EP2302292A1 - Optical module with folder formed by a transparent material/air dioptre - Google Patents
Optical module with folder formed by a transparent material/air dioptre Download PDFInfo
- Publication number
- EP2302292A1 EP2302292A1 EP10177944A EP10177944A EP2302292A1 EP 2302292 A1 EP2302292 A1 EP 2302292A1 EP 10177944 A EP10177944 A EP 10177944A EP 10177944 A EP10177944 A EP 10177944A EP 2302292 A1 EP2302292 A1 EP 2302292A1
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- EP
- European Patent Office
- Prior art keywords
- reflector
- focus
- module according
- optical module
- blade
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/60—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution
- F21S41/65—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution by acting on light sources
- F21S41/663—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution by acting on light sources by switching light sources
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
- F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
- F21S41/162—Incandescent light sources, e.g. filament or halogen lamps
- F21S41/164—Incandescent light sources, e.g. filament or halogen lamps having two or more filaments
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/20—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by refractors, transparent cover plates, light guides or filters
- F21S41/25—Projection lenses
- F21S41/255—Lenses with a front view of circular or truncated circular outline
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/30—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by reflectors
- F21S41/32—Optical layout thereof
- F21S41/321—Optical layout thereof the reflector being a surface of revolution or a planar surface, e.g. truncated
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/30—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by reflectors
- F21S41/32—Optical layout thereof
- F21S41/322—Optical layout thereof the reflector using total internal reflection
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/30—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by reflectors
- F21S41/32—Optical layout thereof
- F21S41/33—Multi-surface reflectors, e.g. reflectors with facets or reflectors with portions of different curvature
- F21S41/331—Multi-surface reflectors, e.g. reflectors with facets or reflectors with portions of different curvature the reflector consisting of complete annular areas
- F21S41/333—Multi-surface reflectors, e.g. reflectors with facets or reflectors with portions of different curvature the reflector consisting of complete annular areas with discontinuity at the junction between adjacent areas
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/30—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by reflectors
- F21S41/32—Optical layout thereof
- F21S41/36—Combinations of two or more separate reflectors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/40—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by screens, non-reflecting members, light-shielding members or fixed shades
- F21S41/43—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by screens, non-reflecting members, light-shielding members or fixed shades characterised by the shape thereof
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
- F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
- F21S41/141—Light emitting diodes [LED]
- F21S41/147—Light emitting diodes [LED] the main emission direction of the LED being angled to the optical axis of the illuminating device
- F21S41/148—Light emitting diodes [LED] the main emission direction of the LED being angled to the optical axis of the illuminating device the main emission direction of the LED being perpendicular to the optical axis
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
- F21S41/30—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by reflectors
- F21S41/32—Optical layout thereof
- F21S41/36—Combinations of two or more separate reflectors
- F21S41/365—Combinations of two or more separate reflectors successively reflecting the light
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- F21Y2115/00—Light-generating elements of semiconductor light sources
- F21Y2115/10—Light-emitting diodes [LED]
Definitions
- the invention relates to an optical lighting module for an automotive projector.
- the optical module typically comprises a light source, a reflector and a lens, the rays emitted by the light source from the first focus of the reflector are reflected substantially toward the second focus of the reflector.
- the invention also relates to a projector preferably for motor vehicles and comprising such a module.
- Lighting modules equipped with one or more light-emitting diode-type light sources typically include a light source, an ellipsoidal section reflector, and a lens. Such modules are known, for example, from the patent document US 4,914,747 .
- the light-emitting diode light source can be likened to a quasi-point source and is disposed at the first focus of the reflector.
- the rays emitted by the light source are mostly reflected towards the second focus of the reflector.
- a generally planar reflective surface is disposed near the second focus to reflect upwardly the lens rays reflected by the reflector and passing near and behind the second focus, ie between the second focus and the second focus. focus and reflector.
- the so-called folding reflective surface has the effect of cutting and folding the image of the light source according to a profile that corresponds to its front edge said cutting edge. A cutoff of the projected beam is necessary and required from a legislative point of view for common functions such as "code” and "fog" functions for example.
- the cut can be provided by a cover which is formed of a vertical plate of suitable profile and which is interposed axially between the elliptical reflector and the convergent lens, near the second focus of the reflector.
- the cache makes it possible to mask the light rays coming from the light source and reflected by the reflector towards the lower part of the focal plane of the convergent lens, and which, in the absence of the cover, would be emitted by the projector above the cut.
- a major disadvantage of the cache is that a large part of the light energy emitted by the source is dissipated in the rear face of the cache.
- an optical module as described above and able to perform the dual function "code” and "route” is described in the patent document mentioned above. It comprises two half-plane reflectors arranged in opposite manner and having their second homes in common.
- the folder is a flat element covered with a strip of material reflecting on one of its two faces or on both sides, at the level of the cutting edge. It thus has a non-zero thickness which has the effect of generating a loss of lighting power at the cut-off in "road” function.
- the folder is constituted by the application of a reflective coating on the upper edge of a block of transparent material.
- the latter is arranged so that its upper edge is generally plane and aligned with the optical axis of the reflector, near the second focus.
- This embodiment of the folder is interesting insofar as the thickness of the folder is extremely thin, typically of the order of one micron. This fineness of the folder, especially at the cutoff edge, that is to say at the front edge at the second focus, minimizes the loss of lighting power at the cutoff.
- This embodiment of the folder has a major disadvantage, namely that the layer being deposited by a vacuum deposition technique, it is difficult to accurately limit the deposit to the edge of the transparent block, any exceeding the deposit on one of the the faces of the block, in particular the front face, resulting in inaccuracies in the cut and irregularities of lighting power in the beam at the cut in "road" mode.
- the folder is made by applying a reflective layer on the upper face of a block of transparent material, similar to the teaching of the previously discussed document.
- the block here has a spherical bottom surface so as not to deflect the rays from the lower reflector. Due to the vacuum deposition technique of the reflective layer, the construction of the folder of this document has the same disadvantages as the previously discussed document.
- the invention aims to provide a lighting module that overcomes at least one of the aforementioned problems. More particularly, it aims to provide a lighting module with a folder whose cut is precise and easy to achieve, more particularly a folder of very small thickness or almost zero.
- the invention consists of an optical module for a motor vehicle lighting device, comprising: a reflector with a first focus for a light source, a second focus and an optical axis passing through the first and second focus of said reflector; a dioptric element of the convergent lens type arranged on the optical axis of the reflector so as to receive the light rays of said light source from an area corresponding to the second focus of said reflector and to emit a light beam; a so-called bending surface disposed near the second focus of said reflector, said bender being adapted to reflect a portion of the rays reflected by the reflector towards a portion of the dioptric element; wherein said folder is formed by a diopter capable of subjecting to total reflection the rays reflected by the reflector meeting it.
- the embodiment of a dioptre as a folder is a simplification of realization compared to known reflecting surfaces.
- the converging lens has a focal point positioned about the second focus of the reflector, so that the arrangement of the reflector and the lens is such that a ray passing through the second focus of the reflector emerges from the lens parallel to the reflector. optical axis of the optical module.
- the diopter is generally plane and is generally aligned with the optical axis of the reflector.
- the diopter is formed by the surface separating a solid transparent medium and a medium consisting of air.
- the module comprises two diopters formed by an air layer between two transparent materials. This construction makes it possible to provide two-sided reflection.
- the module comprises a first blade of transparent material arranged to have a generally flat wafer and generally aligned with the optical axis of the reflector, the surface separating the transparent material and the air forming the diopter.
- the module comprises a second blade of transparent material with a wafer superimposed on the edge of the first blade so as to form an air layer between said first and second blades, the separating surface the transparent material of said second blade and the air forming a second diopter. Since the air layer can be extremely thin, the double-sided folder resulting from these two dioptres can be of a very thin thickness, or even zero at the cutting edge, which greatly improves the homogeneity of the power of lighting at the cut-off in "road" lighting mode.
- the air layer is formed by a draft angle of at least one of the first and second blades.
- the air layer is wedge-shaped whose tip is disposed at the second focus of the reflector. This construction of the air layer ensures a zero thickness of the folder at the cutoff edge, which is an improvement of the photometric image at the cutoff edge in "road" lighting mode.
- the air layer is formed by non-flatness of the wafer of at least one of the first and second blades.
- This alternative construction of the air layer is also very interesting because it can confer a very thin and constant thickness to the folder while being quite simple to implement.
- the reflector is a first concave reflector, for example in the form of a half-shell
- the module comprises a second concave reflector, for example in the form of a half shell opposite said first reflector, said second reflector having a first focus for a light source, a second focus coinciding with the second focus of said first reflector and an optical axis passing through said first and said second focus.
- each concave reflector is delimited in the direction of the other reflector by a plane passing through the first and the second focus.
- the or at least one of the diopters is approximately in the plane passing through the first and second foci of the corresponding reflector and delimiting said reflector.
- the corresponding reflector means the reflector reflecting the light which will then be partially reflected by the diopter.
- the diopter or diopters are approximately parallel and in said plane.
- the diopters are in the respective and corresponding planes.
- the second blade comprises a surface facing the second reflector curved so as to have a greater angle of incidence relative to a plane perpendicular to the optical axis of said second reflector. This measure makes it possible to recover certain rays that would otherwise be lost. It increases the lighting efficiency of the module.
- the surface of the second blade, directed towards the second reflector has a curved profile approaching said reflector as one moves away from its optical axis.
- At least one of the first and second blades has a generally circular outer profile corresponding approximately to the outer profile of the corresponding reflector.
- the invention also consists of a motor vehicle headlight comprising a module as described above.
- Embodiments of the invention are illustrated in the figures and described hereinafter with respect to a mounting position of the device in a vehicle as a projector.
- This type of application although preponderant is not limiting.
- Terms used such as “horizontal”, “vertical”, “high”, “low”, “upper”, “lower”, “forward” and “backward”, for example, describing the positions of different elements are not to be interpreted in an absolute but relative manner, thus describing the positions of the elements with respect to their arrangement in the figures.
- the described lighting devices could be mounted in other positions and / or for other applications.
- the relative positions of the various optical elements such as light sources, reflectors and lenses expressed for simplicity of understanding by alignment of the optical axes and / or correspondence of the respective foci are not to be interpreted accurately in the measurement where slight variations are possible or even desirable in order, inter alia, to correct the non-perfect character and some optical aberrations of the optical elements or to obtain some additional effects.
- a lighting module according to the invention is illustrated in section at the figure 1 .
- This is a schematic representation illustrating the optical principle of operation of the module.
- the module comprises a first ellipsoidal reflector in the form of a half-shell 2 with a first and a second focus, a first light source 4 disposed at the first focus of the reflector 2, a second ellipsoidal reflector in the form of a half-shell 12 with a first and a second focus, a second light source 14 disposed at the first focus of the reflector 12, and a converging lens 10.
- the two reflectors 2 and 12 are arranged so that their optical axes passing through the first and second focus, respectively, are confused and constitute the optical axis 8 of the lighting module.
- the plane defining the first reflector may comprise, as illustrated here, the optical axis of said first reflector.
- the plane delimiting the second reflector may comprise, as also illustrated here, the optical axis of said second reflector. In the case illustrated in figure 1 these planes are merged and form the plane of separation of the two reflectors.
- the reflectors are also arranged so that their second foci 6 are merged and correspond to the focal point of the convergent lens 10.
- a first blade of transparent material 16 is disposed opposite the upper reflector 2, transversely to the optical axis 8 so as to have a generally flat lower edge and in the plane of separation of the two reflectors.
- a second blade of transparent material 18 is disposed facing the lower reflector 12, also transversely to the optical axis 8 so as to have a generally flat upper edge and in the plane of separation of the two reflectors.
- the upper blade 16 is of substantially constant thickness and is preferably perpendicular to the optical axis 8.
- the lower blade 18 has a variable thickness, namely that the front face is substantially perpendicular to the optical axis and the rear face has a profile approaching the lower reflector 12 as one moves away from the optical axis 8.
- the thickness of the lower blade 18 is variable.
- the thicknesses of the upper and lower blades are essentially identical and the front surfaces of the two blades are aligned with the focus 6.
- the apparent contact area of the two blades 16 and 18 is illustrated in the enlarged view of this area. It is observed that the edge of each of the two blades has a draft angle so as to form a wedge of air whose tip is directed forward and corresponds to the focus 6.
- the draft angle is typically of the order of 1 °, typically in a range from 0.5 ° to 3 °, preferably from 0.5 ° to 2 °, more preferably from 0.5 ° to 1.5 °.
- the separation planes of the first and second reflectors are not confused and form a relative angle of inclination, one can choose a larger draft angle, so that the draft angle corresponds to this angle of inclination .
- the wedge of air thus formed constitutes a very thin layer of a medium whose refractive index is substantially different from that of the solid transparent materials of the upper blades 16 and lower 18.
- This thin layer of air thus constitutes with each of the blades 16 and 18 a diopter.
- a diopter is a surface separating two transparent media of different refractive indices. If the light propagates in a straight line in a homogeneous and isotropic medium, it is deflected during the passage of a diopter: there is refraction. Each of these two diopters is capable of subjecting the light rays meeting it with an angle of incidence greater than a given value to a reflection and thus to play the role of a reflective surface.
- the phenomenon of total reflection occurs when a light ray arrives on the separation surface of two media of different optical indices with an angle of incidence greater than a critical value. There is no transmitted refracted ray and only a reflected ray remains. This phenomenon only occurs when the incident light ray is in a medium of greater index than the refracted ray. This is the case here because the material of the blade 16 or 18, typically glass or plastic material such as polycarbonate has a refractive index substantially greater than the air.
- ⁇ arcsin not 2 not 1 where n 2 is the refractive index of the medium formed by the air layer and n 1 is the refractive index of the material of the blade, and ⁇ the angle of incidence of the radius with respect to the perpendicular of the surface forming the diopter.
- the refractive index of the material of the blades is of the order of 1.5 and the index of refraction of the air is of the order of 1, it follows that the refractive limit angle is order of 41 °. This means that light rays incident on the diopters with an angle greater than about 41 ° will be subject to total reflection, like a reflective surface.
- the total reflection provided by the diopter has virtually no loss in contrast to a conventional reflecting surface which generally has a reflection loss of the order of 15%.
- Various transparent plastics materials are possible for the blades, such as for example polymethyl methacrylate (often abbreviated to PMMA) or polycarbonate. Glass can also be used as an alternative to transparent plastics.
- the thickness of the blade is of the order of a few millimeters, typically from 2 to 15 mm, preferably from 3 to 10 mm, more preferably from 4 to 8 mm.
- the light source 4 of the upper reflector 2 although assimilable to a quasi-point source emits slightly off-center rays with respect to the main rays emitted by the center of the source.
- a so-called main ray 20 emitted by the source 4 is illustrated in FIG. figure 1 .
- This main beam meets the reflective inner surface of the ellipsoidal section reflector and is then reflected towards the upper blade 16. It is refracted a first time when it meets the rear surface of the blade 16 by the change of index of refraction (air / transparent material of the blade) and goes to the focus 6 at the front surface of the blade. On leaving the blade 16 at the focus 6, the spoke is refracted a second time to then meet the lens 10 in its lower half.
- a first secondary ray 22 emitted by the source 4 is also illustrated. It meets the reflective surface of the reflector and is reflected. For the purposes of description, the rays that will pass through the second focus 6, will be considered as main rays. The rays which will pass over the second focus 6, will be considered as secondary rays. In figure 1 , we have chosen a secondary ray 22 which meets the reflector at the same point as one of the main rays, such as the main ray 20, but with a larger angle of incidence. It follows that it is reflected with a correspondingly larger angle directed towards the front of the focus 6.
- the spoke 22 is deflected a first time to the re-entry into the material of the blade and a second time to its exit, au- above the second focus 6 and therefore the focal point of the lens, and then to the lower half of the lens 10.
- a second secondary ray 24 emitted by the source 4 is also shown in FIG. figure 1 . It meets the reflective surface of the reflector at the meeting point of the main ray with a lower angle of incidence and is reflected with a corresponding lower angle. It is directed so as to meet the optical axis at the back of the focus 6.
- the diopter formed the blade 16 and the air layer constitutes a folder 17 which has the effect of "folding" the rays such as the radius 24 which otherwise would meet the lens in the lower part at a point and with an angle of incidence as they would be refracted at the exit of the lens directed upwards and would form the top of the projection image.
- the folder thus provides a cutoff function of the beam projected by the lens.
- the main and secondary rays meet and cross the lens.
- the main rays, such as the main beam 20 illustrated, pass through the focal point of the lens and therefore leave it from being parallel to the optical axis 8.
- the secondary rays such as the first 22 and second 24 illustrated secondary ray
- they pass over the focus of the lens, they come out of the lens being inclined downward and thus form the bottom of the image projected by the module below the cut.
- the cut in the beam will be sharp and will have the shape of the edge of the blade 16, the latter being positioned at the focus of the lens.
- the lighting function "code”, that is to say with cutoff, is provided by the upper reflector 2 and its light source 4, thus producing a beam corresponding to the photometric image of the figure 5 .
- the cutting edge corresponds to the shape of the edge of the blade 16, for example to the line of contact of the two blades 16 and 18 at the focus. This line of contact typically has a profile with a projection (not visible in the figures) at the central level so as to ensure a slightly higher cut on one side than the other, in accordance with the requirements of the legislation.
- the "road" lighting function is provided by energizing the upper and lower light sources 14.
- the rays emitted by the lower light source 14 are in addition to those emitted by the upper source. has been described for the upper reflector, the same phenomena occur for the rays emitted by the lower light source 14 and reflected by the reflector 12, with the difference that there is inversion between the two upper and lower halves of the lens . This has the consequence that the rays reflected by the lower reflector 12 which cross the optical axis in front of the focus and below the focus of the lens out of the upper half of the lens 10 being inclined upwards, which is the additional lighting in the upper half of the projected image, as shown in figure 6 .
- these rays are deflected a first time when they enter the blade 18 and then a second time when they leave it to go to the upper half of the lens.
- the rays that meet the lower diopter formed by the blade 18 and the air layer, such as the radius 26 illustrated in FIG. figure 1 are also refracted a first time when they enter the blade 18 to be then subjected to total reflection for the same reasons as those developed in relation to the rays of the upper source.
- the reflected rays are then refracted a second time as they exit the blade 18 and then move to the lower half of the lens.
- the folder 17 thus makes it possible to exploit these rays for the upper part of the image of the beam by "folding" them towards the lower half of the lens and exploiting the inversion of the phenomena.
- the very small thickness of the folder in practice of the order of a tenth of a millimeter to its maximum thickness in the case of the air wedge as described above (of the order 0.14 mm for a 4 mm thick blade or on the order of 0.28 mm for a 8 mm thick blade), and zero at the cutting edge makes it possible to avoid a dark band in the beam at the level of the cut when the lower and upper light sources are activated and their rays are superimposed.
- the double refraction experienced by the rays entering the upper and lower blades 18 has the effect of slightly displacing the second apparent foci of the upper 2 and lower 12 reflectors. This phenomenon is taken into account in the determination of the location of the second common focus of the reflectors and / or in an adaptation of the ellipsoidal reflector (s).
- the curved profile of the rear surface of the lower blade 18 makes it possible to recover certain rays that would otherwise be lost, despite the double refraction imposed by the blade in question.
- a ray reflected by the lower reflector 18 and directed so as to meet the optical axis in front of the focus 6 with a large angle can exit the useful surface of the lens and be lost.
- Such a radius such as the radius 28 shown in FIG. figure 1 , despite the double refraction of the blade with a large angle of incidence, can be directed outside the lens 10. This situation is illustrated by the dotted line 32 which corresponds to the incident ray 28 which would be refracted by a hypothetical blade 18 which have a flat rear surface perpendicular to the optical axis, this surface being also represented by the dotted line 30.
- a profiled surface such as that illustrated in FIG. figure 1 has the consequence that such a ray meets the blade 18 with a greater angle of incidence.
- the spoke 28 is further refracted by the blade so as to meet the lens and participate in the illumination beam.
- This measurement is particularly useful because of the larger size of the reflector used for the "road" function which makes some of the rays it reflects have a large angle with respect to the optical axis.
- the figure 2a is an illustration of a conventional lighting module essentially comprising an upper reflector 102 providing the "code” function, a lower reflector (not shown) providing additional lighting for the "road” function, an aspheric lens 110 and a reflective surface or “reflecting folder” 134 disposed at the junction plane of two reflectors.
- This embodiment differs from that of the figure 1 in particular in that the planes delimiting the upper and lower reflectors, respectively, are not coincidental but form a relative inclination angle.
- the figure 2b is an enlarged side view of the reflective surface or "reflective folder” whose end (surrounded in the circle) acts as a folder 117. We note the non-zero thickness of the folder.
- the figure 3a is an illustration of a lighting module according to the invention, similar to the conventional module of the figure 2a with the difference that the reflecting surface 34 is shorter and ends with a junction surface 17 between an upper blade 16 and a lower blade 18 as described above in relation to the figure 1 .
- the figure 3b is an enlarged view of the reflecting surface 34 and the junction surface forming the folder of almost zero thickness or zero.
- the figure 3b is an alternative to the air wedge as disclosed in the figure 1 . This is to provide that the wafer of at least one of the two blades 16 and 18 is not rigorously flat so as to avoid molecular adhesion of the materials and also to predict the presence of air. Other alternatives to these measurements are possible in order to obtain a diopter, such as the presence of a draft of any shape at the edge of at least one of the two blades.
- the reflective surface 34 disposed in the junction plane of the upper and lower reflectors has not been shown in FIG. figure 1 for simplicity of presentation. This reflective surface has the role of forming an optical separation between the upper and lower parts and, similarly to the folder, to reflect the secondary rays to direct them to the corresponding half of the lens.
- the device of the figure 3a is illustrated in a more complete way and from another angle to the figure 4 .
- the module comprises an upper reflector 2 consisting of two ellipsoidal portions fused with each a light source 4, a lower reflector 12 also ellipsoidal with a single light source 14, a reflecting surface 34 disposed at the junction plane of the two reflectors 2 and 12, an upper blade 16, a lower blade 18 contiguous with the upper blade and an aspherical lens 10. It is observed that the lower blade 18 has a curved rear surface and a front surface similarly curved. The curved front surface makes it possible to increase the refraction of the spokes coming out of the blade that enter the blade in question with a large angle of incidence.
- FIG. figure 5 The photometric image of a lighting module according to the invention and operating in "code” mode is illustrated in FIG. figure 5 . It includes isolux curves illustrating the image projected at a given distance from the module. The horizontal axis corresponds to the horizon or a zero inclination. The vertical axis indicates slope inclination. We observe quite clearly the cut of the projected image slightly above the horizon, with a lower cut on the left compared to the right.
- the photometric image of a lighting module according to the invention and the lighting function in "code” mode is illustrated in "road” mode at the figure 6 .
- the isolux curves show only a very slight irregularity at the cutoff line (visible at the figure 5 ), thereby showing the effectiveness of the folder and the very low or almost no loss of lighting at the cut caused by a folder of very small thickness.
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Abstract
Description
L'invention a trait à un module optique d'éclairage pour projecteur automobile. Le module optique comprend typiquement une source lumineuse, un réflecteur et une lentille, les rayons émis pas la source lumineuse depuis le premier foyer du réflecteur sont réfléchis essentiellement vers le second foyer du réflecteur. L'invention a trait également à un projecteur préférentiellement pour véhicules automobiles et comprenant un pareil module.The invention relates to an optical lighting module for an automotive projector. The optical module typically comprises a light source, a reflector and a lens, the rays emitted by the light source from the first focus of the reflector are reflected substantially toward the second focus of the reflector. The invention also relates to a projector preferably for motor vehicles and comprising such a module.
Les modules d'éclairage équipés d'une source ou plusieurs sources lumineuses du type à diode électroluminescente comprennent typiquement une source lumineuse, un réflecteur de section ellipsoïdale et une lentille. De tels modules sont connus, à titre d'exemple, du document de brevet
Généralement, dans un projecteur elliptique, la coupure peut être assurée par un cache qui est formé d'une plaque verticale de profil adapté et qui est interposé axialement entre le réflecteur elliptique et la lentille convergente, à proximité du second foyer du réflecteur. Le cache permet d'occulter les rayons lumineux issus de la source lumineuse et réfléchis par le réflecteur vers la partie inférieure du plan focal de la lentille convergente, et qui seraient, en l'absence du cache, émis par le projecteur au-dessus de la coupure. Un inconvénient majeur du cache est qu'une partie importante de l'énergie lumineuse émise par la source se dissipe dans la face arrière du cache.Generally, in an elliptical projector, the cut can be provided by a cover which is formed of a vertical plate of suitable profile and which is interposed axially between the elliptical reflector and the convergent lens, near the second focus of the reflector. The cache makes it possible to mask the light rays coming from the light source and reflected by the reflector towards the lower part of the focal plane of the convergent lens, and which, in the absence of the cover, would be emitted by the projector above the cut. A major disadvantage of the cache is that a large part of the light energy emitted by the source is dissipated in the rear face of the cache.
Une construction intéressante d'un module optique tel que décrit ci-avant et pouvant assurer la double fonction « code » et « route » est décrite dans le document de brevet sus mentionné. Elle comprend deux réflecteurs demi-plan disposés de manière opposée et ayant leurs seconds foyers en commun. Dans le cas de l'enseignement du document de brevet
Dans le document de brevet
Dans le document de brevet
L'invention a pour objectif de proposer un module d'éclairage qui pallie au moins un des problèmes sus mentionnés. Plus particulièrement, elle a pour objectif de proposer un module d'éclairage avec plieuse dont la coupure est précise et facile à réaliser, plus particulièrement encore une plieuse d'épaisseur très faible ou quasi-nulle.The invention aims to provide a lighting module that overcomes at least one of the aforementioned problems. More particularly, it aims to provide a lighting module with a folder whose cut is precise and easy to achieve, more particularly a folder of very small thickness or almost zero.
L'invention consiste en un module optique pour dispositif d'éclairage de véhicule automobile, comprenant: un réflecteur avec un premier foyer pour une source lumineuse, un second foyer et un axe optique passant par le premier et le second foyer dudit réflecteur; un élément dioptrique du type lentille convergente disposé sur l'axe optique du réflecteur de sorte à recevoir les rayons lumineux de ladite source lumineuse depuis une zone correspondant au second foyer dudit réflecteur et à émettre un faisceau lumineux; une surface dite plieuse disposée à proximité du second foyer dudit réflecteur, ladite plieuse étant apte à réfléchir une partie des rayons réfléchis par le réflecteur vers une partie de l'élément dioptrique; où ladite plieuse est formée par un dioptre apte à soumettre à une réflexion totale les rayons réfléchis par le réflecteur le rencontrant.The invention consists of an optical module for a motor vehicle lighting device, comprising: a reflector with a first focus for a light source, a second focus and an optical axis passing through the first and second focus of said reflector; a dioptric element of the convergent lens type arranged on the optical axis of the reflector so as to receive the light rays of said light source from an area corresponding to the second focus of said reflector and to emit a light beam; a so-called bending surface disposed near the second focus of said reflector, said bender being adapted to reflect a portion of the rays reflected by the reflector towards a portion of the dioptric element; wherein said folder is formed by a diopter capable of subjecting to total reflection the rays reflected by the reflector meeting it.
Cette construction est particulièrement intéressante car la réflexion assurée par un dioptre est sans perte. De plus, la réalisation d'un dioptre en guise de plieuse constitue une simplification de réalisation par rapport aux surfaces réfléchissantes connues. La lentille convergente possède un foyer de convergence positionnée environ au second foyer du réflecteur, de manière à ce que l'agencement du réflecteur et de la lentille soit tel qu'un rayon passant par le second foyer du réflecteur ressorte de la lentille parallèlement à l'axe optique du module optique.This construction is particularly interesting because the reflection provided by a diopter is lossless. In addition, the embodiment of a dioptre as a folder is a simplification of realization compared to known reflecting surfaces. The converging lens has a focal point positioned about the second focus of the reflector, so that the arrangement of the reflector and the lens is such that a ray passing through the second focus of the reflector emerges from the lens parallel to the reflector. optical axis of the optical module.
Selon un mode avantageux de l'invention, le dioptre est généralement plan et est généralement aligné avec l'axe optique du réflecteur.According to an advantageous embodiment of the invention, the diopter is generally plane and is generally aligned with the optical axis of the reflector.
Selon un autre mode avantageux de l'invention, le dioptre est formé par la surface séparant un milieu transparent solide et un milieu constitué par de l'air.According to another advantageous embodiment of the invention, the diopter is formed by the surface separating a solid transparent medium and a medium consisting of air.
Selon un encore autre mode avantageux de l'invention, le module comprend deux dioptres formés par une couche d'air entre deux matériaux transparents. Cette construction permet d'assurer une réflexion sur deux faces.According to yet another advantageous embodiment of the invention, the module comprises two diopters formed by an air layer between two transparent materials. This construction makes it possible to provide two-sided reflection.
Selon un encore autre mode avantageux de l'invention, le module comprend une première lame en matériau transparent disposée de manière à présenter une tranche généralement plane et généralement alignée avec l'axe optique du réflecteur, la surface séparant le matériau transparent et l'air formant le dioptre.According to another advantageous embodiment of the invention, the module comprises a first blade of transparent material arranged to have a generally flat wafer and generally aligned with the optical axis of the reflector, the surface separating the transparent material and the air forming the diopter.
Selon un encore autre mode avantageux de l'invention, le module comprend une deuxième lame en matériau transparent avec une tranche superposée à la tranche de la première lame de manière à former une couche d'air entre lesdites première et seconde lames, la surface séparant le matériau transparent de ladite seconde lame et l'air formant un deuxième dioptre. Etant donné que la couche d'air peut être extrêmement fine, la plieuse double face résultant de ces deux dioptres peut être d'une épaisseur très fine, voire nulle au bord de coupure, ce qui améliore grandement l'homogénéité de la puissance d'éclairage au niveau de la coupure en mode d'éclairage « route ».According to another advantageous embodiment of the invention, the module comprises a second blade of transparent material with a wafer superimposed on the edge of the first blade so as to form an air layer between said first and second blades, the separating surface the transparent material of said second blade and the air forming a second diopter. Since the air layer can be extremely thin, the double-sided folder resulting from these two dioptres can be of a very thin thickness, or even zero at the cutting edge, which greatly improves the homogeneity of the power of lighting at the cut-off in "road" lighting mode.
Selon un encore autre mode avantageux de l'invention, la couche d'air est formée par un angle de dépouille d'au moins une des première et deuxième lames.According to yet another advantageous embodiment of the invention, the air layer is formed by a draft angle of at least one of the first and second blades.
Selon un encore autre mode avantageux de l'invention, la couche d'air est en forme de coin dont la pointe est disposée au niveau du second foyer du réflecteur. Cette construction de la couche d'air assure une épaisseur nulle de la plieuse au niveau du bord de coupure, ce qui constitue une amélioration de l'image photométrique au niveau du bord de coupure en mode d'éclairage « route ».According to yet another advantageous embodiment of the invention, the air layer is wedge-shaped whose tip is disposed at the second focus of the reflector. This construction of the air layer ensures a zero thickness of the folder at the cutoff edge, which is an improvement of the photometric image at the cutoff edge in "road" lighting mode.
Selon un encore autre mode avantageux de l'invention, la couche d'air est formée par une non planéité de la tranche d'au moins une des première et deuxième lames. Cette construction alternative de la couche d'air est également très intéressante car elle peut conférer une épaisseur très mince et constante à la plieuse tout en étant assez simple à mettre en oeuvre.According to yet another advantageous embodiment of the invention, the air layer is formed by non-flatness of the wafer of at least one of the first and second blades. This alternative construction of the air layer is also very interesting because it can confer a very thin and constant thickness to the folder while being quite simple to implement.
Selon un encore autre mode avantageux de l'invention, le réflecteur est un premier réflecteur concave, par exemple en forme d'une demi coquille, et le module comprend un deuxième réflecteur concave, par exemple en forme d'une demi coquille, opposé audit premier réflecteur, ledit deuxième réflecteur ayant un premier foyer pour une source lumineuse, un second foyer confondu avec le second foyer dudit premier réflecteur et un axe optique passant par ledit premier et ledit second foyer. Selon un exemple simple de réalisation chaque réflecteur concave est délimité en direction de l'autre réflecteur par un plan passant par le premier et le deuxième foyer.According to another advantageous embodiment of the invention, the reflector is a first concave reflector, for example in the form of a half-shell, and the module comprises a second concave reflector, for example in the form of a half shell opposite said first reflector, said second reflector having a first focus for a light source, a second focus coinciding with the second focus of said first reflector and an optical axis passing through said first and said second focus. According to a simple example of embodiment each concave reflector is delimited in the direction of the other reflector by a plane passing through the first and the second focus.
Selon un encore autre mode avantageux de l'invention, le ou au moins un des dioptres est approximativement dans le plan passant par les premier et second foyers du réflecteur correspondant et délimitant ledit réflecteur. Le réflecteur correspondant signifie le réflecteur réfléchissant la lumière qui va ensuite être partiellement réfléchie par le dioptre. Dans le cas où les plans délimitant les premiers et deuxième réflecteurs sont confondus, le ou les dioptres sont approximativement parallèles et dans ledit plan. Dans le cas, où les plans délimitant les premier et deuxième réflecteurs forment un angle, les dioptres sont dans les plans respectifs et correspondants.According to another advantageous embodiment of the invention, the or at least one of the diopters is approximately in the plane passing through the first and second foci of the corresponding reflector and delimiting said reflector. The corresponding reflector means the reflector reflecting the light which will then be partially reflected by the diopter. In the case where the planes delimiting the first and second reflectors coincide, the diopter or diopters are approximately parallel and in said plane. In the case where the planes delimiting the first and second reflectors form an angle, the diopters are in the respective and corresponding planes.
Selon un encore autre mode avantageux de l'invention, la deuxième lame comprend une surface dirigée vers le deuxième réflecteur incurvée de manière à présenter un angle d'incidence plus important par rapport à un plan perpendiculaire à l'axe optique dudit deuxième réflecteur. Cette mesure permet de récupérer certains rayons qui seraient sinon perdus. Elle permet d'augmenter le rendement d'éclairage du module.According to another advantageous embodiment of the invention, the second blade comprises a surface facing the second reflector curved so as to have a greater angle of incidence relative to a plane perpendicular to the optical axis of said second reflector. This measure makes it possible to recover certain rays that would otherwise be lost. It increases the lighting efficiency of the module.
Selon un encore autre mode avantageux de l'invention, la surface de la deuxième lame, dirigée vers le deuxième réflecteur présente un profil courbe se rapprochant dudit réflecteur au fur et à mesure que l'on s'éloigne de son axe optique.According to another advantageous embodiment of the invention, the surface of the second blade, directed towards the second reflector has a curved profile approaching said reflector as one moves away from its optical axis.
Selon un encore autre mode avantageux de l'invention, au moins une des première et deuxième lames présente un profil extérieur généralement circulaire correspondant approximativement au profil extérieur du réflecteur correspondant.According to another advantageous embodiment of the invention, at least one of the first and second blades has a generally circular outer profile corresponding approximately to the outer profile of the corresponding reflector.
L'invention consiste également en un projecteur pour véhicule automobile comprenant un module tel que décrit ci-avant.The invention also consists of a motor vehicle headlight comprising a module as described above.
D'autres caractéristiques et avantages de la présente invention seront mieux compris à l'aide de la description et des dessins parmi lesquels :
- La
figure 1 est une représentation schématique en coupe d'un module d'éclairage selon l'invention, illustrant le principe de fonctionnement d'un point de vue optique. - La
figure 2a est une vue en perspective simplifiée d'un module d'éclairage comportant une plieuse classique. - La
figure 2b est une vue agrandie de la plieuse du module de lafigure 2a . - La 3a est une vue en perspective simplifiée d'un module d'éclairage selon l'invention.
- La
figure 3b est une vue agrandie de la plieuse du module de lafigure 3a . - La
figure 4 est une vue en perspective simplifiée d'un module d'éclairage selon l'invention. - La
figure 5 est une représentation photométrique de l'image du faisceau d'un module selon l'invention en mode « code » avec coupure. - La
figure 6 est une représentation photométrique de l'image du faisceau d'un module selon l'invention en mode « route » avec coupure.
- The
figure 1 is a schematic representation in section of a lighting module according to the invention, illustrating the principle of operation from an optical point of view. - The
figure 2a is a simplified perspective view of a lighting module comprising a conventional folder. - The
figure 2b is an enlarged view of the folding module of thefigure 2a . - The 3a is a simplified perspective view of a lighting module according to the invention.
- The
figure 3b is an enlarged view of the folding module of thefigure 3a . - The
figure 4 is a simplified perspective view of a lighting module according to the invention. - The
figure 5 is a photometric representation of the beam image of a module according to the invention in "code" mode with cutoff. - The
figure 6 is a photometric representation of the image of the beam of a module according to the invention in "road" mode with cutoff.
Les modes de réalisation de l'invention sont illustrés dans les figures et décrits ci-après par rapport à une position de montage du dispositif dans un véhicule en qualité de projecteur. Ce type d'application bien que prépondérant n'est pas limitatif. Les termes employés tels que « horizontal », « vertical », « haut », « bas », « supérieur(e) », « inférieur(e) », « avant »et « arrière » par exemple, décrivant les positions des différents éléments ne sont pas à interpréter d'une manière absolue mais bien relative, décrivant ainsi les positions des éléments par rapport à leur disposition sur les figures. Les dispositifs d'éclairage décrits pourraient être montés dans d'autres positions et/ou pour d'autres applications.Embodiments of the invention are illustrated in the figures and described hereinafter with respect to a mounting position of the device in a vehicle as a projector. This type of application although preponderant is not limiting. Terms used such as "horizontal", "vertical", "high", "low", "upper", "lower", "forward" and "backward", for example, describing the positions of different elements are not to be interpreted in an absolute but relative manner, thus describing the positions of the elements with respect to their arrangement in the figures. The described lighting devices could be mounted in other positions and / or for other applications.
De plus, les positions relatives des différents éléments optiques tels que les sources lumineuses, les réflecteurs et les lentilles exprimées pour la simplicité de compréhension par alignement des axes optiques et/ou correspondance des foyers respectifs ne sont pas à interpréter de manière exacte dans la mesure où de légères variations sont envisageables voire souhaitables en vue, entre autres, de corriger le caractère non parfait et certaines aberrations optiques des éléments optiques ou d'obtenir certains effets supplémentaires.In addition, the relative positions of the various optical elements such as light sources, reflectors and lenses expressed for simplicity of understanding by alignment of the optical axes and / or correspondence of the respective foci are not to be interpreted accurately in the measurement where slight variations are possible or even desirable in order, inter alia, to correct the non-perfect character and some optical aberrations of the optical elements or to obtain some additional effects.
Un module d'éclairage selon l'invention est illustré en coupe à la
Une première lame en matériau transparent 16 est disposée en face du réflecteur supérieure 2, transversalement à l'axe optique 8 de manière à présenter une tranche inférieure généralement plane et dans le plan de séparation des deux réflecteurs. Une seconde lame en matériau transparent 18 est disposée en face du réflecteur inférieur 12, également transversalement à l'axe optique 8 de manière à présenter une tranche supérieure généralement plane et dans le plan de séparation des deux réflecteurs. La lame supérieure 16 est d'épaisseur sensiblement constante et est préférentiellement perpendiculaire à l'axe optique 8. La lame inférieure 18 présente une épaisseur variable, à savoir que la face avant est essentiellement perpendiculaire à l'axe optique et la face arrière présente un profil se rapprochant du réflecteur inférieur 12 au fur et à mesure que l'on s'éloigne de l'axe optique 8. L'épaisseur de la lame inférieure 18 est donc variable. Les épaisseurs des lames supérieure et inférieure sont essentiellement identiques et les surfaces avant des deux lames sont alignées avec le foyer 6.A first blade of
La zone de contact apparent des deux lames 16 et 18 est illustrée dans la vue agrandie de cette zone. On observe que la tranche de chacune des deux lames présente un angle de dépouille de sorte à former un coin d'air dont la pointe est dirigée vers l'avant et correspond au foyer 6. L'angle de dépouille est typiquement de l'ordre de 1°, typiquement dans une plage allant de 0.5° à 3°, préférentiellement de 0.5° à 2°, plus préférentiellement encore de 0.5° à 1.5°. Dans le cas où les plans de séparation des premier et deuxième réflecteurs ne sont pas confondus et forment un angle d'inclinaison relative, on peut choisir un angle de dépouille plus important, pour que l'angle de dépouille corresponde à cet angle d'inclinaison.The apparent contact area of the two
Le coin d'air ainsi formé constitue une couche très mince d'un milieu dont l'indice de réfraction est sensiblement différent de celui des matériaux transparents solides des lames supérieure 16 et inférieure 18. Cette mince couche d'air constitue ainsi avec chacune des lames 16 et 18 un dioptre. En optique, un dioptre est une surface séparant deux milieux transparents d'indices de réfraction différents. Si la lumière se propage en ligne droite dans un milieu homogène et isotrope, elle est déviée lors du passage d'un dioptre: il y a réfraction. Chacun de ces deux dioptres est apte à soumettre les rayons lumineux le rencontrant avec un angle d'incidence supérieur à une valeur donnée à une réflexion et, partant, à jouer le rôle d'une surface réfléchissante.The wedge of air thus formed constitutes a very thin layer of a medium whose refractive index is substantially different from that of the solid transparent materials of the
En optique géométrique, le phénomène de réflexion totale survient lorsqu'un rayon lumineux arrive sur la surface de séparation de deux milieux d'indices optiques différents avec un angle d'incidence supérieur à une valeur critique. Il n'y a alors pas de rayon réfracté transmis et seul subsiste un rayon réfléchi. Ce phénomène n'intervient que lorsque le rayon lumineux incident est dans un milieu d'indice plus grand que l'éventuel rayon réfracté. C'est le cas ici car le matériau de la lame 16 ou 18, typiquement du verre ou du matériau plastique comme du polycarbonate présente un indice de réfraction sensiblement supérieur à l'air. L'angle limite de réfraction est donné par la formule suivante:
Etant donné que l'indice de réfraction du matériau des lames est de l'ordre de 1.5 et que l'indice de réfraction de l'air est de l'ordre de 1, il résulte que l'angle limite de réfraction est de l'ordre de 41°. Cela signifie que les rayons lumineux incidents sur les dioptres avec un angle supérieur à environ 41° seront soumis à une réflexion totale, à l'instar d'une surface réfléchissante.Since the refractive index of the material of the blades is of the order of 1.5 and the index of refraction of the air is of the order of 1, it follows that the refractive limit angle is order of 41 °. This means that light rays incident on the diopters with an angle greater than about 41 ° will be subject to total reflection, like a reflective surface.
La réflexion totale assurée par le dioptre ne présente pratiquement aucune perte à l'inverse d'une surface réfléchissante classique qui présente généralement une perte à la réflexion de l'ordre de 15%. Le passage des rayons au travers des lames 16 et 18 constitue cependant une perte de l'ordre de 10% qui se voit compensée par l'absence de perte à la réflexion.The total reflection provided by the diopter has virtually no loss in contrast to a conventional reflecting surface which generally has a reflection loss of the order of 15%. The passage of rays through the
Divers matériaux plastiques transparents sont envisageables pour les lames, comme par exemple du polyméthacrylate de méthyle (souvent abrégé en PMMA, de l'anglais PolyMethyl MethAcrylate) ou du polycarbonate. Le verre peut également être utilisé en alternative aux matériaux plastiques transparents.Various transparent plastics materials are possible for the blades, such as for example polymethyl methacrylate (often abbreviated to PMMA) or polycarbonate. Glass can also be used as an alternative to transparent plastics.
L'épaisseur de la lame est de l'ordre de quelques millimètres, typiquement de 2 à 15 mm, préférentiellement de 3 à 10 mm, plus préférentiellement encore de 4 à 8 mm.The thickness of the blade is of the order of a few millimeters, typically from 2 to 15 mm, preferably from 3 to 10 mm, more preferably from 4 to 8 mm.
La source lumineuse 4 du réflecteur supérieur 2 bien qu'assimilable à une source quasi-ponctuelle émet des rayons légèrement décentrés par rapport aux rayons principaux émis par le centre de la source. Un rayon dit principal 20 émis par la source 4 est illustré à la
Le dioptre formé la lame 16 et la couche d'air constitue une plieuse 17 qui a pour effet de « replier » les rayons tel que le rayon 24 qui sinon rencontreraient la lentille dans la partie inférieure à un point et avec un angle d'incidence tels qu'ils seraient réfractés en sortie de la lentille dirigé vers le haut et formerait le haut de l'image de projection. La plieuse assure ainsi une fonction de coupure du faisceau projeté par la lentille. Les rayons principaux et secondaires rencontrent et traversent la lentille. Les rayons principaux, tel que le rayon principal 20 illustré, passent par le foyer de la lentille et sortent donc de celle-ci en étant parallèle à l'axe optique 8. Comme les rayons secondaires, tels que le premier 22 et le deuxième 24 rayon secondaire illustrés, passent au-dessus du foyer de la lentille, ils sortent de la lentille en étant incliné vers le bas et forment ainsi le bas de l'image projetée par le module en dessous de la coupure. La coupure dans le faisceau sera nette et va avoir la forme du bord de la lame 16, celle-ci étant positionnée au foyer de la lentille.The diopter formed the
La fonction d'éclairage « code », c'est-à-dire avec coupure, est assurée par le réflecteur supérieur 2 et sa source lumineuse 4, produisant ainsi un faisceau correspondant à l'image photométrique de la
La fonction d'éclairage « route » est assurée par la mise sous tension des sources lumineuses supérieure 4 et inférieure 14. Les rayons émis pas la source lumineuse inférieure 14 viennent s'ajouter à ceux émis pas la source supérieure 4. Similairement à ce qui a été décrit pour le réflecteur supérieur, les mêmes phénomènes ont lieu pour les rayons émis par la source lumineuse inférieure 14 et réfléchis par le réflecteur 12, à la différence près qu'il y a inversion entre les deux moitiés supérieure et inférieure de la lentille. Ceci a pour conséquence que les rayons réfléchis par le réflecteur inférieur 12 qui traversent l'axe optique en avant du foyer et au-dessous du foyer de la lentille sortent de la moitié supérieure de la lentille 10 en étant inclinés vers le haut, ce qui constitue le complément d'éclairage dans le moitié supérieure de l'image projetée, telle qu'illustrée à la
L'épaisseur très faible de la plieuse, en pratique de l'ordre du dixième de millimètre à son épaisseur maximale dans le cas du coin d'air tel que décrit ci-avant (de l'ordre de 0.14 mm pour une lame épaisse de 4 mm ou encore de l'ordre de 0.28 mm pour une lame épaisse de 8 mm), et nulle au bord de coupure permet d'éviter une bande sombre dans le faisceau au niveau de la zone de coupure lorsque les sources lumineuses inférieures et supérieures sont activées et que leurs rayons se superposent.The very small thickness of the folder, in practice of the order of a tenth of a millimeter to its maximum thickness in the case of the air wedge as described above (of the order 0.14 mm for a 4 mm thick blade or on the order of 0.28 mm for a 8 mm thick blade), and zero at the cutting edge makes it possible to avoid a dark band in the beam at the level of the cut when the lower and upper light sources are activated and their rays are superimposed.
Il est à noter que la double réfraction que subissent les rayons entrant dans les lames supérieure 16 et inférieure 18 a pour effet de déplacer légèrement les seconds foyers apparents des réflecteurs supérieur 2 et inférieur 12. Il est tenu compte de ce phénomène dans la détermination de l'emplacement du second foyer commun des réflecteurs et/ou dans une adaptation du ou des réflecteurs ellipsoïdaux.It should be noted that the double refraction experienced by the rays entering the upper and
Le profil courbe de la surface arrière de la lame inférieure 18 permet de récupérer certains rayons qui seraient sinon perdus et ce malgré la double réfraction imposée par la lame en question. Un rayon réfléchis par le réflecteur inférieur 18 et dirigé de sorte à rencontre l'axe optique devant le foyer 6 avec un angle important peut sortir de la surface utile de la lentille et être perdu. Un tel rayon, tel que le rayon 28 illustré à la
La
La
La
La
Il est à noter que la surface réfléchissante 34 disposé dans le plan de jonction des réflecteurs supérieur et inférieur n'a pas été représentée à la
Le dispositif de la
L'image photométrique d'un module d'éclairage conforme à l'invention et fonctionnant en mode « code » est illustrée à la
L'image photométrique d'un module d'éclairage conforme à l'invention et à la fonction d'éclairage en mode « code » est illustrée en mode « route » à la
Claims (15)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0956728A FR2950672B1 (en) | 2009-09-29 | 2009-09-29 | OPTICAL MODULE WITH FOLDER FORMED BY A DIOPTER TRANSPARENT MATERIAL / AIR |
Publications (1)
Publication Number | Publication Date |
---|---|
EP2302292A1 true EP2302292A1 (en) | 2011-03-30 |
Family
ID=42076992
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP10177944A Withdrawn EP2302292A1 (en) | 2009-09-29 | 2010-09-21 | Optical module with folder formed by a transparent material/air dioptre |
Country Status (2)
Country | Link |
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EP (1) | EP2302292A1 (en) |
FR (1) | FR2950672B1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2410238A1 (en) * | 2010-07-19 | 2012-01-25 | Valeo Vision | Optical reflector consisting of a transparent blade with an undercut |
EP2410237A1 (en) * | 2010-07-19 | 2012-01-25 | Valeo Vision | Reflector of the corrected elliptical type |
EP3290774A1 (en) * | 2016-09-06 | 2018-03-07 | Valeo Vision | Lighting module with diffractive screen for motor vehicle |
WO2023031023A1 (en) * | 2021-08-31 | 2023-03-09 | Valeo Vision | Vehicle lamp module, motor vehicle headlamp and motor vehicle |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1357333A2 (en) * | 2002-04-23 | 2003-10-29 | Koito Manufacturing Co., Ltd | Light source unit for vehicular lamp |
EP1666787A1 (en) * | 2004-12-06 | 2006-06-07 | Valeo Vision | Lighting module for vehicle headlamp |
EP2006605A1 (en) * | 2007-06-18 | 2008-12-24 | Valeo Vision | Vehicle headlamp |
EP2006604A1 (en) * | 2007-06-18 | 2008-12-24 | Valeo Vision | Optical module for vehicular lighting device |
-
2009
- 2009-09-29 FR FR0956728A patent/FR2950672B1/en not_active Expired - Fee Related
-
2010
- 2010-09-21 EP EP10177944A patent/EP2302292A1/en not_active Withdrawn
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1357333A2 (en) * | 2002-04-23 | 2003-10-29 | Koito Manufacturing Co., Ltd | Light source unit for vehicular lamp |
EP1666787A1 (en) * | 2004-12-06 | 2006-06-07 | Valeo Vision | Lighting module for vehicle headlamp |
EP2006605A1 (en) * | 2007-06-18 | 2008-12-24 | Valeo Vision | Vehicle headlamp |
EP2006604A1 (en) * | 2007-06-18 | 2008-12-24 | Valeo Vision | Optical module for vehicular lighting device |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2410238A1 (en) * | 2010-07-19 | 2012-01-25 | Valeo Vision | Optical reflector consisting of a transparent blade with an undercut |
EP2410237A1 (en) * | 2010-07-19 | 2012-01-25 | Valeo Vision | Reflector of the corrected elliptical type |
EP3290774A1 (en) * | 2016-09-06 | 2018-03-07 | Valeo Vision | Lighting module with diffractive screen for motor vehicle |
FR3055691A1 (en) * | 2016-09-06 | 2018-03-09 | Valeo Vision | DIFFRACTIVE SCREEN LIGHTING MODULE FOR MOTOR VEHICLE |
CN108302479A (en) * | 2016-09-06 | 2018-07-20 | 法雷奥照明公司 | The lighting module with diffraction screen for motor vehicles |
US10371339B2 (en) | 2016-09-06 | 2019-08-06 | Valeo Vision | Lighting module with diffraction screen for a motor vehicle |
WO2023031023A1 (en) * | 2021-08-31 | 2023-03-09 | Valeo Vision | Vehicle lamp module, motor vehicle headlamp and motor vehicle |
Also Published As
Publication number | Publication date |
---|---|
FR2950672B1 (en) | 2012-11-16 |
FR2950672A1 (en) | 2011-04-01 |
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