Vehicle steering wheel lighting device having compact design and light guide

Abstract

The present invention provides a light bar (40) for a vehicle steering wheel, comprising: - a plurality of light sources, such as LEDs (15); a diffuser (12) arranged to diffuse light from a plurality of light sources (15) towards an occupant of the vehicle; a light guide (14), the light guide (14) being disposed between a plurality of light sources (15) and the diffuser (12), the light guide (14) comprising a common exit surface (14e) and a plurality of optical portions each having an entrance surface (14c) disposed facing each of the light sources (15); The present invention relates to a light bar (40), characterized in that the light guide (14) further comprises a plurality of deflection surfaces (14r) each disposed between each entrance surface (14c) and the common exit surface (14e) so as to cause a change in the main direction of the light.

Description

[Technical field]

[0001] The present invention relates to a lighting device to be mounted on the steering wheel rim of a motor vehicle. [Background technology]

[0002] Illumination devices installed in steering wheel rims are known in the prior art. Document WO 2019 / 137699 discloses a steering wheel illumination device which is large in size and the light may have hot spots and inhomogeneities. Summary of the Invention [Problem to be solved by the invention]

[0003] One object of the present invention is to address the disadvantages of the prior art mentioned above, and in particular to propose, firstly, a lighting device for a steering wheel rim, which limits or eliminates the visual defects of light diffusion while limiting the size of the lighting device in order to incorporate it in a steering wheel rim whose dimensions are limited and reduced.

[0004] To this end, a first aspect of the invention is a light bar for a vehicle steering wheel, comprising: -Multiple light sources such as LEDs a diffuser positioned to diffuse light from a plurality of light sources toward an occupant of the vehicle; a light guide arranged between a plurality of light sources and a diffuser, and comprising a plurality of optical portions each having a common exit surface and an entrance surface arranged facing each of the light sources, characterized in that the light guide further comprises a plurality of deflection surfaces each arranged between each entrance surface and the common exit surface so as to cause a change in the main direction of the light.

[0005] The term "light direction" is understood to mean the direction of the light relative to the light guide. Diffuser is understood to mean an optical element arranged to diffuse the light, i.e. one of the surfaces of the optical element is visible to the occupant or end user, unlike a light guide arranged to transmit the light inside the device where the surface of the optical element is not visible to the end user.

[0006] The term "redirecting light" means directing light in a new main direction. In other words, the light has a first main direction at each of the exits of the light sources and at each entrance surface of the light guide, and a second main direction at each deflection surface on the exit side, at the exit surface of the light guide, and at the entrance surface of the diffuser. Thus, the light is redirected between the entrance surface and the exit surface. Redirection of light should be distinguished from dispersion of light, where the dispersed light no longer has any main direction. Redirection of light should be distinguished from dispersion of light, in that the main purpose of dispersion is to avoid light concentration (typically hot spots) due to the light being dispersed in several directions. In other words, the incident light rays are redirected in different ways and in different directions. The main purpose of light redirection is to redirect light, i.e. to redirect most, preferably all, of the incident light rays in the same way (i.e. to apply the same transformation to most, preferably all, of the incident light rays). In this document, there is talk of folding the optical system so that the optical path is longer than the size of the system itself.

[0007] A bar is understood to mean an elongated part, preferably curved along a curvature similar to that of the steering wheel, so that it can be integrated into the steering wheel, in particular into the rim of the steering wheel.

[0008] This makes it possible to propose a compact light bar, respecting the limited space of the steering wheel rim (specifically its depth along the rotation axis of the steering wheel), while improving the light guidance and diffusion towards the user and by improving the light homogeneity. In addition, this makes it possible to propose a very slim light device with reduced size, with high light homogeneity criteria. The key feature to obtain a high degree of homogeneity is to have the longest possible light guidance length. Thus, good quality light animation and dynamic light effects are obtained, while having a uniform light mixing in a small mechanical size with an optimized number of light sources.

[0009] In other words, the present invention is a light bar for a vehicle steering wheel, comprising: -Multiple light sources such as LEDs a diffuser positioned to diffuse light from a plurality of light sources toward an occupant of the vehicle; a light guide arranged to guide light from the plurality of light sources to a diffuser; a common exit surface disposed between the light sources and the diffuser; at least one entrance surface arranged between a plurality of light sources and a common exit surface, The present invention relates to a light bar, characterized in that the light guide further comprises at least one deflection surface arranged between the at least one entrance surface and the common exit surface so as to cause a change in the main direction of the light.

[0010] Preferably, the common exit surface may be arranged facing the diffuser.

[0011] Preferably, at least one entrance surface may be positioned to collect light emitted by the light source and / or may be positioned facing the light source.

[0012] Preferably, a single common entrance surface may be arranged to collect light emitted by the light sources and / or may be arranged facing the light sources.

[0013] Advantageously, the diffuser may be arranged to define the outer surface of the steering wheel rim.

[0014] Advantageously, light entering the diffuser may have a main direction of light at the entrance of the diffuser, and the light source may have an offset relative to the diffuser in a direction perpendicular to the main direction of light at the entrance of the diffuser.

[0015] According to one embodiment, at least one light source of the plurality of light sources is arranged to emit visible light. According to one embodiment, each light source of the plurality of light sources is arranged to emit visible light. Light is considered to be visible if its wavelength is between 380 nm and 780 nm. In particular, the light bar according to the present invention may not be provided for monitoring activities of users using measuring devices or light sources emitting invisible light (ultraviolet and / or infrared).

[0016] According to one embodiment, a light bar may be provided to transmit or display information to a user of the vehicle, particularly the driver.

[0017] According to one embodiment, the light guide may have an L-shaped cross section.

[0018] According to one embodiment, the light guide may have a collecting surface positioned facing one or more light sources.

[0019] According to one embodiment, the collection surface may have a collection surface height that is higher than the height of the light source, which makes it possible to limit unwanted light rays that are not collected by the light guide.

[0020] According to one embodiment, the collection surface may be perpendicular to the main direction of light emitted by the light source.

[0021] According to one embodiment, the collection surface may have a collection surface height of less than 3 mm, preferably less than 2.5 mm, normal to the light collection direction and / or tangential to the collection surface and / or along the light deflection direction and / or along the light diffusion direction.

[0022] According to one embodiment, the light guide may have a deflection surface that is inclined relative to the light collection surface. According to one embodiment, the deflection surface may be inclined 45°±10° relative to the light collection surface.

[0023] According to one embodiment, the deflection surface may have a height equal to about ±10% of the height of the light collecting surface. This implementation allows for a correct redirection of all collected light.

[0024] According to one embodiment, in the normal direction to the light collecting surface, the deflection surface may have a length equal to at least 95% of the height of the light collecting surface.

[0025] Advantageously, the diffuser has a major axis parallel to its arc of curvature, and the light source may be offset relative to the diffuser in a direction perpendicular to the major axis of the diffuser.

[0026] Advantageously, the diffuser comprises a contact surface with the light guide and has a major axis perpendicular to the contact surface, and the light source may be offset relative to the diffuser in a direction perpendicular to the major axis of the diffuser.

[0027] Advantageously, the offset is greater than the thickness of the light guide.

[0028] This makes it possible to optimise the size of the light bar and to ensure good homogeneity of the light due to the extension of the light path by folding.

[0029] Advantageously, the deflection surfaces form a common deflection surface.

[0030] Advantageously, the optical portions may each comprise a separate deflecting surface.

[0031] This makes it possible to optimise the size of the light bar and to ensure good uniformity of the light, and to make it suitable for any type of light source, in particular side-emitting or upward-emitting sources.

[0032] Advantageously, the light guide may further comprise a dispersion pattern on at least one of the entrance surface, the deflection surface of the optical part, or the common exit surface.

[0033] Advantageously, the dispersion pattern of the entrance surface may be arranged facing the light source.

[0034] Advantageously, the dispersion pattern of the common exit surface may cover the entire common exit surface.

[0035] Advantageously, the distribution pattern of the deflection surfaces may cover all of the deflection surfaces.

[0036] Advantageously, the dispersion pattern of the deflection surface may have a pattern depth of 0.02 mm to 0.1 mm inclusive and a pattern period of 0.5 mm to 1 mm for the deflection surface pattern, and a pattern depth of 0.1 mm to 0.5 mm and a pattern period of 0.2 mm to 1 mm for the entrance surface and exit surface.

[0037] This improves the light diffusion in a compact light bar while limiting light hot spots and optimizing light distribution. The light dispersion is performed in an axis perpendicular to the propagation direction of the light rays in the light guide, so that the light beam emission reaches (or impinges) the diffuser homogeneously. In other words, the function of the dispersion pattern is to make the propagation direction of the light rays in the light guide scattered or random. As a result, the paths of the various light rays are highly inhomogeneous and multidirectional in the light guide, so that the light reaches the emission or "downstream" surface of the light guide homogeneously. Even if the surface of the light bar is elongated, the user does not perceive differences in emission, emissivity, or light output along the light bar.

[0038] Advantageously, the deflection surface is inclined with respect to the entrance surface.

[0039] Advantageously, the angle between the plane of incidence and the plane of deflection may be 45 degrees ±10 degrees, preferably ±5 degrees.

[0040] This makes it possible to optimize the optical properties of the light bar and improve its size and mechanical strength.

[0041] Advantageously, the light bar may further comprise arches disposed along the light bar between the optical portions, and preferably the light bar may further comprise at least one centering part, such as a centering hanger, abutting against at least one of the arches to support the arch. Preferably, the hanger has a shape opposite to that of the arch it supports. The hanger may also have another shape capable of supporting the arch.

[0042] Advantageously, the light bar may further comprise mounting legs.

[0043] Advantageously, the light bar may further comprise a pin, preferably a headed pin.

[0044] Heading is a hot deformation in which the pin can be heated (eg like a rivet) by ultrasound or laser.

[0045] Advantageously, the pins may be arranged to connect the light guide to a printed circuit that supports the light source.

[0046] This allows for improved positioning of the light guide relative to the light source, which is important for obtaining good homogeneity.The arch may more generally be an opening.

[0047] Advantageously, at least one of the deflection surfaces may have an approximate radius of curvature greater than a predetermined value, typically 150 mm.

[0048] Advantageously, the entrance surface of at least one of the optical parts is perpendicular to the light emission direction of the multiple light sources.

[0049] Advantageously, the entrance surface of at least one of the optical parts is arranged to block secondary light from the multiple light sources directly to the diffuser, such that no light rays from the light sources can reach the diffuser directly, in other words, the entrance surface of at least one of the optical parts is arranged to prevent any radiation from the multiple light sources from directly approaching the diffuser.

[0050] This allows for improved optical performance while increasing the compactness of the light bar.

[0051] A second aspect of the invention relates to a vehicle steering wheel comprising a light bar according to the first aspect.

[0052] This makes it possible to propose a vehicle steering wheel with a compact light bar, which takes into account the limited size of the steering wheel rim, while improving the guidance and diffusion of light towards the user and by improving the homogeneity of the light.

[0053] A third aspect of the invention relates to a vehicle comprising a vehicle steering wheel according to the second aspect.

[0054] This makes it possible to propose a vehicle with a vehicle steering wheel with a compact light bar, taking into account the limited size of the steering wheel rim, while improving the guidance and diffusion of light towards the user and by improving the homogeneity of the light. [Brief description of the drawings]

[0055] Other characteristics and advantages of the present invention will become more apparent on reading the following detailed description of embodiments of the invention, given by way of example but in no way limiting, as illustrated by the accompanying drawings in which: [Figure 1] FIG. 2 is a front view of a steering wheel equipped with an illumination device on the rim. [Diagram 2]FIG. 2 shows a front view of a steering wheel with lighting devices in the rim, without the leather cover shown. [Diagram 3] FIG. 3 shows a cross-section of the rim with the lighting device along section II. [Figure 4] FIG. 4 shows a perspective view of a holder for the lighting device. [Diagram 5] FIG. 5 shows a perspective view of a portion of a lighting device seen from a first side. [Figure 6] FIG. 6 shows a perspective view of a portion of a lighting device viewed from opposite the first side. [Figure 7] FIG. 7 shows a perspective detailed view of a portion of the lighting device from a first side. [Figure 8] FIG. 8 shows another detailed perspective view of a portion of the lighting device from a first side. [Figure 9] FIG. 9 shows another detailed top view of a portion of the lighting device. [Figure 10] FIG. 10 shows a detailed perspective view of a part of a lighting device according to the second embodiment seen from a first side. [Figure 11] FIG. 11 shows a detailed perspective view of a part of a lighting device according to the second embodiment seen from the opposite side to the first side. [Figure 12] FIG. 12 shows a schematic cross-sectional view of a part of an illumination device according to a second embodiment. [Figure 13] FIG. 13 shows another detailed elevational view of the lighting device according to the second embodiment seen from the opposite side to the first side. [Figure 14] FIG. 14 shows a detailed view of the profile of the dispersion pattern of the illuminator, adapted to the deflection surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0056] FIG. 1 shows a front view of a steering wheel with a lighting device within the rim.

[0057] FIG. 1 shows a front view of a steering wheel 1 with a lighting device 40 (or light bar 40 ) within the rim 10 .

[0058] Thus, FIG. 1 shows a vehicle steering wheel 1 typically comprising a rim 10 connected to a hub 20 by several arms 30. The rim 10 is equipped with a lighting device 40 (or light bar 40) in an upper position, also known as the "12 o'clock" position. This lighting device 40 has an external display wall 12a of a diffuser 12 that extends along the rim 10 over an angular sector of approximately 60° to 80°, but it is possible to provide a larger or smaller angular range, for example up to 180° or even more, or even less than 60°. The steering wheel rim further comprises a cover such as leather (or artificial leather, or other). The term "diffuser 12" is understood to mean a part visible to the vehicle occupant, which uses two materials, one of which diffuses, and which transmits light in whole or in part. It is therefore possible to provide the diffuser 12 as a screen, part of which is diffusive.

[0059] Section II of the rim 10 is provided to show a cross-sectional view of the rim along I-I in FIG.

[0060] FIG. 2 shows a front view of the steering wheel 1 with a lighting device 40 in the rim 10, the cover 18 of the steering wheel 1 not being shown.

[0061] Reference numbers have been preserved wherever possible between drawings and embodiments, where appropriate.

[0062] FIG. 3 shows a cross-section of the rim 10 with a lighting device 40 along section II.

[0063] The lighting device 40 comprises a holder 11 having an inner wall 11p and at least one opening 11o.

[0064] The lighting device 40 further comprises at least one light source 15 arranged to emit light, such as a number of light sources (e.g. LEDs). The lighting device 40 also comprises a diffuser 12 (or light diffuser 12) arranged to diffuse the light coming from the light source 15 towards the vehicle occupants. In other words, the diffuser 12 diffuses the light towards the user, i.e. its outer surface or external display wall 12a is the surface directly seen by the user.

[0065] The lighting device 40 (or light bar 40) further comprises a light guide 14 arranged to guide the light emitted by the light source 15 towards the diffuser 12. The light guide 14 is arranged between the light source 15 and the diffuser 12.

[0066] The light guide 14 comprises a number of optical parts with an entrance surface 14c (also called collection surface 14c) each arranged facing each of the light sources 15. The light guide 14 thus comprises several light collecting surfaces 14c arranged on the light source 15 side and a common emission surface 14e on the diffuser 12 side. The light guide 14 just passes through an opening 11o in the inner wall 11p of the holder 11. More specifically, the collection surface 14c of the light guide 14 is arranged on a first side of the opening 11o and the emission surface 14e is arranged on a second side of the opening 11o.

[0067] In other words, the light guide 14 is disposed between the collection surface 14c and the emission surface 14e, and includes a transmissive portion disposed within the opening 11o. The inner wall 11p is thus disposed between the light source 15 and the diffuser 12.

[0068] The light guide 14 is engaged with the diffuser 12 to shape the diffuser 12 to a predetermined size, but this is not required. In fact, the diffuser 12 is a thin piece and an arc, and therefore may twist or flip both during assembly and use, which may damage or distort other parts of the rim 10, or cause defective points in the diffusion of light, which is not only unsightly but also ineffective in accurately conveying information to the user.

[0069] The light guide 14 and the diffuser 12 may each comprise a coupling portion arranged to fit together, i.e. the light guide 14 and the diffuser 12 may be in contact, the light guide 14 may support the diffuser 12, but the light guide 14 may also engage with the diffuser 12 to lock its movement. We refer to the light guide 14 acting as a centering pin in the light guide 12 with lateral guide walls 12g.

[0070] Thus, the diffuser 12 is an optical element arranged to diffuse light and one of its surfaces (here the external display wall 12a) is visible to the end user, as opposed to a light guide arranged to transmit light to the interior of the device, which does not have any surfaces visible to the end user.

[0071] Furthermore, the light guide 14 has a common exit surface for the light coming from the multiple light sources 15. The light guide 14 is therefore disposed between the multiple light sources 15 and the diffuser 12.

[0072] Each optical portion of the light guide 14 comprises a deflection surface 14r. Thus, the light guide 14 comprises a number of deflection surfaces 14r, each disposed between a respective collection surface 14c (also called entrance surface 14c) and a respective emission surface 14e (also called exit surface 14e) to produce a change in the main direction of the light. This is particularly useful for using the maximum amount of space available in the cross section of the rim 10 shown in Figure 3. Without this deflection, the light source would need to be positioned lower in the rim to maintain the same light homogeneity in a light guide without deflection.

[0073] This makes it possible to propose a very slim lighting device 40 with reduced size, since there is very little space available at the rim 10, which also provides very high luminous flux homogeneity criteria. In particular, the key characteristic for obtaining a reasonable homogeneity is to have a reasonable light guide length. Thus, the problem of obtaining good quality light animation and dynamic light effects with light sources, while having a uniform light mixing at a small mechanical size with a reduced number of possible light sources, is solved.

[0074] The deflection surface 14r is preferably inclined at 45 degrees ±5 degrees with respect to the light collecting surface 14c, which (also called the entrance surface 14c) is preferentially perpendicular to the light emitting surface 14e (also called the exit surface 14e).

[0075] The light device 40 (or light bar 40) comprises a printed circuit 16 having a main plane, passing through axes HH and hh and perpendicular to axis VV. The emission surface 14e is preferably parallel to the plane HH-hh, and the light collection surface 14c is preferably parallel to axis VV. The deflection surface 14r is preferably inclined at 45 degrees ±5 degrees with respect to axis VV.

[0076] The embodiment of the light guide 14 having a single deflecting surface 14r is particularly suitable for laterally emitting light sources 15.

[0077] The lighting device 40 further comprises a printed circuit board 16 (PCB) connected to and controlling the light source 15 .

[0078] The steering wheel rim 10 further comprises a cover 18 , such as leather (or artificial leather or other), and foam 17 .

[0079] The rim 10 may further include electronics 19 beneath the cover 18, such as a presence sensor (capacitive, resistive, or other) and / or a heating element, although a heating element is not required.

[0080] For example, the width of the printed circuit 16 in the plane HH-hh is 14 mm in a particular embodiment, and the height between the lower surface of the printed circuit 16 and the external display wall 12a is 12 mm. In view of the reduced size of the rim 10, it is advantageous to have a light device 40 that is as compact as possible.

[0081] FIG. 4 shows a perspective view of the holder 11 of the lighting device 40. As shown in FIG.

[0082] The holder 11 is provided with a mounting portion 11a at the bottom (or on its inner surface) to allow for the guidance of a power cable (not shown), although this is not essential.

[0083] The retainer 11 is also provided with holes 11b to leave passages for the clips 12c of the diffuser 12 to attach them together when the clips 12c of the diffuser 12 are inserted into the retainer 11 from the top. The diffuser 12 provided with the clips is then engaged with the protrusions 11h of the retainer 11.

[0084] The holder 11 further comprises a blank 11 c for supporting the cover 18 .

[0085] FIG. 5 shows a perspective view of a portion of a lighting device 40 as viewed from a first side, ie, the side of the light source 15, ie, from the center of the arc formed by the light guide 14. In FIG.

[0086] The light emitting surface 14 e (also called the exit surface 14 e ) of the light guide 14 is a common surface that guides light from multiple light sources 15 .

[0087] The light guide 14 is provided with an opening 14a, such as an arch 14a, for example to accommodate one or more microcontrollers 110 of the lighting device 40. Locating interfaces or headed pins 113 for centering and / or mounting the light guide 14 onto the printed circuit 16 are also provided, which can cooperate with the light guide 14 in the opening 14.

[0088] The lighting device 40 further comprises a connector 112 on the printed circuit 16 for connecting it to other components of the steering wheel 1 .

[0089] The light guide 14 also includes shaped protrusions 111 which act as a retention interface between the light guide 14 and the retainer 11, although these features are not required.

[0090] 6 shows a perspective view of a portion of lighting device 40 from the opposite side to the first side, in other words the opposite view to that of FIG.

[0091] The deflecting surface 14r of the light guide 14 is shown.

[0092] The deflection surface 14r, the light collecting surface 14c, and / or the light emitting surface 14e can be provided with a dispersion pattern, as can be seen in the other figures. Depending on whether the dispersion pattern is present on the deflection surface 14r, the light collecting surface 14c, and / or the light emitting surface 14e, the dispersion pattern can have the same or different shapes.

[0093] Preferentially, the dispersion pattern is present at the entrance and exit faces so as to capture the maximum amount of emitted light and homogenize it.

[0094] These distribution patterns "burst" the light for uniform rendering, thus helping to reduce hot spots. These patterns can preferably cover the entire light emitting surface 14e, not just facing the light source 15 at the entrance.

[0095] On the deflection surface 14r, the dispersion pattern can cover the entire surface to avoid hot spots without affecting the brightness.

[0096] Preferably, to maintain reflection and to avoid shadowing and multiple reflections, the scattering pattern (or striations) on the deflecting surface 14r has a shallow depth and prominent shape, allowing some of the light rays to be returned to the light source 15. The scattering pattern may have a height of 0.02-0.1 mm and a period of 0.5-1 mm.

[0097] FIG. 7 shows a perspective detailed view of a portion of the lighting device 40 (or light bar 40) from a first side.

[0098] The light source 15 emits light towards the light collecting surface 14c (also called the entrance surface 14c) of the light guide 14. The light is redirected by the deflecting surface 14r towards the common surface 14e, the light emitter, which re-emits the light towards the diffuser 12.

[0099] An opening 14a (such as an arch 14a) in the light guide 14 is provided to accommodate a microcontroller 110 of the lighting device 40 or other electronic component. A positioning interface 113 is used to center and / or attach the light guide 14 to the printed circuit 16.

[0100] The light source 15 emits light in a main direction parallel to the main plane "HH-hh" of the printed circuit 16. The deflection surface 14r redirects the main direction of the light so that it is perpendicular to the main direction of the printed circuit 16. The main surface of the common light emitting surface 14e is substantially parallel to the main surface of the printed circuit 16, although corrugations or any other distribution pattern may be provided, although this is not required.

[0101] Furthermore, to limit parasitic rays traveling directly from the light source 15 to the emission surface 14e or diffuser 12, it is possible to provide the collection surface 14c with a light collection surface height 100 that is greater than the height of the light source 101.

[0102] Preferably, the collection surface 14c is perpendicular to the main direction of light emitted by the light source 15 so as to confine the light burst in the direction of the axis VV. The axis VV is perpendicular to the axis HH. The printed circuit 16 has a main plane passing through the axes HH and hh.

[0103] FIG. 8 shows another detailed perspective view of a portion of lighting device 40 from a first side.

[0104] The light source 15 faces the light collecting surface 14c of the light guide 14. The light source 15 emits light in the direction of the collecting surface 14c, where the light is redirected by the deflecting surface 14r towards the emission surface 14e.

[0105] The light guide 14 is provided with a radius of curvature 14q on the side of the collecting surface 14c opposite the deflecting surface 14r. The radius of curvature 14q is preferably smaller than 2 mm, very preferably smaller than 1 mm. This makes it possible to reduce the effect of the radius of curvature 14q on the path of the light when it is redirected by the deflecting surface 14r.

[0106] In one embodiment, the distribution pattern on the collection surface 14c serves to distribute hot spots of the light sources 15 by changing the natural Lambertian distribution of the light sources 15 (specifically LEDs), which is maximum at the center, to a more uniform distribution by deflecting the light outwards from the axis. Preferably, the design is triangular, preferably with an angle of 20-45° to the main optical axis. The tip of the triangle has a rounded appearance with a radius of curvature of 0.05-0.1 mm. The light beam at the tip of the triangle allows the light to pass through the center. The width of the triangle is preferably less than 0.5 mm, so that it is smaller than the LED chip and is better at bursting light.

[0107] FIG. 9 shows another detailed top view of the light device 40 and a portion of the light guide 14.

[0108] In one embodiment, the emission surface 14e common to the light of all light sources 15 has a dispersion pattern as follows: These patterns are used to further homogenize the light beam. Preferably, the patterns are projecting arcs. The pattern can be similar to that of the 45° deflection surface, but with a more pronounced curvature and the deflection can be 0.1 mm to 0.5 mm with a pitch of 0.5 mm. A width of 0.5 mm allows the created secondary light sources to be placed closer to each other under the diffuser 12. A width of less than 1 mm can be appropriate. Less than 0.2 mm can increase the tooling costs rapidly.

[0109] Further, the diffusing material can be characterized as follows.

[0110] The level of diffusion of a material can be measured by two characteristics. The first is the haze, described in the standard ASTM D1003. It is the percentage of light emitted more than 2.5° from the normal direction. Transparent materials have a haze close to 0%, while the haze of diffusing materials is almost 100%. For example, optical materials for headlights in the United States (listed as AMECA) are imposed with a haze of less than 30%, even after UV aging. The second characteristic is the half-power angle, i.e. the half-angle of diffusion. It is the angle at which the intensity is 50% of the maximum for a collimated incident ray on a sample of the material. The diffusing materials of the screen and diffuser 12 preferably have a haze of more than 80% and a half-angle of diffusion more than 15°, preferentially more than 40°. The materials of the light guide 14 preferably have a haze less than 30% and a low half-angle of diffusion, preferably less than 5°.

[0111] FIG. 10 shows a detailed perspective view of a part of a lighting device 40 according to a second embodiment seen from a first side.

[0112] In this embodiment, the light source 15 is positioned to emit light towards the light collecting surface 14c. The main direction of the light is perpendicular to the main plane of the printed circuit 16 and is redirected by the second deflection surface 14R of the light guide 14. The second deflection surface 14R (also called the other deflection surface 14R) directs the light towards the deflection surface 14r, which redirects the light towards the common light emitting surface 14. The light thus undergoes several deflections. The lighting device 40 is therefore particularly compact, which is important with regard to the installation of the lighting device 40 in the rim 10. Thus, the optical parts may each comprise a second deflection surface 14R (or other deflection surface 14R), so that the light guide 14 may comprise a plurality of second deflection surfaces 14R.

[0113] The embodiment of the light guide 14 having two turning surfaces 14r, 14R is particularly suitable for top-emitting light sources 15 (or emitting at the top of the light source 15).

[0114] 11 shows a detailed perspective view of a portion of a lighting device 40 according to a second embodiment as viewed from the opposite side to the first side, in other words the opposite view to that of FIG.

[0115] The light guide 14 includes legs 14p, preferably two legs 14p, positioned around each light source 15 to not only support the light guide 14 but also to prevent lateral parasitic light.

[0116] FIG. 12 shows a schematic cross-sectional view of a portion of an illumination device 40 according to a second embodiment.

[0117] The light source 15 is positioned on the printed circuit 16, with the main direction of the light perpendicular to the main plane of the printed circuit 16. The second deflecting surface 14R (also called the other deflecting surface 14R) redirects the light towards the deflecting surface 14r, which in turn redirects the light towards the light emitting surface 14e.

[0118] FIG. 13 shows another detailed elevational view of the lighting device 40 according to the second embodiment as seen from the opposite side to the first side.

[0119] The deflection surface 14r of the light guide 14 is shown along with the opening 14a, and the light exit surface 14e is shown.

[0120] FIG. 14 shows a detailed view of the dispersion pattern of the illumination device 40, adapted to the deflection surface 14r and generally applicable to all embodiments.

[0121] In one embodiment, the dispersion pattern of the deflection surface 14r makes it possible to improve the homogeneity of the light as follows: The role of the dispersion pattern is to disperse the light rays around their main direction. This surface acts to reflect, so the deflection angle is twice the angle of incidence. A deflection of less than 0.1 mm can be provided over a pitch of 0.5 mm. In addition, the radius must remain small in order to maintain total internal reflection and to prevent light from passing through the surface. The width of the pattern is 0.2-1 mm, and the surface can be inclined, preferably at 40°-50°.

[0122] Unless contradictory, all embodiments can be combined.

[0123] It will be understood that various modifications and / or improvements, which will be apparent to those skilled in the art, may be made to the various embodiments of the invention described herein without departing from the scope of the invention, which is defined in the appended claims.

[0124] In particular, it refers to expanding or contracting the arc of the diffuser 12 in order to adjust the angle of the deflecting surface 14r, of the second deflecting surface 14R, or of the bevel. It also refers to the possibility of having several light emitting surfaces instead of a common surface.

Claims

1. A light bar (40) for a vehicle steering wheel (1), comprising: - a number of light sources (15), such as LEDs; a diffuser (12) arranged to diffuse the light from said plurality of light sources (15) towards the occupants of the vehicle; a light guide (14) arranged between said light sources (15) and said diffuser (12), said light guide (14) comprising a common exit surface (14e) and a plurality of optical parts each having an entrance surface (14c) arranged facing each of said light sources (15), 4. The light bar, characterized in that the light guide (14) further comprises a plurality of deflection surfaces (14r) each disposed between each entrance surface (14c) and the common exit surface (14e) so as to cause a change in the main direction of the light.

2. The light bar of claim 1 , wherein the diffuser (12) is arranged to form an outer surface of a steering wheel rim (10).

3. Light entering the diffuser (12) has a main direction of light at the entrance of the diffuser (12); The light bar of claim 1 or 2, wherein the light source (15) has an offset relative to the diffuser (12) in a direction perpendicular to the main direction of the light at the entrance to the diffuser (12).

4. The light bar according to any one of claims 1 to 3, wherein the optical portions each comprise a separate deflection surface (14R).

5. The light bar according to any one of claims 1 to 4, wherein the light guide (12) further comprises a dispersion pattern on at least one of the entrance surface (14c), the deflection surface (14r) of the optical part, or the common exit surface (14e).

6. The light bar of claim 5, wherein the dispersion pattern of the entrance surface (14c) is arranged facing the light source (15).

7. The light bar according to claim 5 or 6, wherein the distribution pattern of the common exit surface (14e) covers the entire common exit surface (14e).

8. The light bar according to any one of claims 5 to 7, wherein the distribution pattern of the deflection surfaces (14r) covers all of each deflection surface (14r).

9. The light bar according to any one of claims 5 to 8, wherein the dispersion pattern of the deflection surface (14r) has a pattern depth of 0.02 mm to 0.1 mm and a pattern period of 0.5 mm to 1 mm, and / or the dispersion pattern of each entrance surface (14c) and each exit surface (14e) has a pattern depth of 0.1 mm to 0.5 mm and a pattern period of 0.2 mm to 1 mm.

10. The light bar according to any one of the preceding claims, wherein the angle between the entrance surface (14c) and the deflection surface (14r) is 45 degrees ±10 degrees, preferentially ±5 degrees.

11. The light bar according to any one of claims 1 to 10, further comprising arches (14a) arranged along the light bar (40) between the optical portions, preferably the light bar (40) further comprising at least one centering piece abutting against at least one of the arches (14a).

12. The light bar according to any one of the preceding claims, further comprising a pin (113), preferably a headed pin.

13. The light bar according to any one of the preceding claims, wherein the entrance surface (14c) of at least one of the optical parts is perpendicular to a light emission direction of the plurality of light sources (15).

14. The light bar according to any one of claims 1 to 13, wherein the entrance surface (14c) of at least one of the optical portions is arranged such that no radiation from the plurality of light sources (15) directly approaches the diffuser (12).

15. A vehicle steering wheel comprising a light bar (40) according to any one of the preceding claims.

16. Motor vehicle equipped with a vehicle steering wheel (1) according to claim 15.

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