FR3062455A1 - MOTOR VEHICLE PROJECTOR MULTI-SOURCE LIGHTING MODULE AND PROJECTOR - Google Patents

Abstract

The present invention relates to a lighting module (10) for a motor vehicle headlamp, comprising: - at least one first light source (20) semiconductor, capable of generating a first light radiation (24); - a device (17) for converting wavelength; and a mobile scanning mirror capable of reflecting an incident light beam towards said conversion device. The lighting module further comprises: at least one second light source (22) with semiconductors, capable of generating a second light radiation (26); and an optical collimation device (15, 115) capable of generating at least one light beam (40, 42, 154) from the first and second light rays, the mobile scanning mirror being arranged on a path of said at least one light bleam.

Description

Holder (s): folded.

VALEO VISION Joint-stock company simO Extension request (s):

Agent (s):

VALEO VISION Limited company.

FR 3 062 455 - A1 ® ASSOCIATED PROJECTOR MULTI-SOURCE LIGHTING MODULE.

@) The present invention relates to a lighting module (10) for a motor vehicle headlamp, comprising:

- at least a first light source (20) with semiconductors, capable of generating a first light radiation (24);

- a wavelength conversion device (17); and

- A mobile scanning mirror, capable of reflecting an incident light beam towards said conversion device.

The lighting module also includes:

- at least a second light source (22) with semiconductors, capable of generating a second light radiation (26); and

- an optical collimation device (15, 115) capable of generating at least one light beam (40, 42, 154) from the first and second light rays, the mobile scanning mirror being arranged on a path of said at least one light beam.

MOTOR VEHICLE PROJECTOR AND

Motor vehicle headlamp multi-source lighting module and associated headlamp

The present invention relates to a motor vehicle headlamp lighting module, of the type comprising: at least a first semiconductor light source, capable of generating a first light radiation; a wavelength conversion device; and a mobile scanning mirror, capable of reflecting an incident light beam towards said conversion device.

It is known to provide, at the front of a motor vehicle, headlights capable of forming light beams to fulfill various lighting functions, for example of the "main beam" or "low beam" type.

So-called adaptive light devices allow the intensity, dimensions and / or direction of the beams to be adjusted according to traffic conditions, in order to fulfill these various functions. Each projector generally comprises several lighting modules which make it possible to form a light beam from the projector. The modules can be switched on or off independently of each other to vary the characteristics of the beam in real time.

Lighting module means an assembly containing at least one light source and an optical projection or reflection system.

Lighting modules, as described in document EP2690352 in the name of the Applicant, include in particular light devices comprising light sources of the laser diode type, emitting in blue light, as well as a device capable of converting the laser radiation into a beam of white light. Such a conversion device is for example made up of phosphor elements.

The power of current laser diodes leads to equipping the lighting modules with several light sources in order to obtain sufficient intensity. However, mobile scanning mirrors require complex and expensive control electronics.

The object of the present invention is to improve the light output of existing lighting modules, without appreciable increase in manufacturing costs.

To this end, the subject of the invention is a lighting module of the aforementioned type, further comprising: at least one second semiconductor light source, capable of generating a second light radiation; and an optical collimation device capable of generating at least one light beam from the first and second light rays, the mobile scanning mirror being arranged on a path of said at least one light beam.

The same scanning mirror is thus associated with two distinct light sources.

According to other advantageous aspects of the invention, the lighting module comprises one or more of the following characteristics, taken in isolation or in any technically possible combination:

- the lighting module comprises first, second and third radiators, respectively coupled to the first and second light sources and to the conversion device;

- the lighting module comprises the same radiator coupled to both the first and second light sources;

the optical collimating device comprises a first and a second collimator, respectively capable of converting the first and the second light radiation into a first and into a second beam, the mobile scanning mirror being arranged on a trajectory of each of said first and second bundles;

each of the first and second light rays has a main direction of emission, said main directions forming an angle of less than 10 °, preferably less than 5 °;

- The optical collimation device comprises an optical fiber, said fiber comprising an input and an output, the first and second light rays being directed towards said input;

- The first and second light rays have the same wavelength, and the optical collimation device further comprises a polarization device interposed between the first and second light sources and the input of the optical fiber;

- The first and second light rays have different wavelengths, and the optical device further comprises a dichroic filter interposed between the first and second light sources and the input of the optical fiber;

- the lighting module also comprises an optical imaging system capable of projecting a light beam emitted by the wavelength conversion device.

The invention further relates to a motor vehicle headlamp comprising a lighting module as described above.

The invention will be better understood on reading the description which follows, given solely by way of nonlimiting example and made with reference to the drawings in which:

Figure 1 is a schematic view of a lighting module according to a first embodiment of the invention; and Figure 2 is a partial schematic view of a lighting module according to a second embodiment of the invention.

Figures 1 and 2 respectively represent a lighting module 10, 110 according to a first and a second embodiment of the invention. The lighting modules 10 and 110 will be described simultaneously below, the common elements being designated by the same reference numbers.

The lighting module 10, 110 is intended to be incorporated into a motor vehicle headlamp, said headlamp possibly comprising one or more other lighting modules.

The lighting module 10, 110 comprises a first 12 and a second 14 light devices, an optical collimation device 15, 115, a reflector device 16, a wavelength conversion device 17 and an optical system 18 of imagery. The conversion device 17 and the optical system 18 are not shown in FIG. 2.

Each of the first 12 and second 14 light devices comprises a light source 20, 22. Each of said light sources is capable of generating light radiation, respectively 24 and 26.

Each of the light sources 20, 22 is a semiconductor light source, more preferably a laser diode. In the embodiments of Figures 1 and 2, each of the light sources 20, 22 is a laser diode.

Each laser diode 20, 22 emits, for example, a visible beam whose wavelength is between 400 nm and 500 nm, preferably between 440 nm and 470 nm.

The light source 20, 22 of each of the first 12 and second 14 light devices is arranged along an emission axis, respectively 28 and 30, representing a main direction of emission.

Each of the first 12 and second 14 light devices further comprises a cooling device 32, 34, coupled to the light source 20, 22. The cooling device 32, 34 is for example a radiator.

In the embodiments of Figures 1 and 2, the cooling devices 32 and 34 are separate from each other. According to a variant not shown, the light sources of the first 12 and second 14 light devices are coupled to the same cooling device.

The optical collimation device 15, 115 is capable of generating at least one light beam from the light radiation 24, 26 from the light sources 20, 22.

In the embodiment of FIG. 1, the optical collimation device 15 comprises a first 36 and a second 38 collimators of the lens type. The first 36 and second 38 collimators are capable of converting the light radiation 24, 26 from the light source 20, 22, respectively from the first 12 and from the second 14 light devices, into a first 40 and into a second 42 beams. Preferably, the first 40 and second 42 beams have substantially convergent trajectories downstream of the collimators 36, 38.

In the embodiment of Figure 1, the emission axes 28 and 30 form an angle a preferably less than 10 °, more preferably less than 5 °. The light sources 20 and 22 are preferably placed at a short distance from each other, a minimum distance being in particular imposed by the size of the collimators 36, 38.

In the embodiment of FIG. 2, the optical collimation device 115 comprises an optical fiber 144, comprising an inlet 146 and an outlet 148. The optical device 115 further comprises a light coupling device 150, said coupling device 150 being interposed between the light sources 20, 22, on the one hand, and the input 146 of the optical fiber 144 on the other hand. The coupling device 150 is able to couple the light rays 24 and 26 at the input of the optical fiber 144.

The optical device 115 further comprises a lens type collimator 152, disposed at the outlet 148 of the optical fiber. The collimator 152 is capable of converting light radiation emerging from said outlet 148 into a third beam 154. The light radiation from said outlet 148 has the shape of a cone and is therefore easier to collimate than direct radiation from the two light sources 20 and 22.

According to a first variant of the embodiment of FIG. 2, the light rays 24 and 26 have the same wavelength, and the coupling device 150 is a polarization device. According to a second variant of the embodiment of FIG. 2, the light rays 24 and 26 have different wavelengths and the coupling device 150 is an optical coupler of the dichroic filter type.

Preferably, the optical fiber 144 has a low digital aperture. In particular, the digital aperture of the optical fiber 144 is preferably less than the digital aperture of the laser diodes 20, 22.

The digital aperture of an optical fiber characterizes the fiber acceptance cone: a light ray attempting to penetrate the fiber will be guided by total internal reflection only if it is coming from this cone.

The reflector device 16 comprises a scanning system 56 comprising at least one mirror, movable in one or two directions. The scanning system 56 can comprise several movable mirrors independently. The movement of the mirror (s) of the scanning system 56 is controlled by an electronic card 58. The scanning system 56 is in particular of the MEMS (microelectromechanical System) type.

The at least one mirror of the scanning system 56 is disposed on a path of the first 40 and second 42 beams of the module 10, or of the third beam 154 of the module 110. Said at least one mirror is able to reflect said one or more light beams to the conversion system 17.

The wavelength conversion device 17 comprises for example a plate 60 of a reflective substrate for laser radiation, on which is deposited a continuous and homogeneous layer 62 of phosphor. The plate 60 is for example made of aluminum.

Preferably, the conversion device 17 further comprises a radiator 64 coupled to the plate 60.

The phosphor layer 62 is arranged in a plane close to a focal plane of the optical system 18. Said optical system 18 comprises for example one or more lenses 66.

A method of operating the lighting module 10, 110 will now be described. When each of the diodes 20, 22 is supplied with electricity, it emits laser radiation sent to the optical collimation device 15, 115, then to the mirror or mirrors of the scanning system 56.

In the case of the lighting module 10 in FIG. 1, the areas of intersection of the first 40 and second 42 beams with said scanning system 56 are preferably close to one another, or even superimposed. Thus, the light intensities of the radiations of the two diodes 20, 22 add up.

In the case of the lighting module 110 in FIG. 2, a single beam 154 is obtained at the output of the optical fiber 144.

The scanning system 56 returns the said light beam (s) to the phosphor layer 62 of the conversion device 17. Depending on the displacement of the mobile mirror (s) of said scanning system 56, several points of the layer 62 therefore receive the laser radiation successively. diodes 20, 22.

In known manner, each point of the layer 62, receiving the monochromatic and coherent "blue" laser radiation, re-emits light considered to be "white", that is to say comprising a plurality of wavelengths between 400 nm and 800 nm approximately.

The optical imaging system 18 then infinitely forms an image of the light points of the phosphor layer 62, in the form of a light beam capable of illuminating the road in front of a vehicle.

The wavelength conversion process causes the plate 60 of the conversion device 17 to heat up. Furthermore, each diode 20, 22 emits heat. It is therefore advantageous to dissipate this heat by separate radiators 32, 34, 64.

Claims (10)

1, - Lighting module (10, 110) for a motor vehicle headlight, comprising: - at least a first light source (20) with semiconductors, capable of generating a first light radiation (24); - a device (17) for wavelength conversion; and - a mobile scanning mirror, capable of reflecting an incident light beam towards said conversion device; the lighting module being characterized in that it further comprises: - at least a second light source (22) with semiconductors, capable of generating a second light radiation (26); and - an optical collimation device (15, 115) capable of generating at least one light beam (40, 42, 154) from the first and second light rays, the mobile scanning mirror being arranged on a path of said at least one beam luminous. 2, - Lighting module according to claim 1, comprising a first (32), a second (34) and a third (64) radiators, respectively coupled to the first and second light sources and to the conversion device. 3, - Lighting module according to claim 1, comprising the same radiator coupled to both the first and second light sources. 4, - Lighting module (10) according to one of the preceding claims, in which the optical collimation device (15) comprises a first (36) and a second (38) collimators, respectively capable of converting the first (24 ) and the second (26) light rays in a first (40) and in a second (42) beams, the mobile scanning mirror being arranged on a path of each of said first and second beams. 5, - lighting module according to claim 4, wherein each of the first and second light rays has a main direction of emission (28, 30), said main directions forming an angle (a) less than 10 °, preferably less at 5 °. 6, - Lighting module according to one of claims 1 to 3, in which the optical collimation device (115) comprises an optical fiber (144), said fiber comprising an inlet (146) and an outlet (148), the first and second light rays being directed towards said entrance. 7, - Lighting module according to claim 6, in which: - the first (24) and second (26) light rays have the same wavelength, and - The optical collimation device further comprises a polarization device (150) interposed between the first and second light sources and the input (148) of the optical fiber. 8, - Lighting module according to claim 6, in which: - the first (24) and second (26) light rays have different wavelengths, and - The optical device further comprises a dichroic filter (150) interposed between the first and second light sources and the input (148) of the optical fiber. 9, - Lighting module according to one of the preceding claims, further comprising an optical imaging system (18) capable of projecting a light beam emitted by the device (17) for wavelength conversion. 10, - Motor vehicle headlamp, comprising at least one lighting module (10, 110) according to one of the preceding claims. 1/2