Patent Application
20140153272
This application claims priority to French Application No. 1261511 filed Nov. 30, 2012.
1. Field of the Invention
The present invention relates to a lighting and/or signaling device, notably for a motor vehicle. It is intended in particular for signaling lights and/or daytime running lights, although it is not in any way restricted to such applications.
2. Description of the Related Art
In this field, it is known that manufacturers wish to add distinctive features, notably using visibly original elements, so that they more readily stand out from the competition.
Thus, devices equipped with a light source, generally a light emitting diode, and a light guide in the form of a string or a layer from which light is emitted in a free geometric pattern, are known. The light travels along the guide by total internal reflection until it reaches an outlet face, which projects the light in such a way that it can be seen by the vehicles behind or in front. In the automotive field, such devices are well-received because they are able to offer a wide variety of shapes and types of light.
These devices nowadays use light sources comprising a support used to supply electrical current to a single light emitting diode, referred to as a single-point light source. The sources have limited light intensity.
That being the case, their emission surface area is small, measuring around 1 mm in diameter. In the case of light guides with a surface configuration, the inlet surface for the light is along an edge face of the guide, of similar thickness. It is therefore conceivable to incorporate a plurality of single-point light sources along the inlet face thus making it possible to obtain good light intensity.
In the case of a guide in the form of a string having a cross section the desired diameter of which is around ten millimeters or so, increasing the number of single-point light sources in order to achieve the desired level of brightness has its limits. Specifically, it is a complex matter to couple a great many sources to the guide, and the brightness losses generated as a result of coupling difficulties also limit the benefit of such a solution.
The invention therefore seeks to obtain a device, equipped with a light guide, particularly in the form of a string, that is capable of achieving the brightness criteria set by the regulations while at the same time limiting the number of light sources.
To do that, the lighting and/or signaling device, notably for a motor vehicle, according to the invention, comprises at least one light source and one light guide, the source comprising a support and a plurality of light emitting components arranged on the support so as to emit a beam of light, the device being configured to direct the beam toward the guide, in which device the support is a printed circuit and/or the light emitting components are light emitting diodes, in which device the light emitting components are arranged in such a way as to define an emission surface for the beam of light on a face of the support, in which device the light source is configured so that the emission surface has a longitudinally extending axis, in which device the light guide comprises at least one emitting portion configured to emit light out of the guide, and at least one guide portion, situated between the source and the emitting portion, configured to transmit the beam of light from the source to the emitting portion, wherein the guide portion has a cross section that is smaller than that of the emitting portion.
By using such light sources, also referred to as multi-point sources, the light emitters are incorporated into the source and a beam of light is available that has a higher intensity of brightness while at the same time the difficulties of incorporating the light sources into the device are limited. Specifically, for a given intensity of light emitted by the device, the sources are less numerous than is the case if using single-point sources. In other words, such a solution makes it easier for the light sources and the guide to be coupled together.
According to various embodiments of the invention, which may be considered together or separately:
The invention also relates to a lighting and/or signaling housing comprising the device.
These and other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
The invention will be better understood in the light of the following description which is given purely by way of nonlimiting indication, and which is accompanied by the attached drawings in which:
As illustrated in
The device comprises at least one light source 1 and a light guide 2.
As is more visible in
The support 4 is, for example, a printed circuit. It is used notably for attaching the light emitting components 6 and/or for supplying them with electrical current. It may be a support of SMI type or an insulated metal substrate. Optionally, the support 4 further comprises components for controlling the strength of current supplied to the light emitting components 6.
The light emitting components 6 are, for example, light emitting diodes. They advantageously emit a white light, because white diodes are currently the most powerful.
The light emitting components 6, in this instance the light emitting diodes, are arranged in such a way as to define an emission surface 10 for the beam of light on one face 12 of the support 4. In other words, the light emitting components are arranged on one and the same side of the support 4, in a dedicated zone thereof. That being the case, the beam emitted by the emission surface 10 has a light intensity which is not necessarily completely homogeneous. In particular, the emission surface may have zones that light up better than others. The light emitting components 6 are, however, packed closely enough within the emission surface 10 to avoid giving the impression of there being any unlit zones between them. The light source 2 may be configured in such a way that the emission surface 10 has a longitudinal axis of extension. In other words, the emission surface 10 has a favored direction of elongation. Put differently again, the emission surface is neither square nor circular. In this instance it is substantially rectangular.
If reference is made once again to
The light guide 2 is configured to guide the light that enters via the inlet faces 14 as far as an outlet face 16 of the guide 2, notably using total internal reflection. In the known way, the guide 2 comprises a reflection face 18, equipped with optical patterns which have not been illustrated that allow some of the rays of light traveling along the guide 2 to emerge therefrom via the outlet face 16, provided opposite the reflection face 18.
The light guide 2 in this instance is a linear guide, of straight or curved longitudinal shape, depending on the usage requirements for the device 1. In other words, the guide 2 takes the form of a string or longilinear element, i.e. an element which has a cross section the dimensions of which are very much smaller than its length. Devices equipped with such guides 2 are particularly advantageous because they can be laid out in numerous ways, in a minimum amount of space. It is thus possible to give the guides 2 original shapes and allow esthetic creations of innovative design.
The light guide 2 here comprises at least one emitting portion 20 configured to emit light out of the guide 2, and at least one guide portion 22, situated between the source 1 and the emitting portion 20, and configured to transmit the beam of light from the source 1 to the emitting portion 20. In other words, the inlet faces 12 of the guide 2 are at the guide portions 22, whereas the reflection faces 18 and outlet faces 16 are at the emitting portion 20. The emitting portion 20 has, for example, a circular and/or constant cross section, if the optical patterns created are disregarded.
According to the embodiment of
According to the other embodiments illustrated, the device comprises several the light sources 1 and the light guide 2 comprises several guide portions 22 which are situated between each of the sources 1 and the emitting portion 20. Here, two light sources 1 and two guide portions 22, respectively associated with one another, are provided.
The guide portions 22 advantageously have a transverse axis of elongation oriented along the longitudinal axis of the emission surface 10 of the light sources 1. In other words, the guide portions 22 are likewise elongate in a given direction and their direction of elongation is made to correspond to that of the corresponding light sources 1 emission surface. To this end, the cross section of the guide portions 22 is, for example, rectangular, as in
If reference is made to
In this variant, the guide 2 comprises an interface zone 24 forming an interface between the guide portions 22, and defined by a plane. In other words, the guide 2 has a zone of convergence situated upstream of the emitting portion 20. The plane 28 is, for example, perpendicular to the inlet face 26 of the emitting portion 22. The guide portions are advantageously symmetric on either side of the plane in the convergence zone. The guide portions 22 are here, for example, of circular and/or constant cross section, before the convergence zone. The coupling portion 32 formed by the union of the guide portions 22 in the convergence zone may also be of constant cross section as far as the inlet face 26 of the emitting portion 20, i.e., may be of a cross section similar to the profile of the interface zone 28.
The latter may have a shape that exhibits symmetry with respect to an axis of symmetry of the inlet face 26 of the emitting portion 20, notably one of the diameters thereof.
In a first configuration, the guide portions 22 converge to a single point at the surface of the inlet face 26 of the emitting portion 20, notably the center thereof. In another configuration, they converge to two distinct points on the inlet face 26 of the emitting portion 20, for example points approximately 2 mm apart.
As an alternative, according to the embodiments of
The interface zones 30 could be symmetric with respect to one another about an axis of symmetry of the inlet face 26 of the emitting portion 20, notably one of the diameters thereof.
In other words, in these various embodiments, the interface zones 24, 30 can be considered to be centered on the inlet face 26 of the emitting portion 2. Such a feature likewise contributes to reducing optical losses.
Advantageously, each of the guide portions 22 will have a cross section that is smaller than that of the emitting portion 20. More specifically, in this case, the surface area of the interface zone 24, in the embodiment of
In the embodiments of
The invention also relates to a lighting and/or signaling housing comprising one or more devices as described above. The housing may comprise other types of lighting and/or signaling devices so as to combine a number of optical functions.
While the system, apparatus, process and method herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise system, apparatus, process and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1261511 | Nov 2012 | FR | national |
