LIGHT MODULE FOR A MOTOR VEHICLE INCLUDING A SEMICONDUCTOR LIGHT SOURCE

A light module including a semiconductor light source, an optical reflector that is positioned with respect to the light source, and a reference surface, belonging to a heat sink radiator, on which the light source and the optical reflector are fastened, wherein the light source is supported by a mount that is fastened on the reference surface. The light module includes means for adjusting the position of the mount with respect to the reference surface and means for fastening the mount, in the adjusted position, on the reference surface.

TECHNICAL FIELD OF THE INVENTION

The invention relates to a light module used in the field of lighting and/or light signalling, in particular for a motor vehicle.

The invention relates more particularly to a light module including at least one semiconductor light source that is associated with an optical component that is positioned with precision with respect to the light source, in particular in order to receive radiation from the at least one light source.

TECHNICAL BACKGROUND OF THE INVENTION

The invention relates more particularly to a light module of the type mentioned above in which the light source and the optical component—such as for example an optical reflector, an optical collimator or an optical lens—are positioned indirectly with respect to one another by each being positioned and fastened with precision on a common reference surface belonging for example to a radiator belonging to the light module.

Such precise positioning is particularly important in the case of one or more semiconductor light source(s), and more particularly in the case of what is termed a laser light source.

The light source has to be positioned with small dimensional tolerances in the three axes, in particular of less than 1 millimetre, or even 0.5 mm in particular in the case of a light source the emission light cone of the radiation of which is very small.

The handling, the positioning and the fastening of a laser source are made particularly difficult in view of the design and the shape of the light source, and in particular of the relative fragility of its connection terminals.

The invention aims to propose a solution that enables precise adjustment of the relative position of the semiconductor light source with respect to the associated optical component and that is able in particular to be implemented in the context of the mass production of light modules.

BRIEF SUMMARY OF THE INVENTION

The invention proposes a light module comprising:

at least one semiconductor light source;

an optical component that is positioned with respect to the light source;

and a reference surface on which the at least one light source and the optical component are fastened,

characterized in that the at least one light source is supported by a mount that is fastened on the reference surface.

According to other features of the light module:

it includes means for adjusting the position of the mount with respect to the reference surface and means for fastening the mount, in the adjusted position, on the reference surface;

the mount includes at least one fastening hole for the passage of an element for fastening the mount on the reference surface;

the fastening element includes a threaded rod that extends axially with radial play through the fastening hole;

the light source includes a housing that is received and positioned in a complementary recess in the mount;

the mount includes two fastening holes, and the recess is formed between the two fastening holes;

the mount includes a central body in which the recess is formed, and two opposite lateral vanes each of which extends from this body and each of which includes a fastening hole;

the housing is mounted so as to be clamped, in particular radially without play, by axial insertion into the recess in the mount;

the housing is mounted in its recess by insertion along an axis parallel to the axis of the threaded rod;

the mount includes means to be gripped by a handling element enabling the mount to be positioned with respect to the reference surface;

the light source includes connection terminals that are offset radially with respect to a central axis of its housing, and the mount includes poka-yoke means that interact with complementary means of the reference surface so as to define a preferred positioning orientation of the mount;

the light source is a laser source, and the light module includes a diffusion screen that is interposed vertically between the mount and the reference surface;

the semiconductor light source belongs to a group including in particular a laser source, at least one laser diode and at least one light-emitting diode;

the optical component belongs to a group including in particular a reflector, a collimator and a lens;

the reference surface belongs to a radiator or a heat sink.

the light source is positioned directly with respect to the mount and indirectly with respect to the optical component that is positioned with respect to the reference surface common to the mount and to the optical component.

DETAILED DESCRIPTION OF THE FIGURES

In the remainder of the description, elements having an identical structure or similar functions will be denoted by the same references.

In the remainder of the description, longitudinal, vertical and transverse orientations, indicated by the “L, V, T” trihedron in the figures, will be adopted in a non-limiting manner. A horizontal plane that extends longitudinally and transversely is also defined.

FIG. 6shows some elements and components belonging to a lighting module light module10that includes in particular a radiator12, a laser light source14and an optical reflector16.

The semiconductor light source of laser type14is in particular able to emit light radiation along a main axis of emission A.

The radiator12, illustrated inFIG. 1, is a component formed by complex shape moulding that, alongside its heat sink function, in this case performs the function of a carrier for the relative positioning and the fastening of the light source14and the optical reflector16.

In the embodiment illustrated in the figures, the radiator12has a general design symmetry with respect to a median vertical and longitudinal plane PVM indicated inFIG. 7.

The radiator12is delimited by an envelope or outer surface with respect to which the light source14and the collector16are positioned with precision, in particular so as to define a precise relative position of one component with respect to the other.

Thus, at its rear part, the radiator12includes, in order to position and fasten the optical collector16, four positioning and fastening holes18each of which is associated with a flat portion20of the outer surface of the radiator12. Each of the holes18is able to receive complementary elements20of the optical collector16.

At its front longitudinal part, the radiator12includes a portion24forming a connector plate for fastening the laser light source14by way of a mount26according to the invention.

The connector plate24is delimited by a flat upper face28, which is in this case horizontal and has a rectangular overall profile whose length extends along the transverse axis T.

The connector plate24includes, at its centre, a stepped cylindrical recess30, in this case with a circular cross section with a vertical overall axis of orientation.

The recess30is delimited vertically downwards by an annular base32.

The stepped recess30is radially open, in this case in the longitudinal direction towards the front, in the form of a vertical passage34delimited by two opposite vertical and longitudinal sides.

Symmetrically, on either side of the stepped recess30, the connector plate24includes two cavities36in the form of counterbores, each of which is delimited by a horizontal base38.

Substantially in the centre of each cavity36, the connector plate24includes a fastening pad40of frustoconical general shape that is delimited by a horizontal annular upper bearing face42, these two surfaces42being coplanar with the horizontal upper face28of the connector plate24.

Each fastening pad40includes a central orifice44that is able to receive, through screwing, a threaded rod48belonging in this case to a fastening screw50.

The light source14is in this case a laser source, which is in particular illustrated in detail inFIGS. 7, 9, 10, 11 and 13.

The laser source14includes a housing52that in this case has a cylindrical general shape with a circular cross section and that includes a lower collar54delimiting an upwardly oriented annular radial shoulder56.

The housing52is delimited by a flat lower horizontal face56in the general shape of a disc.

The laser light source14includes two connection terminals58for its supply of electric power, each of which terminals is extended by a power supply wire60.

Each connection terminal58extends vertically downwards from the lower face56.

As illustrated with precision inFIG. 13, the two connection terminals58are offset radially eccentrically with respect to the general central axis A of the housing52, which axis corresponds substantially to the main axis of emission of the light source14.

Each of the connection terminals58, when the light source14is positioned with respect to the radiator12, is offset transversely and longitudinally forwards with respect to the axis A.

According to the invention, the housing52of the laser light source14is mounted, positioned and fastened on the radiator12by way of the mount26on which the housing52of the laser source14is mounted and fastened: the mount26itself being positioned and fastened on the upper face28of the connector plate24.

The mount26is in this case in the general shape of a sheet with a horizontal orientation and with a rectangular general profile whose ends are rounded.

The mount26is delimited vertically by a flat horizontal lower face62and by a flat horizontal upper face64.

In its central part, the mount26includes a central body66formed overall with an excess thickness with respect to the upper face64.

The mount26thus takes the form of a central body66that is extended by two lateral vanes65with a transverse orientation and each of which is in the form of a sheet.

The central body66is delimited vertically downwards by a flat horizontal base68that is offset vertically upwards with respect to the plane of the lower face62.

In the vicinity of the front longitudinal edge63of the mount26, the central body66includes an indexing finger70that extends vertically downwards and that is able to be received in the passage34of the connector plate24of the radiator12so as to form a means for poka-yoking the general orientation of the mount26with respect to the connector plate24.

The central body66includes a cylindrical central recess72with a circular profile and with a vertical axial orientation orthogonal to the plane of the upper face64.

The central recess72is the recess in which the body52of the laser light source14is received and mounted.

The laser light source14, by way of its housing52, occupies a given fixed position with respect to the mount26along the three axes.

To this end, the body52may be force-fitted in the central recess72and/or fastened by adhesive bonding.

The vertical position of the housing52with respect to the mount26is defined by the radial shoulder56upwardly coming into axial abutment with the portion opposite the base68of the central body66.

When the housing52is assembled with and joined to the mount26, the method for mounting it also consists in ensuring a given angular orientation of the housing52about its axis with respect to the mount26in such a way that, as illustrated inFIG. 13, the connection terminals58are eccentric and oriented as described above, in particular longitudinally forwards facing the indexing finger70.

In the vicinity of each of its opposite transverse ends, the mount26includes a cylindrical fastening through-hole74.

Each fastening hole74is able to be passed through axially by the threaded rod48of an associated fastening screw50.

The inner diameter of each fastening hole74is markedly greater than the outer diameter of the threaded rod48, such that the latter is received in the associated hole74with radial play in order, as will be explained hereinafter, to enable adjustment of the position of the mount26with respect to the connector plate24in the horizontal plane L, T.

The lower collar54of the housing52also has radial play in the recess30in the connector plate24.

Lastly, each lateral vane65includes, between the fastening hole74and the central body66, a cylindrical through-hole76that is a grip hole for enabling the mount26to be handled with respect to the radiator12, for example by way of a motorized handling head (not shown).

Optionally, and in particular in the case of using a light source of laser type, the optical module10is equipped with a diffuser screen80, which is illustrated in detail inFIG. 14.

To mount and fasten it, the screen80includes two opposite transverse tabs82, each of which is received in an associated recess36of the connector plate24of the radiator12, each tab82being passed through by an associated pad40.

The precise positioning and the fastening of the light source14and of the optical reflector16on the radiator12is achieved as follows.

After having assembled and fastened the light source14and the mount26, the sub-assembly is brought, with respect to the radiator12, into the position illustrated inFIG. 3.

Starting from this position, the mount26, with its indexing finger70, is brought into position, with respect to the connector plate24, with its lower face62bearing horizontally flat on portions facing the horizontal upper face28of the connector plate24.

Upon this installation, the passage34receives the indexing finger70.

At this juncture, it is possible to install the desired fastening screws50partially without their threaded rod48into a fastening orifice46, without vertical clamping of the mount26.

As a variant, the fastening screws50may be installed and screwed after the step of adjusting the positioning of the mount26with respect to the connector plate24.

The handling of the mount26, for example using a manipulating robot interacting with the grip holes76, then makes it possible, as outlined inFIG. 4, to position the mount26with precision in the horizontal plane with respect to the connector plate24of the radiator12so as to position the general axis of emission of the light beam of the laser light source14with precision.

Such precise positioning is able to be ensured by any known means, for example by imaging means.

When the precise position of the mount26with respect to the connector plate24is achieved, the fastening screws50are then fully screwed so as to ensure that the mount26is immobilized on the connector plate24by vertical clamping.

At this juncture, illustrated inFIG. 5, by way of its mount26, the laser light source14is positioned with all the desired precision with respect to the radiator12.

The following step then consists in positioning and fastening the optical reflector16on the radiator12so as to precisely position and fasten the optical reflector16with respect to the laser light source14.

Thus, according to the design that has just been described, the light source14is positioned directly with respect to the mount26, which performs the function of a reference surface for the light source, and it is positioned indirectly with respect to the optical reflector16, which is itself positioned with respect to the reference surface formed by the radiator12that is the reference surface common to the mount26and to the optical reflector12.

The invention is not limited to the embodiment that has just been described.

Numerous variants are possible and able to be contemplated without departing from the scope of the invention.

The mount26may be produced for example by moulding of any material, of plastic or of metal, in particular of aluminium alloy, of Zamac, etc., its material being chosen in particular depending on deformation constraints and on thermal expansion.

The mount26may include one or more light sources, each of which is positioned with precision with respect to the mount26.

The light source14may include a non-cylindrical housing of any other shape, the mount26including a recess complementary to the shape of the housing of the light source.

The mount26may also be produced as a single component with all or some of the housing of the light source.

The mount26may also be joined to the housing of the light source by overmoulding around the latter.