Double light guide involving end optical coupling

Abstract

The present invention relates to a system comprising two light guides (12, 13) that are coupled by an optical coupling means (14) intended to redirect photons arriving from a first cylindrical light guide (12) to a second cylindrical light guide (13); an opaque mask comprising windows (16, 17) through which parts of the first and / or second cylindrical light guide are visible; and a light return means positioned at each part of a cylindrical light guide (12, 13) that corresponds to a window in the mask.

Description

[0001] DESCRIPTION

[0002] Title: Double light guide by optical end coupling

[0003] Technical field

[0004] The present invention claims priority from French application 2208481 filed on 08 / 24 / 2022, the content of which (text, drawings and claims) is incorporated herein by reference. The present invention relates to headlights or lights which equip vehicles, for example of the automobile type, to provide a lighting and / or visual signaling function.

[0005] Technological background

[0006] Vehicles are equipped with lighting systems that are dedicated to visual signaling of the vehicle, such as, for example, front or rear lights or daytime running lights, also called daytime running lights ("Daytime running lamp" or "daytime running light" in English).

[0007] In this type of lighting systems, it is common to use "light guide" type optical systems.

[0008] Figure 1 schematically illustrates a light guide.

[0009] The light guide is usually presented as a cylindrical tube A comprising two ends. At one of these ends, a photon source B is positioned. This photon source B is intended to produce photons which propagate along the cylindrical tube A to light return means C positioned on one of the sides of the cylindrical tube A either over its entire length or only partially. These light return means C are very often prisms whose function is to modify the trajectories of the photos which are then redirected towards a desired direction typically transversely to the axis of the light guide A. It is known to use style masks which define the visual appearance of a luminous object.Usually, a style mask is opaque except in some of its parts, called windows, through which light beams emerge from photons propagating along a cylindrical light guide positioned behind the style mask. If the desired style mask is to obtain windows whose dimension is, for example, twice as large as the diameter of the cylindrical light guide, one can consider using a light guide of larger diameter. But the dimensions of the windows may not be constant and it is then financially expensive to use light guides of large diameter to illuminate only a few windows whose dimension would be equal to the diameter of this light guide.

[0010] Another alternative is to use a first light guide of small diameter to illuminate certain windows of the style mask and to superimpose a second light guide (or more) of small diameter to illuminate windows of a larger dimension.

[0011] The superposition of two or even more light guides limits the possibilities of the style mask while it is desired to give maximum freedom to create these style masks.

[0012] The problem is to define a lighting system that leaves maximum freedom for the creation of stylish masks.

[0013] Summary of the present invention

[0014] 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.

[0015] Another object of the present invention is to obtain a lighting system intended to equip a vehicle which produces homogeneous lighting while using a limited number of light guides.

[0016] Another object of the present invention is to obtain a lighting system which allows great freedom of design of windows of a style mask. The present invention consists in creating a coupling between them of the light guides two by two at one of their ends by an optical coupling means intended to redirect the photons arriving at the end of a first light guide towards the end of a second light guide so as to be able to illuminate windows of different dimensions of a style mask.

[0017] The present invention is particularly advantageous because it allows for much more varied mask styles than those currently found. Indeed, thanks to the optical coupling means, two light guides can be coupled at variable angles, which is not possible to achieve using a single light guide, due to the limitations of its radius of curvature, or by superimposing light guides.

[0018] The present invention is also advantageous because it uses only one photon source and not one photon source per light guide.

[0019] In addition, the manufacturing cost by plastic injection is reduced because only one injection is necessary to produce the different coupled guides.

[0020] According to a first aspect, the present invention relates to a lighting system intended to equip a vehicle, comprising

[0021] - a photon source;

[0022] - a first cylindrical light guide comprising a first end intended to be illuminated by the photon source;

[0023] - a second cylindrical light guide comprising a first end coupled to a second end of the first light guide by an optical coupling means intended to redirect the photons arriving at the second end of the first cylindrical light guide towards the first end of the second cylindrical light guide;

[0024] - an opaque mask comprising windows through which parts of the first and / or second cylindrical light guide are visible;

[0025] - a light return means being positioned at each part of the first and / or second cylindrical light guide corresponding to a window of the style mask so that photons propagating along the first and / or second cylindrical light guides are redirected towards said window.

[0026] According to one variant, the optical coupling means and the first end of the second cylindrical light guide are masked.

[0027] According to a variant, at least one of said windows is provided with optics or billiards.

[0028] According to a variant, a second end of the second cylindrical light guide is obstructed.

[0029] According to an exemplary embodiment, the first and second cylindrical light guides are longitudinally superimposed on each other at least on one of their parts; the optical coupling means is adapted to redirect the photons at an angle of 180 degrees; at least one of said windows, called the first window, has one of its dimensions which is less than a sum of the diameters of the first and second cylindrical light guides; and at least one of said windows, called the second window, has one of its dimensions which is at least equal to the sum of the diameters of the first and second cylindrical light guides.

[0030] According to a variant of this exemplary embodiment, the optical coupling means comprises a prism comprising two light-reflecting faces inclined at 45 degrees.

[0031] According to a variant of this exemplary embodiment, the second end of the second cylindrical light guide is mechanically connected to the first light guide.

[0032] According to an exemplary embodiment, the optical coupling means comprises a light-reflecting face inclined at an angle less than or equal to 90 degrees.

[0033] According to a variant, the lighting system further comprises a third light guide comprising a first end coupled to the second end of the second light guide by another optical coupling means.

[0034] 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 at least one lighting system according to the first aspect of the present invention. Brief description of the figures

[0035] 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 9, in which:

[0036] [Fig. 1] schematically illustrates a light guide.

[0037] [Fig. 2] schematically illustrates a lighting system according to an exemplary embodiment of the present invention;

[0038] [Fig. 3] schematically illustrates a coupling of two light guides according to an exemplary embodiment of the present invention;

[0039] [Fig. 4] schematically illustrates a means for reflecting light along a light guide according to an exemplary embodiment of the present invention;

[0040] [Fig. 5] schematically illustrates a means of optical coupling between two light guides according to an exemplary embodiment of the present invention;

[0041] [Fig. 6] schematically illustrates optical coupling constraints between two light guides according to an exemplary embodiment of the present invention;

[0042] [Fig. 7] schematically illustrates according to a variant of coupling of two light guides an exemplary embodiment of the present invention;

[0043] [Fig. 8] schematically illustrates according to a variant of coupling of two light guides an exemplary embodiment of the present invention;

[0044] [Fig. 9] schematically illustrates a variant of coupling two light guides, an exemplary embodiment of the present invention.

[0045] Description of examples of implementation

[0046] A lighting system intended to equip a vehicle will now be described in the following with reference to Figures 2-9. 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.

[0047] Figures 2-9 schematically illustrate a lighting system according to a particular non-limiting exemplary embodiment and various variant embodiments. It is considered below, by way of non-limiting example, that the lighting system is intended to equip a motor vehicle, but the present invention is not limited to this application. The lighting system can in fact equip any vehicle, of the automobile type or of the motorized land vehicle type (bus, coach, truck, etc.), which must provide at least one photometric lighting and / or signaling function.

[0048] Furthermore, it is subsequently considered that the lighting system comprises two or even three light guides, but the present invention is not limited to these numbers of light guides. The present invention extends to any lighting system which would comprise more than three light guides coupled two by two as well as to coupling means which redirect photons at any angle.

[0049] Figures 2-9 illustrate different aspects of the lighting system, different exemplary embodiments implementing some of these aspects being described subsequently with reference to the figures.

[0050] Figure 2 schematically illustrates a lighting system 1 according to an exemplary embodiment of the present invention.

[0051] System 1 includes a style 2 mask. The style 2 mask is opaque and formed, for example, from plastic material.

[0052] Mask 2 is opaque except in some of its parts 16 and 17, called windows, through which parts of light guides are visible, i.e. beams of light come out of these windows. These beams of light come from photons propagating along these light guides positioned behind the style mask 2.

[0053] According to an exemplary embodiment, at least one of the windows of the style 2 mask is provided with a translucent material, preferably having optics / beads for example made of opaline material, in order to blur the or each cylindrical light guide visible through said at least one window.

[0054] The lighting system 1 comprises a photon source 11, a first cylindrical light guide 12, a second cylindrical light guide 13 and a first optical coupling means 14.

[0055] The first cylindrical light guide 12 comprises a first end intended to be illuminated by the photon source 11. The second cylindrical light guide 13 comprises a first end coupled to a second end of the first cylindrical light guide 12 by an optical coupling means 14 intended to redirect the photons arriving at the second end of the first cylindrical light guide 12 towards the first end of the second cylindrical light guide 13.

[0056] According to a variant, the optical coupling means 14 and the first end of the second cylindrical light guide 13 are masked to obtain homogeneous lighting.

[0057] According to a variant, the second end of the second cylindrical light guide 13 is obstructed.

[0058] The lighting system 1 also comprises a light return means 18 (figure 4) positioned at each part of the first 12 and / or second 13 cylindrical light guides corresponding to a window of the style mask 2 so that photons propagating along the first or second cylindrical light guides are redirected towards said window in a desired direction.

[0059] For example, the optical light return means 18 transversely redirects the photons propagating longitudinally along a light guide.

[0060] Figure 3 schematically illustrates a coupling of two light guides according to an exemplary embodiment of the present invention.

[0061] The first 12 and second 13 cylindrical light guides are longitudinally superimposed on each other at least on one of their parts. The optical coupling means 14 is adapted to redirect the photons arriving at the end of the first cylindrical light guide 12 at an angle of 180 degrees so that they propagate along the second cylindrical light guide 13. At least one of the windows of the style mark 2, called first window 16, has one of its dimensions which is less than the sum of the diameters of the first 12 and 13 second cylindrical light guides and at least one of said windows, called second window 17, has one of its dimensions which is at least equal to the sum of the diameters of the first 12 and second 13 cylindrical light guides.

[0062] According to the example of Figure 3, the style mask 2 comprises three first windows 16 making visible three parts of the first cylindrical light guide 12 making visible parts of the first light guide 12, and a second window 17 making visible a part of the first cylindrical light guide 12 and a part of the second cylindrical light guide 13.

[0063] According to a variant of the exemplary embodiment of Figure 3, illustrated in Figure 5, the optical coupling means 14 comprises a prism comprising two light-reflecting faces inclined at 45 degrees.

[0064] Photons arriving at the second end of the first cylindrical light guide

[0065] 12 are redirected to the first end of the second cylindrical light guide

[0066] 13 whose base is located on the protrusion of the prime. The first 12 and the second 13 light guides comprise a light return means 18 corresponding to each window 16 and 17 of the style mask 12. Due to the opposite direction of the photons between the 2 visible parts of the light guides, the light return means 18 positioned along the first light guide 12 and those positioned along the second light guide 13 have opposite angles so that the resulting photon beam follows the same desired direction.

[0067] Figure 6 schematically illustrates coupling constraints between the two cylindrical light guides 12 and 13 according to the optical coupling of Figure 3.

[0068] To have good optical efficiency (physical limit of the principle of total reflection in a translucent medium), one of these constraints is that the curve of the first cylindrical light guide 12 has a positive angle (counterclockwise) relative to the desired lighting direction D. Another of these constraints is that the angle formed by the longitudinal axes of the first and second cylindrical light guides is positive (counterclockwise) relative to the desired lighting direction D, to have good optical efficiency.

[0069] Figure 7 schematically illustrates according to a coupling variant of the two cylindrical light guides 12 and 13 coupled according to the optical coupling of Figure 3.

[0070] According to this variant, the second end of the second cylindrical light guide 13 is mechanically connected to the first light guide 12, for example by means of a rib 21.

[0071] According to a variant, illustrated in figure 8, the optical coupling means 14 comprises a light-reflecting face inclined at an angle less than or equal to 90 degrees.

[0072] Figure 9 schematically illustrates a variant of coupling three light guides, an exemplary embodiment of the present invention.

[0073] According to this example, the second end of the first cylindrical light guide 12 is coupled to the first end of the second cylindrical light guide 13 by the coupling means 14 provided to redirect the photons at an angle of less than 90 degrees. The second end of the second cylindrical light guide 13 is coupled to a first end of a third light guide 19 by a second optical coupling means 20 provided to redirect the photons at an angle of 90 degrees.

[0074] The principle of optical coupling between two light guides by means of optical coupling can be extended to more than three light guides.

[0075] According to one variant, each photon source may, for example, comprise at least one light-emitting diode or at least one laser diode or at least one bulb.

[0076] According to one variant, said at least one photon source is carried by an electronic card.

[0077] 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 card 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 is carried by a plane, i.e. all of the photon sources are carried by this plane. 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.The present invention is therefore not limited to the exemplary embodiments described above but extends in particular to a lighting system which would include secondary characteristics without thereby departing from the scope of the present invention.

[0078] The present invention also relates to a vehicle, for example a motor vehicle or more generally a land motor vehicle, comprising at least one lighting system as described above.

Claims

CLAIMS Lighting system (1) intended to equip a vehicle, comprising - a photon source (11); - a first cylindrical light guide (12) comprising a first end intended to be illuminated by the photon source (11); - a second cylindrical light guide (13) comprising a first end coupled to a second end of the first light guide (12) by an optical coupling means (14) intended to redirect the photons arriving at the second end of the first cylindrical light guide (12) towards the first end of the second cylindrical light guide (13); - an opaque mask (2) comprising windows (16, 17) through which parts of the first and / or second cylindrical light guide are visible; - a light return means (18) being positioned at each part of the first (12) and / or second (13) cylindrical light guide corresponding to a window of the style mask (2) so that photons propagating along the first (12) and / or second (13) cylindrical light guide are redirected towards said window in a desired direction. Lighting system (1) according to claim 1, wherein the optical coupling means (14) and the first end of the second cylindrical light guide (13) are masked. Lighting system (1) according to claim 1 or 2, wherein at least one of said windows is provided with optics or beading. Lighting system (1) according to one of claims 1 to 3, wherein a second end of the second cylindrical light guide (13) is obstructed. Lighting system (1) according to one of the preceding claims, wherein - the first (12) and second (13) cylindrical light guides are superimposed longitudinally on each other at least on one of their parts; - the optical coupling means (14) is adapted to redirect the photons according to a 180 degree angle; - at least one of said windows, called first window (16), has one of its dimensions which is less than a sum of the diameters of the first (12) and second (13) cylindrical light guides; and - at least one of said windows, called second window (17), has one of its dimensions which is at least equal to the sum of the diameters of the first (12) and second (13) cylindrical light guides. Lighting system (1) according to claim 5, wherein the optical coupling means (14) comprises a prism comprising two light-reflecting faces inclined at 45 degrees. Lighting system (1) according to one of claims 5 to 6, wherein the second end of the second cylindrical light guide (13) is mechanically connected to the first light guide (12). Lighting system (1) according to one of claims 1 to 4, wherein the optical coupling means (14) comprises a light-reflecting face inclined at an angle less than or equal to 90 degrees.Lighting system according to one of claims 1-3 or 5-8, which further comprises a third light guide (19) comprising a first end coupled to the second end of the second light guide by a further optical coupling means (20). Vehicle comprising at least one lighting system (1) according to one of the preceding claims.

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