Light guide and component for a vehicle including it

Abstract

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

Description

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

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

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

[0003] To perform very long lighting functions, dynamic or not, which are necessary for example on a dashboard, on rear lights passing through the trunk lid or on the front grille, it is necessary to use several light guides.

[0004] The junction between the light guides is made by simply juxtaposing the guides or by adding intermediate pieces butted between two light guides. However, such junctions cause disturbances in the propagation of light within the resulting light guide, which impairs the homogeneity of the light emitted by the guide. This results in areas that are either too bright or too dark.

[0005] Furthermore, to ensure good homogeneity, light sources must be placed every 400 mm. Therefore, it is only possible to create a cylindrical light guide with a maximum length of 800 mm by placing a light source at both ends of the guide.

[0006] To generate complex shapes with tight rays, a cylindrical light guide cannot go 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 lighting effects, the guide with independently illuminated light segments 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] Prior art guides have the disadvantage of generating disturbances in the propagation of light.

[0009] There is a need to easily produce light guides of significant length and / or which easily allow for dynamic lighting effects.

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

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

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

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

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

[0015] Advantageously, the respective connection portions of two adjacent light guide sections connected to each other are fixed together, thereby improving the bond between the sections connected to each other in the connection zone and thus preventing optical defects in the connection zone. In particular, the respective connection portions of two adjacent light guide sections connected to each other are fixed together by an optical adhesive having the same refractive index as the two guide sections or by welding.

[0016] In particular, the light guide has an overall elongated shape.

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

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

[0019] According to a particular embodiment of the invention, the light guide may have an overall cylindrical external shape and constant (external) diameter, two interlocking connection portions of two adjacent light guide sections forming a junction of cylindrical external shape and 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 together and at least one of said light guide sections comprises several connection portions.

[0021] The invention also relates to a component for a vehicle comprising at least one light guide as described above. In particular, said organ includes 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 above or at least one component as described above.

[0023] Other features and advantages of the invention will become apparent from the following description of a particular embodiment of the invention, given by way of example but not limitation, with reference to the accompanying drawings in which:

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

[0025] [Fig.2] is an enlarged and partially cutaway view of part of [Fig.1].

[0026] [Fig.3] illustrates in right 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 right 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 represent a light guide comprising two light guide sections, each comprising a first and a second adjacent light guide section 1, 2, which are connected to each other by a male-female linkage. Figure 2 illustrates in cutaway view the junction area between the two light guide sections 1, 2, by interlocking their respective connecting portions 10, 20, a portion of the wall of the connecting portion 20 of the second section being removed.

[0029] The first section 1 is formed of a solid cylindrical element, made of a light-transmitting material that allows for internal light guidance, designed in a manner known per se. It is elongated in shape with curved sections, and has a 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 has a constant external diameter. It includes a female connection portion 20 which is of The internal shape is hollow and complementary to the shape of the male connection portion 10 of the first section 1, such 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 arrow F in [Fig. 1]. Thus, the outer face 101 of the male connection portion 10 abuts 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 portion 10 rests against the periphery 201 of the end 201 of the female connection portion 20 (see [Fig. 2]).

[0031] The two connecting portions 10, 20 are held together by an optical adhesive 3, having the same refractive index as the two guide sections 1, 2. The adhesive may be PMMA (polymethyl methacrylate) based if the two light guide sections are made of this material. This adhesive is applied to the interface between the respective surfaces of the male connecting portion 10 and the female connecting portion 20. A thin layer of adhesive is, for example, applied to the surface of the male connecting portion 10.

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

[0033] Figure 3 illustrates, in cross-section, a variant of the respective shapes of a male connection portion 10A and a female connection portion 20A. The positive shape of the male connection portion 10 includes a long rib 100A which fits into a groove 200A of the female connection portion 20A and is complementary in shape to the rib 100A, such that said rib fits into said groove, thereby locking the male connection portion within the female connection portion. These complementary shapes have an anti-rotation effect; they resist the rotation of the first section within the second section.

[0034] Figure 4 illustrates, in right section, another variant of the respective shapes of a male connection portion 10B and a female connection portion 20B. The shape The positive cross of the male connection portion 10B has a four-pronged cross shape that fits into a recessed cross of the female connection portion 20B. This cross shape is complementary to the positive cross, allowing the positive cross to interlock with the female connection portion. These complementary shapes have an anti-rotation effect, preventing the rotation of the first segment within the second segment.

[0035] The invention is not, however, limited to the particular embodiment just described, and especially not to the method of securing the two male and female connection portions. For example, instead of using optical adhesive, 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 the elongated shape of a straight circular cylinder as well as to light guides having an overall elongated shape of another, for example ovoid.

Claims

Demands

1. Light guide comprising two or more of two light guide segments (1,2) assembled together following connections by a male-female link between two adjacent segments, each of said light guide segments (1,2) having at least one connection portion (10, 20, 10A, 20A, 10B, 20B) and said respective connection portions of two adjacent segments connected to each other having complementary shapes fitting into each other; said light guide being characterized in that said respective connection portions (10, 20, 10A, 20A, 10B, 20B) of two adjacent segments connected to each other are fixed together by an optical adhesive having the same optical refractive index as the adjacent segments or by welding.

2. Light guide according to claim 1, characterized in that said respective connecting portions (10A, 20A, 10B, 20B) of two adjacent light guide sections connected to each other have complementary anti-rotational shapes (100A, 200A) fitting into each other.

3. Light guide according to any one of claims 1 to 2, characterized in that it has an overall elongated shape.

4. Light guide according to any one of claims 1 to 3, characterized in that it has a length strictly greater than 800 mm.

5. Component for a vehicle comprising at least one light guide according to any one of claims 1 to 4.

6. Component according to claim 5, characterized in that it comprises a light source (SI, S2) per light guide section (1,2).

7. Motor vehicle characterized in that it comprises at least one light guide according to any one of claims 1 to 4, or at least one component according to any one of claims 5 to 6.

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