Light device with photon scattering not perpendicular to the entry surface of the light conductor

Description

[0001] The present invention claims priority from French application 2208611 filed on 29.08.2022. technical field

[0002] The present invention relates to optical units fitted to vehicles, for example automobiles, to provide at least one photometric function for signaling or lighting. The invention particularly relates to an optical unit comprising at least one light guide and an electronic circuit board carrying at least one photon source. Technological background

[0003] Some optical units (also called projectors or headlights) are designed for use on vehicles (e.g., automobiles). These optical units comprise a housing enclosing a cavity in which certain components are arranged, including an electronic circuit board containing at least one photon source and at least one light guide. These components work together to provide at least one photometric function for signaling and / or lighting. The light guide has an entrance face that allows photons emitted by the photon source to propagate through the light guide. A translucent screen may also be attached to the housing to close the cavity.

[0004] Some optical blocks include several parallel light guides and multiple photon sources can be arranged to illuminate each of these light guides.

[0005] 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 piece to be injected and also to position all the photon sources on the same electronic board (PCB), i.e. on the same plane.

[0006] There figure 1 illustrates an example of a composition of three light guides 100, 110, 120 and an electronic board 130 carrying photon sources (not shown). The light guides 100, 110 and 120 have dimensions and a radius of curvature that allow them to be housed in the cavity and are adapted to direct the photons emitted by the photon sources to a desired area, here referenced as 140. In this example, which falls outside the scope of the invention, the entrance face of each light guide, for example the entrance face 101 of the light guide 100 ( figure 2), is parallel to the electronic board 130, that is, parallel to a plane P carried by the electronic board 130. One or more beams of photons propagate and then mix in each light guide 100, 110, and 120 by bouncing off the walls of the light guide (represented by dashed lines). These photons then strike a prism 102, which reflects the photon beams in a desired direction.

[0007] Such a solution allows one or more photon beams from one or more photon sources positioned on the electronic board 130 to be propagated to the desired area 140. Document EP 3 176 495 A1 also presents this configuration in which the longitudinal axis of a proximal straight portion located at an entrance of the guide is perpendicular to the plane of the electronic board.

[0008] However, such a solution is difficult to implement due to the generally limited dimensional constraints of the optical block and therefore the housing. Indeed, depending on the location of the electronic board 130 within the cavity and the desired area 140, the dimensions and curvature of the light guides 100, 110, and 120 may require a relatively large housing depth Pr, which implies a bulky optical block, whereas compact optical blocks are very often preferred.

[0009] Furthermore, the positioning of the electronic board 130 is also constrained to being inside the cavity. Normally positioned on top of the optical block, the electronic board is constrained by the upper edge of the cavity.

[0010] There figure 3This illustrates an example of the impossibility of positioning the electronic board 130 within a housing 1 because the electronic board 130 extends beyond the volume of the housing 1; that is, a dimension here referenced as Lc exceeds an upper limit L of the housing 1. Another solution for arranging the electronic board 130 and the light guides 100, 110, and 120 is to associate an electronic board 1301, 1302, and 1303 respectively with each light guide 100, 110, and 120, but the overall size remains significant, and such an arrangement requires relatively large optical blocks. Furthermore, this arrangement increases the manufacturing cost compared to an arrangement using only a single electronic board. Furthermore, this arrangement requires the addition of 400 connections between electronic boards 1301, 1302 and 1303 as illustrated in the figure 4 .

[0011] The most compact and economical arrangement to manufacture is therefore to position a single electronic board at the upper limit of the cavity and to place the light guides opposite the photon sources carried by this electronic board.

[0012] The shape of the cavity usually dictates that the longitudinal axis of a proximal straight portion located at an entrance of the guide and delimited at its end by the photon entrance face 610, referred to as the longitudinal axis 610, of the light guides 100, 110, and 120, is not perpendicular to the electronic board 130 and therefore to the photon sources. However, it appears that this arrangement is not suitable for optimal propagation of photon beams through these light guides.

[0013] Indeed, when the light guides are positioned so that their entry faces are parallel to the electronic board 130 and the entry face of each light guide is not perpendicular to the longitudinal axis 610 of that light guide ( figure 5 (Example outside the scope of the invention), photons emitted by one or more photon sources enter each light guide, for example light guide 100, and are reflected off the face of the light guide facing the photon sources. This results in a dimly lit area 600 within light guide 100, which will be poorly perceived by an external observer due to its heterogeneity.

[0014] When the light guides are positioned so that their entrance faces are not parallel to the electronic board 130 but are perpendicular to the longitudinal axis 610 of the light guide 100 as illustrated in the figure 6In an example outside the scope of the invention, the photons emitted by a first photon source 710 enter the light guide 100 and propagate correctly along the light guide 100 by reflection off its faces. However, when a photon source 720 is further away from one of the entrance faces of the light guide 100, only a portion of the photons emitted by this photon source 720 enter the light guide 100. Furthermore, the problem of a dimly lit area 600 is still present in this arrangement.

[0015] The arrangements of figures 5 and 6 The relationship between the light guide and the electronic board is not satisfactory and needs to be improved to eliminate, among other things, the poorly lit areas in the light guides. Summary of the present invention

[0016] 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.

[0017] Another object of the present invention is to provide a compact optical block efficiently ensuring at least one photometric function of signaling and / or lighting.

[0018] According to a first aspect, the present invention relates to an optical block intended to equip a vehicle and comprising a housing delimiting a cavity in which are arranged an electronic card comprising at least one photon source and at least one light guide; each light guide being configured so that an entrance 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 entrance face, called the longitudinal axis, of each light guide being not perpendicular to a plane carried by the electronic board; the entrance face of each light guide having a first, a second and a third facet; the first and second facets of each light guide being perpendicular to the longitudinal axis of the light guide and offset from each other along said longitudinal axis and the third facet of the light guide joining the first and second facets of said light guide.

[0019] 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.

[0020] Furthermore, the arrangement of the first, second, and third facets of a light guide according to the present invention allows for the diffusion of all photon beams emitted by several light sources dedicated to this light guide. The invention significantly reduces the volume required to house the electronic board and the light guide(s), thus increasing the compactness of the optical block and facilitating a variety of optical block designs.

[0021] The optical block according to the invention may include other features which may be taken separately or in combination, in particular among the following embodiments.

[0022] According to one 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 board.

[0023] According to one variant, the third facet of a light guide is perpendicular to the first and second facets of said light guide.

[0024] In one variant, the electronic board includes several photon sources. In another variant, at least the first, second, or third facet of at least one light guide is illuminated by several photon sources.

[0025] According to one variant, several photon sources illuminate each of the first and second facets of at least one light guide.

[0026] According to one variant, a photon source is a light-emitting diode, a laser diode, or a light bulb.

[0027] 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. Brief description of the figures

[0028] Other features and advantages of the present invention will become apparent from the description of the specific and non-limiting embodiments of the present invention below, with reference to Figures 1 to 10 attached, in which: [ Fig. 1 ] illustrates an example of a composition of three light guides and an electronic board carrying photon sources according to the state of the art; [ Fig. 2 ] illustrates an example of the curvature of a light guide and its positioning relative to an electronic board according to the state of the art; [ Fig. 3] illustrates an example of the impossible positioning of an electronic board in a cavity formed by the housing of an optical block; [ Fig. 4 ] illustrates an example of the arrangement of multiple electronic boards and multiple light guides; [ Fig. 5 ] illustrates a defect in the arrangement of light guides compared to a state-of-the-art electronic board; [ Fig. 6 ] illustrates a defect in the arrangement of light guides compared to a state-of-the-art electronic board; [ Fig. 7 ] schematically illustrates an example of an optical block housing; [ Fig. 8 ] illustrates an arrangement of an electronic board 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 an embodiment outside the scope of the present invention; and [ Fig. 10 And 11] illustrate variations in the arrangement of the figure 8 ; Description of examples of achievements

[0029] An optical unit intended to equip a vehicle will now be described in what follows with joint reference to figures 1 to 11.

[0030] 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.

[0031] The terms "first(s)", "second(s)", etc.) are used in this document by arbitrary convention to allow identification and distinction of different elements (such as faces, facets, operations, threshold values, etc.) implemented in the embodiment examples described below.

[0032] In this document, the term "optical unit" refers to a lighting device (or luminous device providing at least one photometric function for lighting and / or signaling). This may include, in particular, a headlight or front projector, or a front or rear light.

[0033] The present invention relates to an optical unit intended to equip a vehicle, such as a motor vehicle or other type vehicle, or more generally a motorized land vehicle or any vehicle (land, sea (or river), or air) as soon as it must include at least one optical unit.

[0034] As already mentioned, the present invention relates to a compact optical block that efficiently performs at least one photometric function for signaling and / or lighting. To achieve this, a specific combination of facets at the entrance of each light guide of the optical block is implemented in conjunction with an electronic board comprising at least one photon source to supply light to the light guide(s).

[0035] Figures 1 to 11 schematically illustrate certain elements of an optical block before the installation of this optical block in a vehicle, according to embodiment examples, some of which fall outside the scope of the invention.

[0036] For the purposes of this discussion, we will consider, as a non-limiting example, that the optical unit is intended for use in a motor vehicle (not shown), but the present invention is not limited to this application. The optical unit can indeed be used in any type of vehicle, whether a motor vehicle or a motorized land vehicle (bus, coach, truck, etc.), that must perform at least a photometric function for lighting and / or signaling. Furthermore, for the purposes of this discussion, we will consider, as a non-limiting example, that the optical unit is a headlight (or front projector). For example, this headlight can be fitted to part of a front tailgate and / or a front fender of a vehicle. However, the optical unit could also be a taillight.

[0037] Furthermore, it is subsequently assumed that the optical block comprises three light guides, but the present invention is not limited to this number of light guides and the optical block may comprise one or more light guides.

[0038] THE figures 7, 8 , 10 And 11 illustrate different aspects of certain elements of the optical block, different examples of implementation implementing some of these aspects being described subsequently with reference to the figures.

[0039] As illustrated in the figure 7 , an optical block includes a housing 1 delimiting a cavity 10 in which are arranged an electronic board 130 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 one entrance face of each light guide is illuminated by at least one photon source.

[0040] More specifically, the housing 1 can be made, for example, by molding an opaque and rigid material, such as a plastic or synthetic material. The housing 1 defines the cavity 10 which houses the elements 100, 110, 120, and 130 that work together to perform at least one photometric function for lighting and / or signaling. The electronic board 130 includes at least one photon source to supply light to at least one light guide (110, 120, 130). Each photon source can, for example, include at least one light-emitting diode (LED), at least one laser diode, or at least one light bulb. The configuration of the photon source(s) in terms of number, positioning, arrangement, type, etc., can be adapted by a person skilled in the art as appropriate. The electronic board 130 includes electronic means configured to control the operation of each photon source.This card could, for example, be a printed circuit board (PCB). The electronic card 130 is located on a plane P, meaning that all the photon sources are located on this plane P.

[0041] Each light guide (100, 110, 120) is configured to be supplied with light (photons) by the photon source(s) of the electronic board 130, and to guide this light towards the front of the optical block in order to ensure the desired photometric function(s).

[0042] Each light guide (100, 110, 120) comprises a plurality of planar members that can extend at an angle toward the front of the optical block, although other arrangements are possible, particularly in terms of the number, position, orientation, etc., of the planar members. The number of planar members can be 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 appropriate.

[0043] The flat members are configured to guide the light supplied by the photon source(s) of the electronic board 130. These flat members can have various shapes, including rectangular, square, or round, as long as they are flat or have at least one flat surface. For example, each flat member might have two parallel flat surfaces. The flat members form, for instance, blades that guide the light.

[0044] The optical block may further include a translucent lens assembled to the housing 1 to close the cavity 10. This lens (or screen) may be made of any translucent material, having a color suitable for the desired photometric function (for example, red, orange, crystal, etc.), and rigid, such as a plastic or synthetic material. In this case, it may be made by molding.

[0045] There figure 8illustrates an arrangement of the electronic board 130 and a light guide 100 according to a particular and non-limiting example of the present invention.

[0046] According to this arrangement, the longitudinal axis of each light guide (100, 110, 120) is not perpendicular to the electronic board 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 joins the first and second facets of the light guide (100, 110, 120).

[0047] 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 occur for other arrangements presented in the introduction to this application.

[0048] There Figure 10 illustrates a three-dimensional view of an arrangement of two light sources and a light guide according to the particular and non-limiting embodiment of the present invention of the figure 8 .

[0049] According to one variant, illustrated in the 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.

[0050] According to one variant, the third facet 830 of a light guide is perpendicular to the first 810 and second 820 facet of said light guide.

[0051] In one variant, the electronic board 130 includes several photon sources. In another variant, at least the first, second, or third facet of at least one light guide is supplied with light by several photon sources.

[0052] This variant allows for an increase in the luminous power of the optical block.

[0053] According to one 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 on the figure 11 .

[0054] The optical unit according to the present invention effectively performs at least one photometric function for signaling and / or lighting while remaining compact. In particular, the optical unit may include one or more light guides with a so-called "suspended" effect, in the sense that they appear to be suspended from the perspective of an external observer. When the flat elements project the photons emanating from the photon source(s) of the electronic board, the technical components of the optical unit (electronic board, connector, lower part of the light guide) are concealed, thus achieving the desired visual effect while ensuring high-quality assembly (precise and reliable positioning of the parts relative to each other, even while the vehicle is in motion).

[0055] A person skilled in the art will understand that the embodiments and variations described above are merely non-limiting examples of how the invention can be implemented. In particular, a person skilled in the art may consider any adaptation or combination of the embodiments and variations described above to meet a specific need.

[0056] The present invention is therefore not limited to the embodiments described above but extends in particular to an optical block which would include secondary features defined in the following set of claims.

[0057] 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

1. Optical unit intended to be fitted to a vehicle and comprising a housing (1) defining a cavity (10) in which are arranged an electronic card (130) 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 entry face of each light guide is illuminated by at least one photon source (710, 720); - a longitudinal axis (610) of a proximal straight portion located at one entry of the guide and delimited at its end by the entry face of the photons, referred to as the longitudinal axis (610) of each light guide being non-perpendicular to each light guide to a drawing carried by the electronic board (130); - the entry face of each light guide having a first (810), a second (820) and a third (830) facets; - the first and the second facets of each light guide being perpendicular to said longitudinal axis (610) of the light guide and offset from one another by report along said longitudinal axis and the third facet (830) of the light guide joining the first and the second facets (810, 820) of the light guide joining the first and the second facets (810, 820) of said light guide.

2. Optical unit according to claim 1, wherein 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 a same drawing parallel to said drawing carried by the electronic card (130).

3. Optical unit according to claim 1 or 2, wherein the third facet (830) of a light guide (100, 110, 120) is perpendicular to the first facet (810) and to the second facet (820) of said light guide (100, 110, 120).

4. Optical unit according to claim 1, wherein the electronic card (130) comprises several photon sources (710, 720).

5. Optical unit according to claim 4, wherein at least the first (810), second (820) or third facet (830) of at least one light guide (100, 110, 120) is illuminated by several photon sources (710, 720).

6. Optical unit according to claim 4, wherein a plurality of photon sources (710, 720) illuminate each of the first (810) and second (820) facets of at least one light guide (100, 110, 120).

7. Optical unit according to claim 1, wherein a photon source (710, 720) is a light-emitting diode or a laser diode or a light bulb.

8. Vehicle comprising at least one optical unit according to one of the previous claims.

9. Vehicle according to claim 8, wherein said vehicle is of the motor vehicle type.