Optical unit with photon scattering not perpendicular to the light guide input

Abstract

The present invention relates to an optical unit for a vehicle, comprising a housing delimiting a cavity in which are arranged an electronic board (130) comprising at least one photon source (710, 720) and at least one light guide (100); each light guide (100) being configured so that an input face is illuminated by at least one photon source; a longitudinal axis (610) of each light guide being non-perpendicular to the electronic board; the input face of each light guide having a first (810), a second (820) and a third (830) facet; the first and second facets of each light guide being perpendicular to the longitudinal axis (610) of a light guide and offset from each other; and the third facet (830) of a light guide connecting the first and second facets (810, 820).

Description

[0001] DESCRIPTION

[0002] Title: Optical block with photon diffusion not perpendicular to the light guide entrance

[0003] The present invention claims priority from French application 2208611 filed on 08 / 29 / 2022, the content of which (text, drawings and claims) is incorporated herein by reference.

[0004] Technical field

[0005] The present invention relates to optical units which equip vehicles, for example of the automobile type, to ensure at least one photometric signaling or lighting function. The invention relates in particular to an optical unit comprising at least one light guide and an electronic card carrying at least one photon source.

[0006] Technological background

[0007] Some optical units (also called projectors or headlights) are intended to equip vehicles (for example, of the automobile type). These optical units comprise a housing delimiting a cavity in which certain elements are arranged, including an electronic card carrying at least one photon source and at least one light guide cooperating together to provide at least one photometric signaling and / or lighting function. The light guide comprises an entry face capable of propagating photons emitted by the photon source in the light guide. A translucent screen may also be coupled to the housing to close the cavity.

[0008] Some optical blocks include several parallel light guides and several photon sources can be arranged to illuminate each of these light guides.

[0009] For economic reasons, it is common for the different light guides of an optical block to form a single plastic block in order to have a single part to inject and also to position all the photon sources on the same electronic card (PCB), that is to say on the same plane.

[0010] Figure 1 illustrates an example of composition of three light guides 100, 110, 120 and an electronic card 130 carrying photon sources (not shown). The light guides 100, 110 and 120 have dimensions and a radius of curvature which allow them to be housed in the cavity and which are adapted to convey the photons emitted by the photon sources to a desired zone referenced here 140. The input face of each light guide, for example the input face 101 of the light guide 100 (figure 2), is parallel to the electronic card 130, that is to say parallel to a plane P carried by the electronic card 130. One or more photon beams then propagate and mix in each light guide 100, 110 and 120 by bouncing off the walls of the light guide (represented by dotted lines). These photons then strike a prism 102 which returns the photon beams in a desired direction.

[0011] Such a solution makes it possible to propagate one or more photon beams from one or more photon sources positioned on the electronic card 130 to the desired area 140.

[0012] However, such a solution is difficult to implement because of the dimensional constraints which are generally limited for the optical block and therefore for the housing. Indeed, depending on the location of the electronic card 130 in the cavity and the desired zone 140, it may happen that the dimensions and the curvature of the light guides 100, 110 and 120 require a relatively large depth Pr of housing which implies a bulky optical block whereas compact optical blocks are very often sought.

[0013] Furthermore, the positioning of the electronic card 130 is also constrained to be inside the cavity. Usually positioned on the top of the optical block, the electronic card is constrained by the upper edge of the cavity. Figure 3 illustrates an example of impossible positioning of the electronic card 130 in a housing 1 because the electronic card 130 leaves the volume of the housing 1, that is to say that a dimension here referenced Le exceeds an upper limit L of the housing 1.

[0014] Another solution for arranging the electronic card 130 and light guides 100, 110 and 120 is to associate an electronic card 130i, respectively 1302 and 1303 with each light guide 100, respectively 110 and 120, but the size still remains significant and such an arrangement requires relatively large optical blocks. In addition, such an arrangement increases the manufacturing price compared to an arrangement using only a single electronic card. Furthermore, this arrangement requires the addition of connections 400 between electronic cards 130i, 1302 and 1303 as illustrated in FIG. 4.

[0015] The most compact and economical arrangement to manufacture is therefore to position a single electronic card at the upper limit of the cavity and to arrange the light guides opposite the photon sources carried by this electronic card.

[0016] The shape of the cavity usually requires that the longitudinal axis of a proximal straight portion located at an entrance of the guide and delimited at its end by the photon entry face 610, called longitudinal axis 610, of the light guides 100, 110 and 120 are not perpendicular to the electronic card 130 and therefore to the photon sources.

[0017] However, it appears that this arrangement is not suitable for optimal propagation of photon beams through these light guides.

[0018] Indeed, when the light guides are positioned so that their input faces are parallel to the electronic card 130 and the input face of each light guide is not perpendicular to the longitudinal axis 610 of this light guide (figure 5), the photons, emitted by one or more photon sources enter each light guide, for example the light guide 100, and are reflected on the face of the light guide facing the photon sources. This results in a poorly lit area 600 in the light guide 100 which will be poorly perceived by an external observer because it is heterogeneous.When the light guides are positioned so that their input faces are not parallel to the electronic card 130 but that these input faces are perpendicular to the longitudinal axis 610 of the light guide 100 as illustrated in FIG. 6, the photons emitted by a first photon source 710 enter the light guide 100 and propagate correctly along the light guide 100 by reflection on its faces. On the other hand, when a photon source 720 is further away from one of the input faces of the light guide 100, only a portion of the photons emitted by this photon source 720 enter the light guide 100. In addition, the problem of poorly lit area 600 is still present in this arrangement.

[0019] The arrangements in figures 5 and 6 between the light guide and the electronic card are not satisfactory and need to be improved to eliminate, among other things, the poorly lit areas in the light guides.

[0020] Summary of the present invention

[0021] One of the objects of the present invention is to solve at least one of the problems or deficiencies of the technological background described above.

[0022] Another object of the present invention is to propose a compact optical unit effectively ensuring at least one photometric signaling and / or lighting function.

[0023] According to a first aspect, the present invention relates to an optical unit intended to equip a vehicle and comprising a housing delimiting a cavity in which an electronic card is arranged comprising at least one photon source and at least one light guide;

[0024] - each light guide being configured so that an input face of each light guide is illuminated by at least one photon source;

[0025] - a longitudinal axis of a proximal straight portion located at an entrance of the guide and delimited at its end by the photon entry face, called the longitudinal axis, of each light guide being non-perpendicular to a plane carried by the electronic card; - the entry face of each light guide having a first, a second and a third facet;

[0026] - the first and second facets of each light guide being perpendicular to the longitudinal axis of a light guide and offset from each other along said longitudinal axis and the third facet of a light guide joining the first and second facets of said light guide.

[0027] The arrangement of the first, second and third facets of a light guide according to the invention allows good diffusion of photons by optical refraction along the light guide.

[0028] In addition, the arrangement of the first, second and third facets of a light guide according to the present invention makes it possible to diffuse all of the photon beams emitted by several light sources dedicated to this light guide.

[0029] The invention makes it possible to significantly reduce the volume required to house the electronic card and the light guide(s), thus increasing the compactness of the optical unit and facilitating various styles of optical units.

[0030] The optical unit according to the invention may include other characteristics which may be taken separately or in combination, in particular among the following embodiments.

[0031] According to a variant, one end of the first facet and one end of the second facet of at least one light guide belong to the same plane parallel to said plane carried by the electronic card.

[0032] According to a variant, the third facet of a light guide is perpendicular to the first and second facets of said light guide.

[0033] According to one variant, the electronic card includes several photon sources.

[0034] According to a variant, at least the first, second or third facet of at least one light guide is illuminated by several photon sources.

[0035] According to one embodiment, several photon sources illuminate each of the first and second facets of at least one light guide. According to one embodiment, a photon source is a light-emitting diode or a laser diode or a light bulb.

[0036] According to a second aspect, the present invention relates to a vehicle, for example of the automobile type or of the land motor vehicle type, comprising one (or at least one) optical unit according to the first aspect of the present invention.

[0037] Brief description of the figures

[0038] Other characteristics and advantages of the present invention will emerge from the description of the particular and non-limiting exemplary embodiments of the present invention below, with reference to the appended figures 1 to 10, in which:

[0039] [Fig. 1] illustrates an example of the composition of three light guides and an electronic card carrying photon sources according to the state of the art;

[0040] [Fig. 2] illustrates an example of curvature of a light guide and its positioning relative to an electronic card according to the state of the art;

[0041] [Fig. 3] illustrates an example of impossible positioning of an electronic card in a cavity formed by a housing of an optical block;

[0042] [Fig. 4] illustrates an example of an arrangement of multiple electronic boards and multiple light guides;

[0043] [Fig. 5] illustrates a defect in a light guide arrangement relative to a state-of-the-art electronic card;

[0044] [Fig. 6] illustrates a defect in a light guide arrangement relative to a state-of-the-art electronic card;

[0045] [Fig. 7] schematically illustrates an example of an optical block housing;

[0046] [Fig. 8] illustrates an arrangement of an electronic card and a light guide according to a particular and non-limiting example of the present invention; [Fig. 9] illustrates a three-dimensional view of an arrangement of two light sources and a light guide according to a particular and non-limiting example of the present invention; and

[0047] [Fig. 10] illustrates a variation of the arrangement of Figure 11;

[0048] Description of examples of implementation

[0049] An optical unit intended to equip a vehicle will now be described in the following with joint reference to figures 1 to 10. Unless otherwise indicated, elements common or similar to several figures bear the same reference signs and have identical or similar characteristics, so that these common elements are generally not described again for the sake of simplicity.

[0050] The terms "first(s)", "second(s)", etc.) are used in this document by arbitrary convention to enable the identification and distinction of different elements (such as faces, facets, operations, threshold values, etc.) implemented in the exemplary embodiments described below.

[0051] In this document, the term "optical unit" means a lighting device (or light device) providing at least one photometric lighting and / or signaling function. This may include, in particular, a headlight or front projector or a front or rear light.

[0052] The present invention relates to an optical unit intended to equip a vehicle, such as a vehicle of the automobile or other type, or more generally a vehicle of the motorized land vehicle type or any vehicle (land, sea (or river), or air) as soon as it must comprise at least one optical unit.

[0053] As already indicated, the present invention aims at a compact optical block efficiently performing at least one photometric signaling and / or lighting function. To do this, a particular combination of facets at the entrance of each light guide of the optical block is produced in combination with an electronic card comprising at least one photon source to supply light to the light guide(s).

[0054] According to a particular and non-limiting example of embodiment of the present invention, this optical unit, intended to equip a vehicle and a housing delimiting a cavity in which an electronic card comprising at least one photon source and at least one light guide are arranged;

[0055] - each light guide being configured so that an input face of each light guide is illuminated by at least one photon source;

[0056] - a longitudinal axis of a proximal straight portion located at an entrance of the guide and delimited at its end by the photon entry face, called the longitudinal axis, of each light guide being non-perpendicular to a plane carried by the electronic card;

[0057] - the entrance of each light guide having a first, a second and a third facet;

[0058] - the first and second facets of each light guide being perpendicular to the longitudinal axis of a light guide and offset from each other along said longitudinal axis and the third facet of a light guide joining the first and second facets of said light guide.

[0059] Figures 1 to 10 schematically illustrate certain elements of an optical unit before the installation of this optical unit in a vehicle, according to a particular non-limiting example of embodiment and various variant embodiments. It is considered subsequently, by way of non-limiting example, that the optical unit is intended to equip a motor vehicle (not shown), but the present invention is not limited to this application. The optical unit can in fact equip any vehicle, of the automobile type or of the motorized land vehicle type (bus, coach, truck, etc.), having to provide at least one photometric lighting and / or signaling function.

[0060] Furthermore, it is considered in the following, by way of non-limiting example, that the optical unit is a front headlight (or front projector). For example, this front headlight can equip part of a front tailgate and / or a front wing of a vehicle. But the optical unit could also be a rear light. In addition, it is considered subsequently that the optical unit comprises three light guides but the present invention is not limited to this number of light guides and the optical unit can comprise one or more light guides.

[0061] Figures 7 to 10 illustrate different aspects of certain elements of the optical unit, different embodiments implementing certain of these aspects being described subsequently with reference to the figures.

[0062] As illustrated in Figure 7, an optical block comprises a housing 1 delimiting a cavity 10 in which an electronic card 130 is arranged comprising at least one photon source (not shown) and at least one light guide 100, 110 and 120. Each light guide 100, 110 and 120 is configured so that an input face of each light guide is illuminated by at least one photon source.

[0063] More specifically, the housing 1 can be produced for example by molding an opaque and rigid material, such as a plastic or synthetic material. The housing 1 delimits the cavity 10 housing the elements 100, 110, 120 and 130 participating together in the production of at least one photometric lighting and / or signaling function.

[0064] The electronic card 130 comprises at least one photon source for supplying light to at least one light guide (110, 120, 130). Each photon source may, for example, comprise at least one light-emitting diode (or LED) or at least one laser diode or at least one bulb. The configuration of the photon source(s) in terms of number, positioning, arrangement, type, etc. may be adapted by a person skilled in the art as appropriate. The electronic card 130 comprises electronic means configured to control the operation of each photon source. This card may, for example, be a printed circuit board of the PCB type (for "Printed Circuit Board" in English). The electronic card 130 is carried by a plane P, that is to say that all of the photon sources are carried by this plane P.

[0065] Each light guide (100, 110, 120) is configured to be supplied with light (in photons) by the photon source(s) of the electronic card 130, and to guide this light towards the front of the optical block in order to ensure the desired photometric function(s). Each light guide (100, 110, 120) comprises a plurality of planar members which can extend inclined towards the front of the optical block, other arrangements being however possible in terms in particular of numbers, positions, orientations, etc. of the planar members. The number of planar members can in particular take any value greater than or equal to one (1), and in particular, one, two, three or four. The planar members can all extend in the same direction or in different directions as the case may be.

[0066] The planar (or flat) members are configured to guide the light provided by the photon source(s) of the electronic card 130. These planar members may have different shapes, in particular rectangular, square or round, provided that these members are flat or have at least one planar surface. In this respect, each planar member comprises, for example, two parallel planar surfaces. The planar members form, for example, light-guiding blades.

[0067] The optical block may further comprise a translucent glass assembled to the housing 1 to close the cavity 10. This glass (or screen) may be made of any translucent material, having a color adapted to the desired photometric function (for example red, orange, crystal, etc.), and rigid, such as for example a plastic or synthetic material. In this case, it may be made by molding.

[0068] Figure 8 illustrates an arrangement of the electronic card 130 and a light guide 100 according to a particular and non-limiting example of the present invention.

[0069] According to this arrangement, the longitudinal axis of each light guide (100, 110, 120) is non-perpendicular to the electronic card 130. The entrance of each light guide (100, 110, 120) has three planar members called first facet 810, second facet 820 and a third facet 830. The first facet 810 and the second facet 820 of each light guide (100, 110, 120) are perpendicular to the longitudinal axis 610 of a light guide (100, 110, 120) and the first and second facets are offset from each other along said longitudinal axis 610. The third facet of the light guide joining the first and second facets of the light guide (100, 110, 120).The different refractions on the first, second and third facets allow the guides to be illuminated as early as possible, thus eliminating the appearance of unlit areas such as those occurring for other arrangements presented in the introduction to this application.

[0070] Figure 9 illustrates a three-dimensional view of an arrangement of two light sources and a light guide according to the particular and non-limiting exemplary embodiment of the present invention of Figure 8.

[0071] According to a variant, illustrated in figure 8, one end of the first facet 810 and one end of the second facet 820 of at least one light guide (100, 110, 120) belong to the same plane 840 parallel to the plane P carried by the electronic card 130.

[0072] According to a variant, the third facet 830 of a light guide is perpendicular to the first 810 and to the second 820 facet of said light guide.

[0073] According to one variant, the electronic card 130 comprises several photon sources.

[0074] According to a variant, at least the first, second or third facet of at least one light guide is supplied with light by several photon sources.

[0075] This variant allows the light output of the optical unit to be increased.

[0076] According to an exemplary embodiment of this variant, several photon sources are associated with each of the first and second facets of at least one light guide, in this case 2 per facet in figure 10.

[0077] The optical unit according to the present invention makes it possible to effectively ensure at least one photometric signaling and / or lighting function while being compact. The optical unit may in particular comprise one or more light guides with a so-called effect

[0078] "suspended" in the sense that they appear to be suspended from the point of view of an external observer. When the planar members project the photons emanating from the photon source(s) of the electronic card, the technical elements of the optical block (electronic card, connector, lower part of the light guide) are hidden, which makes it possible to achieve the desired visual effect while ensuring good assembly quality (precise and reliable positioning of the parts relative to each other, including while the vehicle is moving).

[0079] A person skilled in the art will understand that the exemplary embodiments and variants described above constitute only non-limiting examples of implementation of the invention. In particular, a person skilled in the art may envisage any adaptation or combination of the exemplary embodiments and variants described above, in order to meet a very specific need.

[0080] The present invention is therefore not limited to the exemplary embodiments described above but extends in particular to an optical unit which would include secondary characteristics without thereby departing from the scope of the present invention.

[0081] The present invention also relates to a vehicle, for example a motor vehicle or more generally a land motor vehicle, comprising at least one optical unit as described above.

Claims

CLAIMS 1. Optical unit intended to equip a vehicle and comprising a housing (1) delimiting a cavity (10) in which an electronic card (130) is arranged comprising at least one photon source (710, 720) and at least one light guide (100, 110, 120); - each light guide (100, 110, 120) being configured so that an input face of each light guide is illuminated by at least one photon source; - a longitudinal axis of a proximal straight portion located at an entrance of the guide and delimited at its end by the photon entry face (610), called longitudinal axis, of each light guide being non-perpendicular to a plane carried by the electronic card; - the entry face of each light guide having a first (810), a second (820) and a third (830) facets; - the first and second facets of each light guide being perpendicular to said longitudinal axis (610) of a light guide and offset from each other along said longitudinal axis and the third facet (830) of a light guide joining the first and second facets (810, 820) of said light guide.

2. Optical block according to claim 1, in which one end of the first facet and one end of the second facet of at least one light guide belong to the same plane parallel to said plane carried by the electronic card.

3. Optical unit according to claim 1 or 2, in which the third facet of a light guide is perpendicular to the first and second facet of said light guide.

4. Optical unit according to one of the preceding claims, in which the electronic card comprises several photon sources. Optical unit according to claim 4, wherein at least the first, second or third facet of at least one light guide is illuminated by several photon sources. Optical unit according to claim 4, wherein several photon sources illuminate each of the first and second facets of at least one light guide. Optical unit according to one of the preceding claims, wherein a photon source is a light-emitting diode or a laser diode or a bulb. Vehicle comprising at least one optical unit according to one of the preceding claims. Vehicle according to claim 8, wherein said vehicle is of the automobile type.

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