Light guide and component for a vehicle comprising it

Abstract

The invention relates to a light guide comprising two or more light guide sections (1, 2) assembled together according to connections by a male-female link between two adjacent sections, as well as a vehicle member comprising it. It also relates to a motor vehicle comprising at least one such light guide, or at least one such member. Figure to be published with the abstract: Fig. 1

Description

Title of the invention: Light guide and member for a vehicle comprising it

[0001] The invention relates to light guides. It relates more particularly to light guides of generally elongated shape, and in particular those used in the field of vehicles, and in particular motor vehicles.

[0002] Light guides within which light can propagate by internal reflection are well known. Light guides of generally elongated shape are increasingly used in the automotive field for lighting with constant light function or with dynamic effect. They are for example installed along the contour of headlights with constant lighting, or for a direction indicator with dynamic light effect by scrolling.

[0003] To perform very long, dynamic or non-dynamic light functions, which are necessary for example on a dashboard, on rear lights crossing the trunk door from one side to the other or on the grille of the front face, it is necessary to use several light guides.

[0004] The junction between the light guides is made by simple juxtaposition of the guides or by adding intermediate pieces abutted between two light guides. However, such junctions cause disturbances in the propagation of light in the light guide thus formed, which is detrimental to the light homogeneity emitted by the guide. This is the cause of areas which are either too bright or too dark.

[0005] Furthermore, to ensure good homogeneity, light sources must be implanted every 400mm. It is therefore only possible to make a cylindrical light guide of 800mm long at most by placing a light source at both ends of the guide.

[0006] To generate complex shapes with tight radii, a cylindrical light guide cannot descend below a radius of curvature less than three or four times the diameter of the guide, otherwise a hole appears which can generate a dark area or a highlighted area.

[0007] To generate dynamic light effects, the guide with light segments that can be lit independently requires more than two light inputs. However, to industrialize a guide with multiple light inputs, the guide and the associated prisms to be manufactured very quickly become impossible to demold.

[0008] The guides of the prior art have the disadvantage of generating disturbances in the propagation of light.

[0009] There is a need to easily produce light guides of im- supporting and / or which easily allow dynamic lighting effects to be obtained.

[0010] The invention aims to solve the problems of light propagation in light guides. It aims to meet the need mentioned above.

[0011] For this purpose, the invention provides a light guide comprising two or more sections of light guide assembled together using connections by a male-female link between two adjacent sections.

[0012] More particularly, each of said light guide sections comprises at least one connection portion and said respective connection portions of two adjacent light guide sections connected to each other have complementary shapes fitting into each other.

[0013] The invention makes it possible to produce a light guide in several sections without creating any disturbance in the propagation of the light.

[0014] Preferably, said respective connection portions of two adjacent light guide sections connected to each other have complementary anti-rotation shapes fitting into each other. In particular, the respective connecting portions of two adjacent sections connected to each other each comprise a flat area which allows for repeatable assembly without rotation of one guide section relative to the other.

[0015] Advantageously, said respective connection portions of two adjacent light guide sections connected to each other are fixed together, which makes it possible to perfect the holding of the sections connected to each other in the connection zone and thus not have an optical defect in the connection zone. In particular, said respective connection portions of two adjacent light guide sections connected to each other are fixed together by an optical glue having the same optical refractive index as that of said two guide sections or by welding.

[0016] In particular, the light guide has a generally elongated shape.

[0017] The invention makes it possible to obtain light guides of great length and / or having dynamic light effect functions.

[0018] According to a particular embodiment of the invention, the light guide has a length strictly greater than 800 mm and / or has a dynamic lighting effect.

[0019] According to a particular embodiment of the invention, the light guide may have a generally cylindrical external shape and a constant (external) diameter, two connection portions fitted into each other, respective of two adjacent light guide sections, forming a junction of cylindrical external shape and an external diameter equal to that of the guide.

[0020] According to a particular embodiment of the invention, the guide according to the invention may comprise more than two light guide sections connected to each other and at least one of said light guide sections comprises several connecting portions.

[0021] The invention also relates to a member for a vehicle comprising at least one light guide as described previously. In particular, said member comprises a light source per section of light guide.

[0022] The invention also relates to a motor vehicle comprising at least one light guide as described previously or at least one member as described above.

[0023] Other features and advantages of the invention will emerge from reading the description given below of a particular embodiment of the invention, given for informational purposes but not as a limitation, with reference to the appended drawings in which:

[0024] [Fig. 1] is a perspective and exploded view of a light guide according to one embodiment of the invention.

[0025] [Fig.2] is an enlarged and partially cutaway view of a portion of [Fig.l].

[0026] [Fig.3] illustrates in cross section, a variant of respective shapes of the male-female connections of a light guide according to an embodiment of the invention.

[0027] [Fig.4] illustrates in cross section, another variant of respective shapes of the male-female connections of a light guide according to an embodiment of the invention.

[0028] Figures 1 and 2 show a light guide comprising two light guide sections comprising a first and a second adjacent light guide section 1, 2 which are connected to each other according to a connection by a male-female link. [Fig.2] illustrates in cutaway the junction zone between the two light guide sections 1, 2, by fitting their respective connection portions 10, 20, a part of the wall of the connection portion 20 of the second section being removed.

[0029] The first section 1 is formed from a solid cylindrical element, made of a material that allows light to pass through and allows the internal guidance of the light, designed in a manner known per se. It is of elongated shape having curved zones, of constant external diameter except at one of its ends which constitutes the male connection portion 10. This connection portion 10 thus has a diameter smaller than the diameter of the rest of said first guide section.

[0030] The second section 2 is formed from a solid cylindrical element designed like the first section 1. It has an elongated shape with curved areas, and it is of constant external diameter. It comprises a female connection portion 20 which is of hollow internal shape and complementary to the shape of the male connection portion 10 of the first section 1 so that the male connection portion 10 of said first section fits completely into the female connection portion 20 of said second section, as indicated by the arrow F in [Fig.l]. Thus, the end face 101 of the male connection portion 10 comes into abutment against the internal face 202 of the hollow female connection portion 20 (see [Fig.2]). Similarly, the periphery 102 located at the base of the positive shape of said male connection portion10 bears against the periphery 201 of the end 201 of the female connection portion 20 (see [Fig.2]).

[0031] The two connection portions 10, 20 are held fixed to each other by an optical glue 3, having the same refractive index as that of the two guide sections 1, 2. The glue can be based on PMMA (poly methyl methacrylate) if the two light guide sections are made of this material.This glue is applied to the interface between the two respective surfaces of the male 10 and female 20 connection portions. A thin layer of glue is for example applied to the surface of the male connection portion 10.

[0032] The light guide formed by the two light guide sections 1, 2 has an external diameter in the junction zone which is identical to the diameter of the parts respectively of the two guide sections 1, 2 immediately adjacent to said junction. The light (arrow L1) coming from a light source SI, for example of the LED type, placed at the free end 11 of the first section 1, as indicated in [Fig.l], is thus guided homogeneously from one section 1 to the other section 2 via this junction zone. The second section 2 guides a light L2 (arrow L2) coming from a light source S2, for example of the LED type, placed at a free end 21 of the second section 2, as shown in [Fig.l]. The light L1 guided from the first section 1 can thus either be combined with the light L2 arriving in the second section 2, or be used alone to be guided in the second section 2, or alternately, depending on the desired lighting effects.

[0033] [Fig. 3] illustrates in cross section, a variant of respective shapes of a male connection portion 10A and a female connection portion 20A. The positive shape of the male connection portion 10 comprises an elongated rib 100A which is included in a groove 200A of the female connection portion 20A and of complementary shape to the rib 100A so that said rib fits into said groove, which makes it possible to block the male connection portion in the female connection portion. These complementary shapes have an anti-rotation action, they oppose the rotation of the first section in the second section.

[0034] [Fig.4] illustrates in cross section, another variant of respective shapes of a male connection portion 10B and a female connection portion 20B. The positive shape of the male connection portion 10B has a four-pointed cross shape. which is included in a hollow cross of the female connection portion 20B of complementary shape to said positive cross so that said positive cross fits therein, which makes it possible to block the male connection portion in the female connection portion. These complementary shapes have an anti-rotation action, they oppose the rotation of the first section in the second section.

[0035] The invention is however not limited to the particular embodiment which has just been described, and in particular by the method of holding between the two male and female connection portions. For example, instead of using an optical glue, the two connection portions can be held together by welding. For example, the welding can be carried out by heating the surface of the male connection portion, or by a vibration welding method between the two portions or by laser welding.

[0036] The invention can in particular be applied to light guides of elongated shape of right circular cylinder as well as to light guides having another generally elongated shape, for example ovoid.

Claims

Claims

1. Light guide comprising two or more light guide sections (1, 2) assembled together according to connections by a male-female link between two adjacent sections.

2. Light guide according to claim 1, characterized in that each of said light guide sections (1, 2) comprises at least one connection portion (10, 20, 10A, 20A, 10B, 20B) and said respective connection portions of two adjacent sections connected to each other have complementary shapes fitting into each other.

3. Light guide according to claim 2, characterized in that said respective connection portions (10A, 20A, 10B, 20B) of two adjacent light guide sections connected to each other have complementary anti-rotation shapes (100A, 200A) fitting into each other.

4. Light guide according to any one of claims 2 to 3, characterized in that said respective connection portions (10, 20, 10A, 20A, 10B, 20B) of two adjacent light guide sections connected to each other are fixed together.

5. Light guide according to claim 4, characterized in that said respective connection portions (10, 20, 10A, 20A, 10B, 20B) of two adjacent light guide sections connected to each other are fixed together by an optical glue having the same optical refractive index as that of the adjacent sections or by welding.

6. Light guide according to any one of claims 1 to 5, characterized in that it has a generally elongated shape.

7. Light guide according to any one of claims 1 to 6, characterized in that it has a length strictly greater than 800 mm and / or in that it has a dynamic lighting effect.

8. A member for a vehicle comprising at least one light guide according to any one of claims 1 to 7.

9. Organ according to claim 8, characterized in that it comprises a light source (S1, S2) per section of light guide (1, 2).

10. Motor vehicle characterized in that it comprises at least one light guide according to any one of claims 1 to 7, or at least one member according to one of claims 8 to 9.

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