Integral mounting for luminous device with micro-mirror array

Abstract

The invention relates to a support (4) for a light module (2), particularly for a motor vehicle, comprising a receiving area for at least one light source (16); a receiving area for an optical device for shaping the light emitted by the light source(s) (16); a receiving area for a microelectromechanical system with at least one mirror adapted to receive the rays from the optical shaping device; and a receiving area for at least one optical projection device (22) receiving the rays reflected by the mirror(s) of the microelectromechanical system (8). The support (4) forms a cavity (30) with an opening and comprises an outer surface around said opening, said surface forming the receiving area of ​​the microelectromechanical system.

Description

[0001] The invention relates to the field of lighting and light signaling, in particular for motor vehicles. More particularly, the invention relates to a light signaling device capable of producing light pictograms by means of a microelectromechanical system with a matrix of micro-mirrors.

[0002] Published patent document US 2015 / 0175054 A1 discloses a lighting device for a motor vehicle headlight. The device comprises a laser-type light source, a microelectromechanical system serving as a deflector for the laser light, a phosphor-type luminophore element capable of converting the monochromatic light reflected by the deflector, and an optical device comprising several lenses receiving the white light coming from the luminophore element. The deflector can be controlled so as to modulate the light image thus produced. The device comprises a support for supporting these different elements. The support is made up of several parts assembled together, directly or indirectly, for example via the housing of the device or the headlight. However, such an assembly has the consequence of forming chains of tolerances reducing the relative positioning accuracy of the different elements.In some optical configurations, especially when the light source is very close to the deflector, tight tolerances are required to achieve a satisfactory result. Furthermore, in this teaching, the deflector is arranged on the inner face of a wall of the support, whereas this type of component is usually fixed on a board with printed circuit, such a board being potentially bulky, especially when many electronic components are necessary for the control of the deflector.

[0003] Furthermore, documents US 2006 / 078266 A1 and JP 2016 091976 A describe known devices comprising a matrix of micro-mirrors.

[0004] The invention aims to overcome at least one of the drawbacks of the aforementioned state of the art. More particularly, the invention aims to propose a solution ensuring precise positioning of the optical components of a light device comprising a microelectromechanical system provided with one or more mirrors.

[0005] The invention relates to a light device according to claim 1.

[0006] According to the invention, the support comprises a single-piece body, preferably made of aluminum, said body forming the reception areas for the light source(s), the optical shaping device and the optical projection device.

[0007] According to the invention, the support comprises a plate capable of being fixed to the body in order to partially close the cavity and comprising the outer surface forming the reception area of ​​the microsystem.

[0008] According to an advantageous embodiment of the invention, the cavity is covered with an anti-reflective and / or absorbent coating, preferably black.

[0009] According to an advantageous embodiment of the invention, the cavity is delimited by the reception zone of the optical shaping device and the reception zone of the optical projection device.

[0010] According to an advantageous embodiment of the invention, at least one, preferably each, of the reception zones of the optical devices comprises an orifice made in the support and a shoulder around said orifice.

[0011] According to an advantageous embodiment of the invention, the device comprises within the cavity a cantilevered tongue with an orifice intended to be crossed by the light reflected by the microsystem towards the optical projection device.

[0012] According to an advantageous embodiment of the invention, the light source(s), the optical shaping device and the microsystem form a first optical axis, and said microsystem and the optical projection device form a second optical axis, the angle between said optical axes being between 40° and 65°, preferably between 45° and 60°.

[0013] According to an advantageous embodiment of the invention, the light source(s) are of the light-emitting diode type on a plate arranged on a radiator fixed to the receiving area of ​​said light source(s). According to another advantageous embodiment of the invention, alternative to the above embodiment, the light source(s), of the light-emitting diode type, are arranged via a base directly on the radiator fixed to the receiving area of ​​said light source(s).

[0014] According to an advantageous embodiment of the invention, the optical shaping device comprises a biconvex lens and / or the projection device comprises a biconvex lens and a biconcave lens.

[0015] According to an advantageous embodiment of the invention, the or each of the lenses of the optical device(s) is held in place by a flange, fixed for example by screwing, gluing, welding, crimping, riveting, by means of dowels or rivets, or any other fixing means, or by the combination of two or more of these means.

[0016] According to an advantageous embodiment of the invention, the optical shaping device has a diameter greater than twice, preferably three times, that of the optical projection device.

[0017] According to an advantageous embodiment of the invention, the microsystem is on a printed circuit board, said board being fixed to the support so as to press said microsystem against the receiving area of ​​said microsystem.

[0018] According to an advantageous embodiment of the invention, the light device is a rear signaling light capable of forming pictograms in the light beam produced, said pictograms being a function of programming of the microsystem.

[0019] The measures of the invention are interesting in that they make it possible to ensure exact positioning of the various components, including the microelectromechanical system while it is on a printed circuit board.

[0020] Other features and advantages of the present invention will be better understood with the aid of the description and the drawings among which There figure 1 is a perspective representation of a light device according to the invention; The figure 2 is a perspective representation of the optical components of the light device of the figure 1 ; There figure 3 is a view from below of the support of the light device of the figure 1 ; There figure 4 corresponds to the figure 3 where the partial closing plate of the support cavity is absent; The figure 5 is a median longitudinal sectional view of the light device of the figure 1 .

[0021] THE figures 1 à 5 illustrate one embodiment of the invention, it being understood that other embodiments are conceivable.

[0022] There figure 1 is a perspective representation of a light device 2 according to the invention. The light device 2 is in this case a light signaling device for a motor vehicle. It essentially comprises a support 4, optical components arranged on the support 4 and a printed circuit board 6 with electronic components and an electromechanical optical microsystem 8. The latter comprises a matrix of micro-mirrors capable of being individually pivotally controlled. Such a microsystem is commonly called a micro-mirror matrix or DMD (acronym for “Digital Micromirror Device”). Each mirror can take two positions: it can tilt by 10 to 15° along the same axis so as to reflect the light either towards a diffusion lens or towards an absorbing surface. It is said that it switches “ on » or « off », this regime is therefore binary. Such a microsystem is in itself well known to those skilled in the art.

[0023] The support 4 of the light device 2 comprises a body 10 on which a radiator 12 is mounted. The latter comprises an extended portion 12.1 receiving a plate 14 with one or more light sources 16, for example of the light-emitting diode type. The radiator 12 also comprises fins 12.2 extending essentially parallel to each other from the extended portion 12.1. The body 10 comprises a receiving zone 10.1 of the radiator 12 supporting the light source 16. The body forms a recess 18 opposite the light source 16. The bottom of this recess 18 forms a receiving zone 10.2 of a shaping lens 20. The latter forms an optical device for shaping the light emitted by the light source 16. The body 10 forms a cavity (not visible in the figure 1 ) with an opening on the lower face 10.3 of said body. The microelectromechanical system 8 is arranged opposite this opening in order to receive the light beam formed by the shaping lens 20. The body 10 also comprises a receiving zone 10.4 of an optical projection device 22. The latter may comprise two lenses, only one of which is visible at the figure 1 .

[0024] The body 10 is advantageously made of a single piece, for example made of aluminum. The same applies to the radiator 12. Each of these two elements can be produced by machining or molding followed possibly by machining operations.

[0025] There figure 2 illustrates the optical components of the light device 2 of the figure 1 . These can be seen to include a diaphragm 24 formed by a tab 24.1 provided with an orifice 24.2. The latter is arranged between the microelectromechanical system 8 and the optical projection device 22. The role of the diaphragm is to cut off the light rays which propagate too far from the nominal position in order to ensure good definition, i.e. good sharpness, of the image created by the system. The optical projection device 22 comprises a first lens 22.1 of the converging type and a second lens 22.2 of the diverging type. The second lens has a significant thickness to the point of having a generally cylindrical shape. The lens 20 for shaping the beam of light emitted by the light source 16 is a biconvex converging lens, configured to form a beam converging towards the optical microsystem and illuminating the optical surface of said system.It can be observed that the light source 16, the shaping lens 20 and the microsystem 8 are aligned along a first optical axis 26.1 and that said microsystem 8, the diaphragm 24 and the optical projection device 22 are aligned along a second optical axis 26.2. The angle α formed by these two optical axes is advantageously between 40° and 70°, preferably between 50° and 70°, or between 40° and 65°, or between 45° and 60°.

[0026] THE figures 3 et 4 illustrate the light device of the figure 1 , without the plate and the microelectromechanical system, seen from the underside of the support.

[0027] To the figure 3 , it can be observed that the support 4 further comprises an element 28, for partially closing the cavity 30, within the body 10. This element 28 is formed by a plate 28.1 provided, at a peripheral portion, with means for fixing to the body 10, such as in particular orifices intended to receive fixing screws. The plate 28.1 is also provided, at a central portion, with an opening 28.2. This is intended to allow the light coming from the shaping lens 20 to encounter the optical part of the microelectromechanical system arranged opposite the opening 28.2 in question. The element 28 may for this purpose comprise pads 28.3 forming bearing surfaces of the microelectromechanical system. These pads 28.3, advantageously three in number in order to be isostatic, form surfaces similar to point surfaces.The microelectromechanical system fixed to the printed circuit board can then be fixed to the support so that the microelectromechanical system is under pressure on the pads 28.3, thus ensuring contact and, therefore, exact positioning in the direction perpendicular to the face 10.3 of the body 10. Means for positioning the board, in the plane of said board, can be provided, such as in particular pins passing through orifices in the board and in the body 10 at the level of the face 10.3.

[0028] Always at the figure 3 as well as to the figure 4 , the diaphragm 24 can be observed in the cavity 30 as well as its method of fixing. The tab 24.1 forming the diaphragm comprises at its end opposite the orifice 24.2 two orifices 24.3 cooperating with positioning rods embedded in the body. It also comprises a fixing orifice 24.4 central relative to the positioning orifices 24.3, said orifice receiving a fixing screw engaging with the body 10. For this purpose, the body 10 comprises in the cavity 30 a recess forming a bearing surface for the tab 24.1, allowing the latter to pass under the element 28 (according to the point of view of the figure 3 ). It is interesting to note that the orifice 24.2 is located at the end of the tab 24.1 which is located on the side of the shaping lens 20, so as to avoid any obstruction of the light beam propagating from the shaping lens 20 towards the microelectromechanical system. The proximity between this beam and the edge of the tab 24.1 at the orifice 24.2 is visible at the figure 2 .

[0029] There figure 4 corresponds to the figure 3 , where however the element 28 is absent. It can be seen that the first lens 22.1 of the optical projection device 22 is held in place on the body 10 by means of a first flange 32. This may have an open profile, in this case U-shaped, with the opening directed towards the shaping lens 20. The shaping lens 20 and the first lens 22.1 are in fact very close to each other to the point that no space is available for a portion of flange between the two lenses. The first flange 32 is advantageously fixed to the body 10 by screws engaging in threaded holes made in said body.

[0030] There figure 5 is a sectional view of the light device of the figure 1 , the section being along a median longitudinal plane, that is to say along a plane generally parallel to the plane of the figure 1 and passing through the center of the device. The device in section at the figure 5 is shown without the printed circuit board and without the microelectromechanical system.

[0031] The two optical axes 26.1 and 26.2 can be seen, as well as the lens assembly. In fact, the shaping lens 20 comprises two fixing ears 20.1 and 20.2 ( figure 2), these two ears being advantageously diametrically opposed. They are housed in cavities formed in the body 10, so as to ensure an angular orientation of the shaping lens 20, the latter not being able to be symmetrical in revolution. A second flange 34, in this case circular and closed, is arranged on the peripheral edge of the shaping lens 20, including the ears, and is fixed to the body by means of screws. Similarly, the second lens 22.2 of the optical projection device is held in place by a third flange 36, also arranged on the peripheral edge of the second lens 22.2 and is fixed to the body by means of screws.

[0032] The shaping lens 20 and the second lens 22.2 are placed from outside the body by insertion into the respective receiving areas. The first lens 22.1 is, for its part, placed via the cavity 30.

Claims

1. Luminous device (2), notably for a motor vehicle, comprising: - a support (4); - a heat sink (12) supporting at least one light source (16) disposed on the support (4): - an optical device (20) for forming the light emitted by the light source or sources (16), said device being disposed on the support (4); - an electromechanical microsystem (8) with at least one mirror capable of receiving the rays originating from the optical forming device, said microsystem being disposed on the support (4); and - an optical projection device (22) capable of receiving the light reflected by the mirror or mirrors of the electromechanical microsystem (8), said device being disposed on the support (4); said support (4) comprising a reception zone for the electromechanical microsystem (8) said support (4) comprising a body (10) comprising: - a reception zone (10.1) for the heat sink (12) supporting at least one light source (16); - a reception zone (10.2) for the optical device for forming the light emitted by the light source or sources (16); and - a reception zone (10.4) for the optical projection device (22) receiving the rays reflected by the mirror or mirrors of the electromechanical microsystem (8); characterized in that the body (10) is made of single piece, preferentially of aluminum; in that the body (10) forms a cavity (30) with an aperture; and in that the support (4) comprises an element (28) formed by a plate (28.1) that can be fixed to the body (10) in order to partially seal the cavity (30), the plate (28.1) being provided, a central portion, with an opening (28.2) intended to allow light from the optical device (20) for forming the light to reach the optical part of the electromechanical microsystem (8) which is positioned in front of the said opening (28.2) the plate (28.1) comprising an outer surface around said opening (28.2), said outer surface forming the receiving area for the microsystem (8).

2. Luminous device (2) according to claim 1, characterized in that the cavity (30) is covered with antireflection and / or absorbent coating, preferentially black.

3. Luminous device (2) according to one of Claims 1 to 2, characterized in that the cavity (30) is delimited by the reception zone (10.2) for the optical forming device and the reception zone (10.4) for the optical projection device (22).

4. Luminous device (2) according to one of Claims 1 to 3, characterized in that at least one, preferentially each, of the reception zones (10.2, 10.4) for the optical forming device and the optical projection device (22) comprises an orifice formed in the support (4) and a shoulder around said orifice.

5. Luminous device (2) according to one of Claims 1 to 4, characterized in that it comprises, within the cavity (30), a tongue (24.1) overhanging and with an orifice (24.2) intended to be passed through by the light reflected by the electromechanical microsystem (8) toward the optical projection device (22).

6. Luminous device (2) according to any of one of preceding claims, characterized in that the light source or sources (16), the optical forming device and the microsystem (8) form a first optical axis (26.1), and said microsystem and the optical projection device (22) form a second optical axis (26.2), the angle between said optical axes lying between 40° and 65°, preferentially between 45° and 60°.

7. Luminous device (2) according to any of one of preceding claims, characterized in that the light source or sources (16) are of the light-emitting diode type on a board (14) disposed on a heat sink (12) fixed to the reception zone (101) for said light source or sources (16).

8. Luminous device (2) according to any of one of preceding claims, characterized in that the optical forming device comprises a forming lens (20) which is biconvex and / or the projection device (22) comprises a first lens (22.1) which is biconvex and a second lens (22.2) which is biconcave.

9. Luminous device (2) according to Claim 8, characterized in that the or each of the lenses (20, 22.1, 22.2) of one or all of the optical forming device or the optical projection device (22) is held in place by a flange (32, 34, 36).

10. Luminous device (2) according to any of one of preceding claims, characterized in that the optical forming device has a diameter greater than two times, preferentially three times, that of the optical projection device (22).

11. Luminous device (2) according to any of one of preceding claims, characterized in that the electromechanical microsystem (8) is on a printed circuit board (6), said board being fixed to the support (4) so as to press said microsystem against the reception zone for said microsystem.

12. Luminous device (2) according to any of one of preceding claims, characterized in that it is a rear signaling light capable of forming pictograms in the light beam produced, said pictograms being a function of a programming of the microsystem.

13. Luminous device (2) according to any of one of preceding claims, in which the element (28) comprises blocks (28.3) forming bearing surfaces for the electromechanical microsystem (8).

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