The invention relates to the field of lighting systems, and in particular to lighting systems intended, for example, to be fitted to motor vehicles.
A lighting system usually comprises a light source interacting with an optical device that may, for example, comprise an optical device acting as a reflector, a mirror and/or a set of lenses for distributing the light obtained from the light source in the lighting system.
In these conditions it is useful to position the light source in a precise manner with respect to the optical references of the optical system so that the light beam is directed appropriately toward the outside of the lighting system.
This requirement for geometric precision has increased with the use of light sources formed by light-emitting diodes, and more particularly with the use of high-power laser diodes which enable the light emission to be concentrated at a precise point of very small size. These diodes are mounted on a module which acts as a heat sink and also serves as a support for the electrical connection members used to supply the diode.
Consequently there is need to provide a connecting means for coupling this module to the optical device in such a way that the light source is positioned at a predefined point in the geometric reference frame of the optical device, and that the light rays emitted by the light source are oriented at precise angles in this reference frame.
By way of example, the publication DE 10 2010 048 594 describes a coupling device of a light source installed on a module mounted on a heat sink which is coupled to an optical device acting as the optical device. The heat sink comprises a housing having reference faces against which the module is made to bear by resilient means such as springs. This device may be used to achieve the objectives described above, but requires the use of a large number of parts, and a number of springs equal to the number of reference axes, thus complicating the production and assembly of the device.
The invention therefore concerns a lighting device, notably a lighting and/or signaling device, for a vehicle, comprising a light source positioned on a module assembled onto an optical device.
This device is characterized in that the optical device and the module have first reference means, comprising:
the contact face being arranged so that, when the extension has been introduced into the slideway in a direction of introduction, the contact face bears at the contact points against the interior guide face, and the slideway and/or the extension are elastically deformed locally at the contact points. The high-power diode is mounted on the module, which may act as a heat dissipater, and the assembly is then directly assembled onto the optical device by making the extensions penetrate into the slideways. The geometric position of the module with respect to the optical device is then secured by making the reference bearing face of the module bear against the interior reference face of the slideway forming part of the optical device.
The protuberance, owing to its very small bearing face, facilitates its own deformation and that of the guide face of the slideway on which it bears, the whole operation being performed with limited force, thereby limiting the risk of breakage. The deformation of the system consisting of the protuberance and the guide face of the slideway compensates for the mechanical tolerances of the various elements, thus permitting precise adjustment, regardless of the manufacturing tolerances, of the interior reference face of the slideway against the reference face of the extension.
The protuberances, which act to some degree as mechanical catches, thus enable these reference faces to be made to bear without creating false contacts as a result of irregularities in the smoothness of the sliding face or irregularities in the shape of the extension.
The lighting system according to the invention may also have the following characteristics, separately or in combination:
The present invention also relates to a lighting device, notably a lighting and/or signaling device, for a vehicle, comprising a light source positioned on a module (3) assembled onto an optical device. The module comprises a guide opening for assembling the module onto the device and a fixing opening for fixing the module to the device, the fixing opening and the guide opening being placed in a first pair of respective positions on the module when the optical device is intended to provide a first photometric function, and the fixing opening and the guide opening being placed in a second pair of respective positions on the module when the optical device is intended to provide a second photometric function.
The lighting system according to the invention may also have the following characteristics, separately or in combination:
The invention will be more easily understood from a perusal of the attached drawings, which are provided by way of example to support the following description and are not in any way limiting, in which drawings:
The module 3 supporting the diode may also act as a heat sink and heat dissipater for discharging the heat produced by the diode. The module is preferably manufactured from a metal sheet which is cut out, pressed and bent to a desired shape.
The optical device 2 is usually made by injection of a thermosetting material or a plastic material, preferably thermoplastic, on which treatments are carried out to provide surfaces acting as mirrors 28. The slideways 21 are made in one piece with the optical device 2, and are therefore positioned in a precise manner in the reference frame of the optical device 2. An orthonormal reference frame OXYZ, corresponding to the reference frame of the optical device 2, may be used for the precise definition of the position in space of the characteristic points of this optical device, such as the position of the surface of the generally parabolically shaped mirror 28, or of the focal points, etc.
The light source placed on the module must therefore be positioned precisely in this reference frame in order to optimize the operation of the lighting system. The ideal position of the light source has been positioned in the geometric center O of the reference frame.
Each extension 31 comprises a reference bearing face 32 and a contact face 33, opposite the reference bearing face and supporting contact points P, represented here by protuberances 34 which project from the contact face 33 of the extension.
After mounting, the axes of the reference frames OXYZ and o′x′y′z′ must therefore coincide very precisely, so that the center of the diode 4 is placed very exactly at the geometric point O forming the center of the optical device 2. The axis OX here represents the general direction of introduction of the extensions 31 into the slideways 21.
The following
The cross section of the extension 31 shown in
The protuberance may have a hemispherical shape, in which case the bearing between the protuberance and the interior guide face 24 takes the form of a virtual point contact. It is also possible to form protuberances of substantially cylindrical shape, the generatrices of which lie along the direction o′y′ perpendicular to the direction of introduction o′x′, in which case the contacts between the protuberance and the interior guide face 24 of the slideway are established along a peak line forming a virtually linear contact. These shapes have the advantage of being easily produced by the pressing of the extensions 31 if the module is made from a metal sheet, but are not limiting.
To achieve the aforementioned wedge effect, provision is made for the extension 31 to have a different thickness e at each contact point P, this thickness being measured normally to the reference bearing face 32, between said contact point P and the reference bearing face 32. The thickness e1 of the extension 31 at the first contact point P1 is less than the thickness e2 of the extension at the second contact point P2.
Provision is also made for the contact points P to be included in a plane of alignment L, shown in broken lines in
The purpose of the protuberances 34 is to force the reference bearing face 32 of the extension 31 to bear on the interior reference face 22 of the slideway, without being affected by any irregularities in form of the interior sliding face 24 and the contact face 33 of the extension. The number of protuberances is therefore not limiting.
In fact, once the two reference faces 22 and 32 are in contact, any movements of the module along the axis OZ and about the axis OX and the axis OY are theoretically blocked.
An extension with only one protuberance may therefore serve this purpose. The presence of two protuberances of substantially cylindrical shape, as shown in
The aforementioned wedge effect is strengthened if the protuberance 34 slightly presses into the interior guide face 24 of the slideway. The material, preferably metal, of which the module 3 is formed is much harder than the thermoplastic material forming the optical device 2 and the slideway 21. Since the contact surface between the protuberance 34 and the interior guide face 24 is reduced, the protuberance elastically deforms the guide face locally around the contact point, thereby increasing the pressure force between the two reference faces 22 and 32.
In this case, “elastic deformation” is taken to mean that the deformation is reversible, and that the interior guide face 24 of the slideway recovers its original shape entirely when the module 3 is withdrawn from the lighting device.
It will also be noted that it is possible to make the slideway of a harder material than the module 3. In this case, it is the protuberance that undergoes the elastic deformation in order to achieve the same effects as those described above.
Thus it would be correct to speak of the elastic deformation of the system formed by the pair consisting of the protuberance and the interior guide face.
The designer of the lighting device is therefore free to choose the shape and material of the slideway 21 or of the protuberances 34 of the module in such a way that they undergo the desired elastic deformation, and to choose which of these two elements will be deformed less.
Finally, in order to achieve this effect in an optimal way, care will be taken to ensure that the number of contact points is reduced, or, in other words, that the contact surface of the protuberances with the interior guide face 24 is smaller, and preferably much smaller, than the contact surface between the interior reference face 22 of the slideway 21 and the reference bearing face 32 of the extension 3.
The number and shape of the slideways 21 is not limiting. Moreover, a single slideway could provide all the functions described above for the geometrical positioning of the module. However, the presence of two slideways, positioned symmetrically either side of the plane OXZ, makes it possible to reduce the rotation that may occur about the axis OX.
The shape of the slideways 21 may also be the subject of variants. The slideways shown in the figures have a lateral opening in the plane formed by the axes OXZ. In an equivalent manner, it would be equally feasible to form a slideway having an opening in a frontal plane perpendicular to the axis of introduction OX. The orientation of the extension 31 is then modified accordingly. Similarly, the interior reference face 22 of the slideway may be located in an equivalent manner in an upper or lower position upper along the direction OZ.
The invention also provides second reference means, for blocking the movements of the module 3 with respect to the optical device 2 along the general direction of introduction OX.
These second reference means are formed by a second reference face (23, 29) carried by the optical device 2, which is perpendicular to the axis OX, and a second reference element (35, 39) carried by the module 3 and bearing against said second reference face.
The second reference face may be supported, for example, by a wall 25 of the slideway 21 connecting the interior reference face 22 and the interior guide face 24, the interior face 23 of which wall, acting as a second reference face, is intended to bear against second reference elements 35 positioned on the front part of the extensions 31, as shown in
The projection 27 may usefully comprise a fixing opening 27a intended to interact with a fixing opening 37 formed in the positioning wall 38 of the module 3. The fixing opening 37 of the module 3 may have the general shape of a round hole. A fixing means 5, for example, but not limited to, a screw, a stop washer, or a system made of spring plate, passing through the fixing opening 37, and entering the fixing opening 27a, may then be used to fix the module 3 to the optical device 2, and to block the movement of the module 3 with respect to the optical device 2 along the axis of introduction OX.
To facilitate the introduction of the module 3 into the optical device 2, it is possible to provide a guide means 26, fitted on the optical device 2 and intended to interact with a guide opening 36 in the module. The guide opening 36 has a substantially oblong shape in the direction of the axis OZ, so as not to impede the adjustment in this direction of the interior reference face 22 of the slideway with the reference bearing face 32 of the extension 31.
The guide means 26 may have the shape of a peg of circular section (not shown) whose longitudinal direction lies along the axis OX, and which is sufficiently long in the direction of the axis OX to penetrate into the guide opening 36 during the assembly operation.
The guide means (26, 36) and fixing means (27a, 37, 5) may also act as location elements, for example if the module 3 is to be assembled onto optical devices 2 having distinct photometric lighting functions of the right/left and/or high/low beam type.
The fixing opening 37 and the guide opening 36 are then placed in a first pair of respective positions on the module 3 when the optical device 2 is intended to provide a first photometric function, such as a high beam lighting function, and the fixing opening 37 and the guide opening 36 are placed in a second pair of respective positions on the module 3 when the optical device 2 is intended to provide a second photometric function, such as a low beam lighting function.
For its part, the optical device 2 is arranged to provide a single photometric function chosen from the first and second photometric functions.
It is then possible to use substantially identical modules 3, differing only in the respective positions of the guide openings 36 and the fixing openings 37, on optical devices 2 having different photometric functions, on which devices the positions of the guide means 26 and the fixing opening 27a are adapted accordingly.
It is also possible, by way of example, to reverse the respective positions of the fixing opening 37 and the centering opening 36.
Thus, in the first pair of positions, the fixing opening 37 is positioned in a first position on the module 3 and the guide opening 36 is positioned in a second position on the module 3 when the optical device 2 is intended to provide the first photometric function. Additionally, the fixing opening 37 is positioned in said second position on the module 3 and the guide opening 36 is positioned in said first position on the module 3 when the optical device 2 is intended to provide the second photometric function.
In a complementary manner, and with the aim of pairing up a module with the appropriate optical device 2 and placing the guide means 26 and the guide opening 36 in corresponding positions, as well as the fixing opening 27a of the optical device 2 and the fixing opening 37 of the module, the fixing opening 27a and the guide means 26 of the optical device 2 are placed in the first pair of respective positions when the optical device 2 is intended to provide the first photometric function, and the fixing opening 27a and the guide means 26 of the optical device 2 are placed in the second pair of respective positions when the optical device 2 is intended to provide the second photometric function.
The embodiment of the location element as detailed above is not limiting, and may be the subject of numerous variants in which guide means and fixing means are placed in clearly defined locations to permit the assembly of standard elements, in this case modules for supporting a diode, which are slightly modified according to their intended use, onto members providing different functions, in this case optical devices providing distinct photometric functions.
Finally, the lighting system according to the invention may comprise third reference means for blocking the movement of the module with respect to the optical device along the axis OY.
These third reference means may usefully be positioned on the guide means 26 carried by the optical device 2. The guide means comprise, as shown in
In a variant embodiment, for a more precise positioning of the light source, the third reference means may be formed by a third slideway. In this case, the optical device comprises three slideways 21, each oriented along the axis OX, of which two are coplanar and the third slideway is located in a plane substantially perpendicular to the first two slideways. The module then comprises a third extension 31 intended to interact with the third slideway 21. In this last-mentioned configuration, it is necessary to slightly enlarge the fixing opening 37 and the guide opening 36 in the direction OY, so as to leave a clearance for the adjustment of the position of the module 3 in the direction OY.
The assembly of the module 3 onto the optical device 2 is carried out in an extremely simple way, by introducing the guide means 26, in the direction OX, into the guide opening 36, so as to cause the extensions 31 to enter the slideways 21. This introduction movement is interrupted when the second reference element 35 or 39 respectively comes to bear against the second reference face 23 or 29 respectively. The screw 5 may be used to lock the assembly in the two directions of the axis OX.
The module 3 supporting the light source 4 may be mounted and removed easily, thus facilitating any work that may need to be done on the lighting system in the course of the maintenance of the vehicle.
The light source 4 is then perfectly positioned in the center O of the optical device 2, and any movement of the module 3 along or about the axes OX, OY and OZ is prevented.
The embodiments of the invention described above are not limiting, and those skilled in the art will be able to derive teachings from the above instructions to achieve the desired objects using equivalent forms and arrangements.
Number | Date | Country | Kind |
---|---|---|---|
14 59306 | Sep 2014 | FR | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2015/072073 | 9/25/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2016/050625 | 4/7/2016 | WO | A |
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7665872 | Nakabayashi | Feb 2010 | B2 |
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Number | Date | Country |
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2 317 213 | May 2011 | EP |
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Entry |
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International Search Report dated Jan. 12, 2016 in PCT/EP2015/072073 filed Sep. 25, 2015. |
French Search Report dated May 22, 2015 in FR 1459306 filed Sep. 30, 2014. |
Number | Date | Country | |
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20170211768 A1 | Jul 2017 | US |