22a) of the at least one first air channel (22). The at least one second air channel (24) is formed of two sections, one section at the bottom of the heat exchange system opposite to the at least one first air channel (22) and the other section connecting the bottom portion of the at least one second air channel (24) and the at least one first air channel (22). The at least one second air channel (24) includes fins (26b). There is provided a wall (30) which channels the air along the bottom portion of the at least one second air channel (24). The at least one second air channel is provided with at least one second outlet portion (24a) towards the bottom of the heat exchange system (as shown in Figure 4). The at least one second outlet portion directs the heat away from the heat exchange system ensuring better efficiency.

Figure 5a shows the arrangement of the at least one first air channel (22) on the at least on first heat sink (16). The figure also shows the arrangement of the first light source (10) in relation to the at least one first heat sink. As shown in the Figure, the at least one first air channel (22) for the at least one first heat sink (16) comprises of multiple fins (26a) running through the at least one first air channel. Due to the arrangement of the at least one first air channel (22) and the offset blower (20) arrangement the air in the at least one first air channel (22) flows across the top of at least one first heat sink (16) and exists from the at least one first outlet (22a).

Similarly, Figure 5b shows the second section of the at least one second air channel (24). Flere, the arrangement of the micro mirror device (14) in relation to the at least one second air channel (24) is shown. The at least one second air channel (24) for the at least one second heat sink (18) comprises multiple fins (26b) running across the second section and the at least one second outlet (24a) towards the bottom of the at least one second (24) air channel. The air in the at least one second air channel (24) flows across the bottom of at least one second heat sink (18) and exists from the at least one second outlet (24a). There is provided a wall (30) to help streamline the airflow across the at least one second air channel (24).

In accordance with the present invention, due to the position of the blower (20) and separate air channels, namely the at least one first air channel (22) and the at least one second air channel (24) dedicated for the respective at least one first heat sink (16) and at least one second heat sink (18) heat transfer from the hot zones is effective and fast. Also, the fins which are made of Aluminum (but can be any other material of similar properties) ensure better heat convection and transfer. It is understood that possible variations of the present invention is possible (such as changing the profile of air channel, blower type and material) without deviating from the scope of the invention.

Claims

Claims:

1. A lighting module (100) for a automotive vehicle comprising:

at least one first light source (10) and at least one electronic component;

at least one first heat sink (16) for dissipating heat generated by the at least one first light source (10);

at least one second heat sink (18) for dissipating the heat generated by the at least one elctronic component;

a heat exchange system for transferring heat away from the at least one first heat sink (16) and the at least one second heat sink (18) comprising:

a blower (20),

at least one first air channel (22) and at least one second air channel (24), wherein the at least one first air channel (22) and the at least one second air channel (24) have a common inlet portion, at least one first outlet portion (22a) and at least one second outlet portion (24a).

2. The lighting module as claimed in claim 1 , wherein the blower (20) of the heat exchange system is assembled at the common inlet portion of the at least one first air channel (22) and the at least one second air channel (24).

3. The lighting module as claimed in claim 1 or 2, wherein the blower (20) is an axial fan.

4. The lighting module as claimed in any of the preceding claims, wherein the axis of the blower (20) is offset from the at least one first heat sink (16) and the at least one second heat sink (18).

5. The lighting module as claimed in any of the preceding claims, wherein the at least one first air channel (22) of the heat exchange system directs the air from the blower (20) to the at least one first heat sink (16) and the at least one second air channel (24) of the heat exchange system directs the air from the blower (20) to the at least one second heat sink (18).

6. The lighting module as claimed in any of the preceding claims, wherein the at least one first air channel (22) for the at least one first heat sink (16) comprises of multiple fins running through the at least one first air channel (22).

7. The lighting module as claimed in any of the preceding claims, wherein the at least one first outlet (22a) of the at least one first air channel (22) is provided at the front and is oriented upwards.

8. The lighting module as claimed in any of the preceding claims, wherein the at least one second air channel (24) for the at least one second heat sink (18) comprises multiple sections, wherein the first section project vertically downwards from the common inlet portion and the second section bends towards the bottom of the at least one second heat sink (18).

9. The lighting module as claimed in any of the preceding claims, wherein the at least one second air channel (24) for the at least one second heat sink (18) comprises multiple fins running across the second section; and the at least one second outlet (24a) is oriented towards the bottom of the at least one second air channel (24).

10. The lighting module as claimed in any of the preceding claims, wherein the air in the at least one first air channel (22) flows across the top of at least one first heat sink (16).

1 1 . The lighting module as claimed in any of the preceding claims, wherein the air in the at least one second air channel (24) flows across the bottom of at least one second heat sink (18).

12. The lighting device as claimed in any of the preceding claims, where in the at least one first air channel (22) and the at least one second air channel (24) creates two separate air flows towards the at least one first heat sink (16) and the at least one second heat sink (18).

13. Lighting module as claimed in any of the preceding claims, characterized in that the at least one first heat sink (16) is arranged above the at least one second heat sink (18).

14. Lighting module as claimed in any of the preceding claims, wherein the at least one first light source (10) comprises at least one light emitting diode.

15. Lighting module as claimed in claim 1 , characterized in that the electronic component is a micro-mirror device (14) and in that it comprises a projection lens (12) capable of guiding light rays emitted by the at least one first light source (10) and reflected by the micro-mirror device (14).