FR3045130A1 - The invention relates to the field of lighting and / or light signaling, especially for motor vehicles. - Google Patents

Abstract

The invention relates to an optical module (2) for lighting and / or signaling, in particular for a motor vehicle. Said optical module comprises first and second light sources (6A, 6B) of the laser type, each capable of emitting light radiation; a first conversion device arranged to convert the light radiation of the first source (6A) to white light and a second conversion device (8B), distinct from the first conversion device (8A) and arranged to convert the light radiation of the second source (6B) in white light. Said module also comprises a first optical device and a second optical device contiguous and arranged to receive the white light respectively of the first and second conversion devices (8A, 8B) in order to form a lighting and / or signaling light beam. The invention also relates to a corresponding lighting and / or signaling device.

Description

The invention relates to the field of lighting and / or light signaling, in particular for motor vehicles.

In order to carry out a lighting and / or light-signaling function of a motor vehicle, it is known to mount, in a vehicle body, an optical module which comprises a laser-type light source and an optical device formed by a lens intended for to shape the light from the light source. The optical module also comprises a device for converting coherent light radiation from the laser light source into white light.

Said housing intended to house the optical module comprises a transparent or translucent pane intended to be traversed by the light beam leaving the lens to obtain the desired illumination and / or the desired light signaling. Generally, the lens is hemispherical. The lens is then seen from the outside of the vehicle, in a form of shells, which is unattractive.

It may thus be desirable for aesthetic reasons to design an elongated optical device to obtain a linear style. However, if one attempts to make an elongated lens from a conventional hemispherical lens by adapting its diameter to the desired length and truncating said lens at the top and bottom to obtain the desired elongated shape, not only the obtained lens has a significant depth, which increases the size of the optical module, but in addition it is found that the associated light performance is not satisfactory.

Indeed, the luminous power obtained at the output of such an optical module is not sufficient, in particular along the vertical axis, corresponding to the axis of the height of the lens in the installed state of the optical module in the vehicle. The invention aims to overcome at least one of the disadvantages of the aforementioned prior art.

More particularly, the object of the present invention is to propose a new optical lighting and / or signaling module whose lighting and / or signaling beam shaping part has an elongated shape, the module retaining a bulk limited in depth and sufficient light performance.

Another object of the invention is to propose a new optical lighting and / or signaling module whose operation is secure. For this purpose, the subject of the invention is an optical illumination and / or signaling module, in particular for a motor vehicle, characterized in that said optical module comprises: a first and a second light source, of the laser type, each capable of emitting light radiation; a first conversion device arranged to convert the light radiation of the first source into white light and a second conversion device, distinct from the first conversion device and arranged to convert the light radiation of the second source into white light; a first optical device and a second optical device that are contiguous and arranged to receive white light respectively from the first and second conversion devices in order to form a lighting and / or signaling light beam.

Such an optical module design which comprises at least two light sources facing two contiguous optical devices makes it possible to obtain an overall optical device of elongated shape so as to meet a general aesthetic need of linear appearance, while retaining a reduced footprint and satisfactory light performance.

According to a particular embodiment of the invention, the first optical device comprises a first optical lens and the second optical device comprises a second optical lens which each have an input face and an output face, the input faces being configured for respectively receiving the white light of the conversion device associated with the first source and the white light of the conversion device associated with the second source. The exit faces of said first and second lenses are contiguous with each other.

Due to the fact that the exit faces of the lenses are contiguous, an outside person looking at the optical module visualizes a single elongated lens.

According to an advantageous characteristic of the invention, the exit faces of said first and second lenses are smooth.

According to an advantageous characteristic of the invention, the first optical lens and the second optical lens are formed in one piece.

According to an advantageous characteristic of the invention, the exit face of the first optical lens has a surface continuity with the exit face of the second optical lens.

According to an advantageous characteristic of the invention, the exit face of the first optical lens has continuity of curvature with the exit face of the second optical lens.

According to a particular embodiment of the invention, the first optical device comprises a first reflector and the second optical device comprises a second reflector, said first and second reflectors each having a concavity reflection face turned respectively towards the first and second light sources. for respectively receiving the white light of the conversion device associated with the first source and the white light of the conversion device associated with the second source. The reflection faces of said first and second reflectors are contiguous to each other.

According to an advantageous characteristic of the invention, the optical device comprises a detection system capable of detecting the white light of each of the conversion devices.

The detection system associated with the laser sources makes it possible to detect the failure of the optical module. More particularly, the detection system makes it possible to detect whether the conversion devices are working correctly or not.

According to an advantageous characteristic of the invention, the detection system comprises: a light sensor configured to receive a portion of the light emitted at the output of the first and second conversion devices and to detect at least one physical characteristic of said light, and A separate or common first optical element and second optical element configured to deflect a portion of the rays of light from the first and second conversion devices to the light sensor.

Such a design of the security system makes it possible to position the sensor between the two laser sources.

An emission of light beam that is not adapted in terms of color and / or power can thus be effectively detected with a simple implementation.

According to an advantageous characteristic of the invention, the detection system comprises: a light sensor configured to receive a portion of the light emitted at the output of the first and second conversion devices and to detect at least one physical characteristic of said light, and An optical element located at the junction of the reflection surfaces of the reflectors and configured to deflect a portion of the rays of light from the first and second conversion devices to the light sensor.

According to an advantageous characteristic of the invention, the optical module also comprises a module for comparing the value of said at least one physical characteristic detected with a reference value or a range of reference values.

According to an advantageous characteristic of the invention, the optical module also comprises a control module configured to control the power supply stoppage of the sources as a function of the result of said comparison module.

According to an advantageous characteristic of the invention, the light sensor comprises at least one photodiode, preferably a photodiode of RGB type.

According to an advantageous characteristic of the invention, each of the first and second optical elements comprises a prism forming an input diopter of the white light of the conversion device, a reflection surface of said light coming from the input diopter, and a diopter output of said light from the reflection surface.

According to an advantageous characteristic of the invention, at least one, preferably each, of the first and second optical elements is located on, preferably at the periphery of, the entrance face of one of the first and second lenses. .

The positioning of the optical element in the form of a prism on the periphery of a lens is particularly advantageous in that it allows the optical element to be produced at low cost and makes it possible to send the rays in a direction opposite to that of the light beam of the module. The sensor can thus be mounted on the same plate as other components of the module such as laser sources and conversion devices. The invention also relates to a lighting and / or signaling device for a motor vehicle comprising: a housing comprising a transparent or translucent pane; and an optical module as described above, said optical module being housed in said housing and arranged to emit white light through said window. Other characteristics and advantages of the invention will emerge from the description which follows, which is purely illustrative and not limiting and should be read with reference to the accompanying drawings, in which: - Figure 1 is a schematic representation of a module optical lighting and / or signaling according to a first embodiment of the invention; FIG. 2 is a schematic representation of an optical lighting and / or signaling module according to a second embodiment of the invention.

With reference to the figures, there is shown an optical module 2 for lighting and / or signaling, especially for a motor vehicle. Said optical module is intended to be housed in a housing (not shown) of a lighting and / or signaling device, such as a lighthouse. Said housing has a translucent or transparent pane that the light beam of the optical module is intended to pass through.

Said optical module 2 comprises at least a first and a second light sources 6A, 6B of the laser type. Each laser source 6A, 6B comprises a laser diode and a collimating lens (not shown) associated with the laser diode. Each laser diode produces spatially and temporally coherent radiation. A first conversion device 8A and a second separate conversion device 8B are provided to convert this spatially and temporally coherent radiation into an incoherent white light radiation.

In other words, the first device and the second conversion device 8A, 8B are arranged so that the point of impact of the radiation of the first source 6A on the first conversion device 8A is distant from the point of impact of the radiation of the second source 6B on the second conversion device 8B.

The collimation lens associated with the laser diode makes it possible to collimate the rays of the laser diode on the corresponding conversion device 8A, 8B.

The conversion device 8A, 8B is preferably phosphor which, when excited by the laser beam, emits white light. By way of example, the laser beam of a laser diode may be blue and of a wavelength of the order of 450 nm and the conversion device 8A, 8B may then transform this blue beam into white light. a temperature of about 5500 Kelvin. Other color temperatures are of course possible, especially from 2000 to 6000 Kelvin.

Each source 6A, 6B and each associated conversion device 8A, 8B is housed in a housing 7A, 7B. The conversion device 8A, 8B is disposed on a face of the housing 7A, 7B, called the output face, which is transparent and positioned facing an optical system 10 as detailed below.

The optical system 10 comprises a first optical device and a second optical device contiguous and arranged to receive the white light respectively of the first and the second conversion device 8A, 8B to form a lighting and / or signaling light beam.

According to the embodiment illustrated in FIG. 1, the first optical device comprises a first optical lens 10A and the second optical device comprises a second optical lens 10B.

Said lenses 10A, 10B are arranged with the light sources 6A, 6B to respectively receive the white light of the conversion device 8A associated with the source 6A, and the white light of the conversion device 8B associated with the second source 6B.

The lenses 10A, 10B of the optical device make it possible to shape the rays converted by the conversion devices 8A, 8B and thus to form the lighting beam and / or light signaling beam.

Each conversion device 8A, 8B also has the effect of diffusing the converted light of the corresponding source, in a space delimited by the plane passing through said output face of the housing 7A, 7B, in the direction of the lens 10A, 10B.

Advantageously, said first and second lenses 10A, 10B are formed in one piece. In other words, said lenses 10A, 10B are formed in the same material and integrally.

The exit faces 102A, 102B of said first and second lenses 10A, 10B are contiguous to each other. In another aspect, said exit faces 102A, 102B are smooth.

As illustrated in FIG. 1, the exit face 102A of the first optical lens 10A has a surface continuity with the exit face 102B of the second optical lens 10B.

In particular, the output face 102A of the first optical lens 10A has a continuity of curvature with the output face 102B of the second optical lens 10B. In other words, the tangent considered along the surface of the outlet faces of the two lenses, or the first derivative of the corresponding curve, does not have a value discontinuity at least in the connection zone of said output faces. Said exit faces also do not exhibit, at least in their binding area, inflection points of curvature.

The lenses 10A, 10B thus make it possible to obtain an elongated lens to form an elongated beam which passes through the corresponding window of the housing of the lighting and / or signaling device.

The optical module 2 thus comprises an overall lens of greater width than its height with a small curve compared to a hemispherical lens of diameter corresponding to the desired width. The depth of the optical module is thus limited. The depth of the optical module is considered along an axis parallel to the mean axis of the illumination and / or signaling beam. The width of the lens is considered in a horizontal direction transverse to said mean axis of the illumination beam. For example, the overall lens has a height of about 17 millimeters and a height of about 80 millimeters.

In the example illustrated in the figures, the curvature of the input face 101A of the first lens 10A and the curvature of the input face 101B of the second lens 10B are each turned towards the exit face 102A, 102B of the 10A lens, corresponding 10B. Vis-à-vis an external user, located on the side of the lenses 10A, 10B opposite the sources, said output faces of the lenses 10A, 10B are convex while said corresponding input faces are concave.

According to one embodiment, each lens 10A, 10B is of the thick lens type.

In the example illustrated in FIG. 1, the light source 6A, 6B, the associated conversion device 8A, 8B and the corresponding lens 10A, 10B are aligned along an axis 12A, 12B.

The optical module also includes a security device which makes it possible to prevent the emission of a light beam whose color and / or power characteristics do not correspond to the required characteristics.

The security device comprises a detection system 3 capable of detecting the white light of each of the conversion devices 8A, 8B.

The detection system 3 comprises a light sensor 16 configured to receive a portion of the light emitted at the output of each of the conversion devices 8A, 8B and to detect at least one physical characteristic of said light representative of its power and / or the composition of its color.

The light sensor 16 is preferably mounted on a plate (not shown) on which the laser sources 6A, 6B are also mounted.

In the example illustrated in FIG. 1, the detection system 3 also comprises, for each conversion device 8A, 8B, an optical element 14A, 14B configured to deflect rays of the white light obtained by the conversion device 8A, 8B corresponding to the light sensor 16. Advantageously, each associated optical element 14A, 14B is disposed at a distance from said axis 12A, 12B, between the corresponding conversion device 8A, 8B and the first, respectively second, optical lens 10A, 10B.

A ray coming from the conversion device 8A, 8B and which enters the optical element 14A, 14B is reflected by being deflected towards the sensor 16. In particular, said light sensor 16 is arranged between the two sources 6A, 6B so as to receiving at least a portion of the rays reflected by the optical elements 14A, 14B.

In general, the optical element 14A, 14B is configured to deflect the rays of the white light from the conversion device 8A, 8B towards the sensor 16 in a direction essentially opposite to that of the lighting and / or signaling light beam. .

Advantageously, said light sensor 16 comprises at least one photodiode, preferably a photodiode of RGB type. A photodiode of RGB type is composed of three photodiodes, namely a photodiode for the detection of red radiation, a photodiode for the detection of green radiation and a photodiode for the detection of blue radiation.

As a variant, it is also possible for the light sensor to comprise at least two photodiodes arranged between the two sources so as to receive, at least one part of the rays reflected by one of the optical elements 14A, and, other, at least a portion of the rays reflected by the other optical element 14B.

As illustrated in FIG. 1, the input face 101A, 101B of each lens 10A, 10B is provided with such an optical element 14A, 14B in the form of a prism. Similarly to the lens 10A, 10B, it is made of transparent or translucent material. It may have come from material with the lens, that is to say the same material and having a continuity of material with the lens. It can also be attached to the lens, in particular by gluing, clipping or any other means known in itself to those skilled in the art. Each optical element 14A, 14B protrudes from the input face 101A, 101B of the lens 10A, 10B.

In a particular aspect, the optical element 14A, 14B forms a singularity at the periphery of the lens 10A, 10B. Indeed, its volume can be reduced considering that only a small portion of the spokes of the conversion device 8A, 8B must be diverted to the sensor. According to one embodiment, at least one, preferably each, of the optical elements 14A, 14B is arranged on the optical device 10 to act as a polarizer, preferably in rotation, for the positioning of said optical device 10 in the device housing. lighting and / or signaling. The module may comprise a support (not shown) with a notch for receiving at least a portion of the optical element 14A, 14B.

Each prismatic optical element 14A, 14B has a first diopter forming an input face 141A, 141B directed towards the conversion device 8A, 8B. It also comprises a reflection face 142A, 142B preferentially formed by a second diopter, and an exit face 143A, 143B formed by a third diopter. Reflection surface 142A, 142B is a diopter capable of reflecting light from input diopter 141A, 141B by total reflection.

Part of the rays emitted by the conversion devices 8A, 8B meet the input face 141A, 141B of the optical element 14A, 14B. This part corresponds in this case to rays directed towards the periphery of the entry face 101 A, 101B of the lens 10A, 10B. More particularly this part corresponds to a limited sector of the rays directed towards the periphery of the entrance face of the lens, this sector being able to be limited to 20 °, preferably to 10 °. These rays meeting the input face 141A, 141B are refracted to then meet the reflection face 142A, 142B. The spokes are reflected and leave the element by the exit face 143A, 143B. The deviated rays are directed towards the light sensor 16.

The security system also comprises a comparison module 17 configured to compare the value of said at least one physical characteristic detected by the light sensor 16 with a reference value or a range of reference values corresponding to a value or a range of values. allowable light values at the output of the conversion devices.

The detection system 3 also comprises a control module 18 configured to control the power supply stoppage of the sources 6A, 6B as a function of the result of said comparison module 17. The comparison 17 and control modules 18 can be made in the form of a control module 18. of electronic components mounted with the light sensor 16, on an electronic circuit, for example a printed circuit.

In case of failure of at least one of the conversion devices 8A, 8B, the radiation emitted by the corresponding laser source 6A, 6B is no longer properly diffused and converted into white light. This means that less light, or even more light at all, is received by the optical element 14A, 14B and the sensor 16. The absence or decrease of light detection at the sensor is thus an indicator of failure at the conversion device 8A, 8B as long as the laser source 6A, 6B is active. Such a failure is likely to let at least a portion of the coherent radiation lasers to the output of the optical module and, therefore, may cause burns especially in the eyes of people in the vicinity of the optical module.

The security device of the optical module 2 thus makes it possible to control the laser sources and stop their operation when the light sensor 16 detects an anomaly.

According to another embodiment illustrated in FIG. 2, the first optical device comprises a first reflector 40A and the second optical device comprises a second reflector 40B. The characteristics of the sources 8A, 8B, their housings 7A, 7B and the conversion devices 6A, 6B, described above are applicable to this embodiment.

Said first and second reflectors each having a reflection face 401 A, 401B of concavity turned respectively towards the first and second light sources to receive respectively the white light of the conversion device 8A associated with the first source 6A and the white light of the device 8B conversion associated with the second source 6B.

The reflection faces 401A, 401B of said first and second reflectors are contiguous with each other.

Similarly to the embodiment illustrated in FIG. 1, the optical module 2 according to the embodiment illustrated in FIG. 2 comprises a detection system 3 able to detect the white light of each of the conversion devices 8A, 8B. The detection system 3 comprises a light sensor 16 configured to receive a portion of the light emitted at the output of the first and second conversion devices 8A, 8B and to detect at least one physical characteristic of said light.

The optical module according to the embodiment illustrated in FIG. 2 comprises an optical element 44 which is located at the junction of the reflection surfaces of the reflectors and configured to deflect a portion of the rays of light coming from the first and second conversion devices 8A. , 8B to the light sensor 16. This optical element 44 may be a prism or a reflector (*** Please confirm ***).

The security system 3 also comprises a comparison module 17 configured to compare the value of said at least one physical characteristic detected by the light sensor 16 with a reference value or a range of reference values corresponding to a value or a range. allowed light values at the output of the conversion devices.

The detection system 3 also comprises a control module 18 configured to control the power supply stoppage of the sources 6A, 6B as a function of the result of said comparison module 17. The comparison 17 and control modules 18 can be made in the form of a control module 18. of electronic components mounted with the light sensor 16, on an electronic circuit, for example a printed circuit.

The first and second reflectors and corresponding first and second sources are arranged so that the rays from the conversion devices which impact the reflectors are reflected by the corresponding reflective surface parallel to each other. In particular, the reflectors are configured so that the rays reflected by one of the reflectors are parallel to the rays reflected by the other reflector.

Whatever the embodiment, it can be provided that the optical module comprises transmission means configured to transmit information corresponding to a device for controlling the position of one or each conversion device for the case where one or each of the conversion devices would be poorly positioned.

The present application contemplates covering all the adaptations and variations of the embodiments described above. Moreover, the term "comprising" does not exclude other elements or steps. In addition, features or steps that have been described with reference to one of the embodiments set forth above may also be used in combination with other features or steps of other embodiments set forth above. Note that it is necessary to include in the scope of the patent all the modifications envisaged above insofar as they form part of the contribution of the inventors to the prior art.

Claims (16)

1. Optical module (2) lighting and / or signaling, in particular for a motor vehicle, characterized in that said optical module (2) comprises: a first and a second sources (6A, 6B) of light, of the type laser, each capable of emitting light radiation; a first conversion device (8A) arranged to convert the light radiation of the first source (6A) into white light and a second conversion device (8B), distinct from the first conversion device (8A) and arranged to convert the radiation; light from the second source (6B) in white light; a first optical device and a second optical device joined together and arranged to receive the white light respectively of the first and second conversion devices (8A, 8B) in order to form a lighting and / or signaling light beam. Optical module (2) according to claim 1, characterized in that the first optical device comprises a first optical lens (10A) and the second optical device comprises a second optical lens (10B) each having an input face ( 101A, 101B) and an output face (102A, 102B), the input faces being configured to receive respectively the white light of the conversion device (8A) associated with the first source (6A) and the white light of the conversion device (8B) associated with the second source (6B), and in that the output faces (102A, 102B) of said first and second lenses are contiguous with each other. 3. Optical module (2) according to claim 2, characterized in that the output faces (102A, 102B) of said first and second lenses are smooth. 4. Optical module (2) according to one of claims 2 or 3, characterized in that the first optical lens (10A) and the second optical lens (10B) are formed in one piece. 5. Optical module (2) according to one of claims 2 to 4, characterized in that the output face (102A) of the first optical lens (10A) has a surface continuity with the output face (102B) of the second optical lens (102B). 6. Optical module (2) according to one of claims 2 to 5, characterized in that the output face (102A) of the first optical lens (10A) has a continuity of curvature with the output face (102B) of the second optical lens (10B). 7. Optical module (2) according to claim 1, characterized in that the first optical device comprises a first reflector (40A) and the second optical device comprises a second reflector (40B), said first and second reflectors each having a face of reflection (401 A, 401 B) of concavity turned respectively to the first and second light sources for respectively receiving the white light of the conversion device (8A) associated with the first source (6A) and the white light of the conversion device (8B) ) associated with the second source (6B), and in that the reflection faces (401A, 401B) of said first and second reflectors are contiguous with each other. Optical module (2) according to one of the preceding claims, characterized in that the optical device (10) comprises a detection system (3) capable of detecting the white light of each of the conversion devices (8A, 8B). . Optical module (2) according to claim 8, characterized in that the detection system (3) comprises: a light sensor (16) configured to receive a portion of the light emitted at the output of the first and second converting (8A, 8B) and detecting at least one physical characteristic of said light, and, • a first or second optical element (44; 14A) and a second optical element (14B), separate or common, configured to deflect a portion of the light from the first and second conversion devices (8A, 8B) to the light sensor (16). 10. Optical module (2) according to claims 7 and 8, characterized in that the detection system (3) comprises: • a light sensor (16) configured to respectively receive a portion of the light emitted at the output of the first and second conversion devices (8A, 8B) and detecting at least one physical characteristic of said light, and, • an optical element (44) located at the junction of the reflecting surfaces of the reflectors and configured to deflect a portion of the rays of light from the first and second conversion devices (8A, 8B) to the light sensor (16). Optical module (2) according to claim 9 or 10, characterized in that the optical module (2) also comprises a module (17) for comparing the value of said at least one physical characteristic detected with a reference value or a range of reference values. Optical module (2) according to claim 11, characterized in that the optical module (2) also comprises a control module (18) configured to control the power supply stop (6A, 6B) as a function of the result of said comparison module (17). 13. Optical module (2) according to one of claims 9 to 12, characterized in that the light sensor (16) comprises at least one photodiode, preferably a photodiode type RGB. 14. Optical module (2) according to one of the preceding claims, characterized in that each of the first and second optical elements (14A, 14B) comprises a prism forming an input diopter (141 A, 141 B) of the light white of the conversion device (8A, 8B), a reflecting surface (142A, 142B) of said light coming from the input diopter (141A, 141B), and an output diopter (143A, 143B) of said light from the reflection surface (142A, 142B). 15. Optical module (2) according to one of claims 9 or 11 to 14 taken in combination of one of claims 2 to 6, characterized in that, at least one, preferably each, of the first and second optical elements (14A, 14B) are located on, preferably at the periphery of, the input face (101A, 101B) of one of the first and second lenses (10A, 10B). 16. A lighting and / or signaling device for a motor vehicle comprising: a housing comprising a transparent or translucent pane; and an optical module (2) according to one of the preceding claims, said optical module being housed in said housing and arranged to emit white light through said window.