WO2012095578A1

WO2012095578A1 - Lighting device having a light guide comprising an attachment means and reflecting light downward, and related mounting

Info

Publication number: WO2012095578A1
Application number: PCT/FR2011/053115
Authority: WO
Inventors: Rodolphe Peron; Pascal Bouret
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2011-01-10
Filing date: 2011-12-20
Publication date: 2012-07-19
Also published as: BR112013016709A2; EP2663804B1; BR112013016709B1; EP2663804A1; FR2970319B1; FR2970319A1; ES2501842T3; CN103314253B; CN103314253A

Abstract

The invention relates to a lighting device (D) including at least one elongate light guide (G) comprising two opposite ends (E1, E2), each of which have a first attachment means (MF1) capable of enabling the attachment thereof to a mounting, and connected via a main portion (PP) suitable for guiding light and comprising an outer surface (FE) having, on part of a rear portion (PR), a reflection means (MR) suitable for reflecting light to a front portion (PV). Said device (D) also includes at least one second attachment means (MF2) which is secured to a selected location on the main portion (PP) on the rear side (PR) thereof and just over the reflection means (MR) so as to reflect light downward, and which is securable onto the mounting.

Description

LIGHT-GUIDING LIGHT-GUIDING DEVICE WITH LIGHT-REFLECTING FIXATION, AND SUPPORT THEREFOR

The invention relates to light devices comprising at least one light guide.

As known to those skilled in the art, certain light devices comprise at least one elongate light guide having two opposite ends connected by a main part.

Each of these two ends is generally provided with a first fixing means intended to allow the fixing of the light guide to a support, such as for example and not limited to a vehicle optical block housing, possibly of automotive type. Moreover, at least one of the two ends is generally placed in front of a light source which may, for example, comprise at least one light emitting diode (or LED).

Note that here is meant by "optical block" both a projector and a fire.

The main portion of the light guide is arranged to guide the light from the light sources and has an outer surface which is provided on a portion of a rear portion with reflection means which are adapted to reflect light towards a light source. front part.

As long as the light guide is not too long, typically less than about 25 cm, its first two attachment means are sufficient to effectively secure it to its support. But, when its length becomes important, it is necessary to add at least a second fastening means to its main part or to provide dedicated retaining means, reported and including clipping pins.

Such pins appear in transparency and / or induce areas of shadows, which affects the style effect and can be considered a defect or a low-end level indicator.

Moreover, each second fixing means is currently secured to the main part of the light guide, on the side of its rear part and just below the reflection means. Alas, such positioning induces two drawbacks that are detrimental to the style effect and may be considered as a defect or a low-end level indicator. Indeed, when the light guide is not illuminated, the natural light that enters a second attachment means tends to reflect forward and slightly upward, which not only makes it apparent for a person which is situated in front of him and whose eyes are placed at a higher height than hers, but also induces a magnifying effect of its base by a magnifying effect. On the other hand, when the light guide is illuminated, a portion of the light propagating in the main part of the light guide enters the second fixing means, which not only causes a decrease in the number of photons participating in the function. lighting but also induces a dark area at its base, observable by transparency.

The object of the invention is therefore to improve the situation, and more precisely to prevent a second means of fixing a light guide from being observable by a person who is situated in front of him and whose eyes are placed in front of him. a height higher than his.

It proposes for this purpose a light device comprising at least one longiline light guide comprising:

- two opposite ends and each provided with a first fastening means adapted to allow its attachment to a support,

a main part connecting the two ends, adapted to guide light and having an outer face provided on a portion of a rear portion of reflecting means adapted to reflect light towards a front part, and

at least one second fixing means, on the one hand, secured to a chosen location of the main part of the light guide, on the side of its rear part and just above the reflection means so as to reflect light down, and, secondly, own to be secured to the support.

The light device according to the invention may comprise other features that can be taken separately or in combination, including:

each second fixing means can be arranged in the form of a tab;

the tab can project beyond the back of the main part of the light guide;

each second fixing means may be an integral part of the light guide;

each first fixing means may be an integral part of the light guide;

- The reflection means may be defined on a substantially flat portion of the rear portion of the main portion of the light guide;

the reflection means can be arranged in the form of a three-dimensional (or 3D) relief;

the three-dimensional relief may consist of grooves substantially parallel to each other and substantially perpendicular to the general direction of the light guide. For example, the grooves may have a triangular section;

it may comprise at least one light source in front of at least one of the two ends of the light guide;

each light source may comprise at least one light emitting diode (or LED).

The invention also proposes a support comprising at least one light device of the type of that presented above. Such a support may, for example, constitute a vehicle optical block housing, possibly of automotive type.

The invention also proposes a vehicle optical unit, possibly of automotive type, and comprising a support of the type of that presented above.

Other features and advantages of the invention will appear on examining the detailed description below, and the accompanying drawings (obtained in CAD / DAO, hence the apparently discontinuous character of certain lines), on which ones :

FIG. 1 schematically illustrates, in a perspective view of the front side, an example of an optical unit equipped with an exemplary embodiment of a light device according to the invention,

FIG. 2 schematically illustrates, in a perspective view of the front side, the light device of FIG. 1, before it is secured to the housing of the optical unit, and

FIG. 3 schematically illustrates, in a view both in section and in perspective of the rear side, a portion of the light guide of the light device of FIG. 2.

The attached drawings may not only serve to complete the invention, but also contribute to its definition, if any.

The object of the invention is to propose a light device (D) intended to be secured to a support (S) in order to fulfill a photometric function therein.

In the following, we consider, by way of non-limiting example, that the support (S) is a housing of a vehicle optical block (BO), possibly of automotive type. But, the invention is not limited to this type of support. It concerns indeed any type of support to which can be secured at least one light guide device (s) of light, and which belongs to the field of lighting or the field of signaling. Thus, a support (S) can be secured to a housing or to an optical block reflector, for example.

Park elsewhere, it is considered in the following, by way of non-limiting example, the optical unit (BO) is intended to be installed in the front of a vehicle, possibly of the automotive type. But, the invention is not limited to this type of implantation. It also relates to certain optical units intended to be installed at the rear of a vehicle, possibly of the automotive type.

In addition, it is considered in the following, by way of non-limiting example, that the light device (D) is intended to provide a function called DRL (for "Daytime running Light (Gold Lamp)" - light signaling automatically when the vehicle starts to move forward). But, the invention is not not limited to this application when it concerns a vehicle. Thus, it also relates, and in particular, the position light function (or night light or lantern) or the direction indicator function.

It will be noted that hereinafter "front part" is understood to mean a part which is oriented towards the outside of the support (in this case an optical block housing), and by "rear part" a part which is oriented towards the inside. of the support. It will also be noted hereinafter that "lower part" is understood to mean a part which is generally oriented downwards (BA), that is to say oriented towards the road, and by "upper part" a part which is generally upward (H), that is to say opposite of the road.

FIG. 1 diagrammatically illustrates an exemplary embodiment, not limiting, of an optical unit BO of a motor vehicle comprising a housing S defining a support to which is secured, here, a single light device D, according to the invention.

It is recalled that a vehicle OB optical unit generally comprises a housing S to which are attached a mask, a possible RF reflector, and an ice that is placed in front of the RF reflector and possibly in front of the mask. The housing S defines at least one open cavity which houses the mask, the optional RF reflector and at least one light source, such as for example a bulb or a lamp or a light-emitting diode or the light device D.

In the nonlimiting example illustrated in Figure 1, the device (light) D is secured to the housing S in an upper peripheral portion.

As illustrated in FIGS. 1 and 2, a light device D according to the invention comprises at least one light guide G. It will be noted that in FIGS. 1 and 2 the device D comprises only one light guide G. But, it could have several (at least two) light guides G.

The light guide G is of elongated type, possibly curvilinear (as illustrated without limitation), and has two ends E1 and E2 opposite and interconnected by a main part PP.

It will be noted that the light guide G can for example be made by molding in a synthetic material, for example in PC (polycarbonate) or PMMA. Moreover, the light guide G may be optionally colored in the mass.

Each end E1 or E2 of the light guide G is provided, on an outer face FE, a first fixing means MF1 which is arranged to allow the fixing of the light guide G to the support S (here the housing).

It should be noted that each first fixing means MF1 is preferably an integral part of the light guide G, in particular when the latter (G) is produced by molding.

It will also be noted that the device D may optionally comprise at least one light source (SL) in front of at least one of the two ends E 1 and E 2 of its light guide G. It will be noted that in the nonlimiting example illustrated on FIG. 2, the device D comprises two light sources SL respectively in front of its two ends E1 and E2. This makes it possible to have a good homogeneity of illumination in the entirety of the principal part PP of the light guide G.

For example, each light source SL may comprise at least one light emitting diode (or LED). Note that each light emitting diode may be arranged to emit a white light (especially for a front optical unit) or a colored light (for example red, in particular for a rear optical unit).

When using light-emitting diodes, it is advantageous that they be mounted on a support plate intended to allow at least their control and their power supply. This support plate may for example be a printed circuit board, of the PCB type ("Printed Circuit Board"), rigid or flexible ("type" Flex ").

Each light-emitting diode may be coupled to an end E1 or E2 of the light guide G either directly, for example by gluing or by embedding in a hole defined in its injection end face, or indirectly, for example via the plate of FIG. support.

Each first fixing means MF1 of an end E1 or E2 may, for example, be arranged in the form of a fixing lug intended to be secured to the housing S. This fastening can be done by clipping in a corresponding clipping means of the housing S (for example defined in a housing), or by screwing. In the latter case (screwing), the bracket MF1 may include an opening possibly threaded for the passage of a screw.

In the non-limiting example illustrated in FIG. 2, the first attachment means MF1 of the first E1 and second E2 ends are oriented downwards and slightly towards the front. But, the first MF1 fixing means may have other orientations (possibly substantially different from each other) as long as they ensure their invisibility for a person who is located in front of the optical block BO.

The main portion PP of the light guide G is arranged to guide (in its mass) the light that is generated by each light source SL.

In the nonlimiting example illustrated in FIG. 3, the light guide G has a section of generally circular shape. But this is not obligatory. This section could indeed be rectangular or square or pentagonal or hexagonal, for example.

The main part PP of the light guide G has, on its outer face FE, in a portion of its rear portion PR, reflection means MR which are arranged to reflect light from the ends E1 and E2 towards its front part. PV, to ensure the photometric function of the device D.

As illustrated non-limitatively in FIGS. 2 and 3, the rear portion PR of the main portion PP of the light guide G may comprise a substantially flat portion PN in which the reflection means MR are defined which are intended to promote the reflection of the light towards the front part PV. As illustrated without limitation in FIG. 3, these reflection means MR can be arranged in the form of a three-dimensional (or 3D) relief which optimizes the transfer towards the front part PV of the light guide G of the light which is propagated to inside the latter (G).

Here, the term "light transfer" is understood to mean a deflection caused by a reflection or a refraction, or even a diffraction, at the level of a matter-air or air-material interface, and therefore at the 3D MR relief level. (internal side).

As illustrated nonlimitingly in FIG. 3, the 3D relief MR may for example consist of grooves (or ribs, which amounts to the same) which are, on the one hand, substantially parallel to each other (and therefore here substantially perpendicular to the general direction of the light guide G. It is important to note that because of the possible curvatures that a light guide G presents, the grooves (or ribs) MR may no longer be locally parallel to each other (in particular in the zones of Curvature) Parallelism must be understood here as a general tendency.

For example, the grooves (or ribs) MR may have a section of substantially triangular shape (possibly isosceles), or more generally in the form of a sawtooth.

It should be noted that the 3D relief MR does not necessarily consist of lines (grooves or ribs or striations). It may indeed consist of three-dimensional (3D) patterns, possibly diffracting, or be arranged in the form of a diffraction grating.

Moreover, and as illustrated in FIG. 3, the main part PP of the light guide G comprises at least a second fixing means MF2 which is secured at a chosen place of its rear part PR, just above the reflection means. MR (and thus here just above the flat portion PN), to reflect down BA light that has penetrated into its mass (see the white arrows materializing multiple reflections).

The light coming from a second fixing means MF2 is now reflected downwards BA (and no longer upwards as in the prior art), at the interface between this second fixing means MF2 and the G light guide, it always induces an image of the base of the second attachment means MF2. But, this image can now be observed only by a person who is located in front of the optical block BO and whose eyes OP are placed at a height strictly lower than the second attachment means MF2. In other words, this image is invisible for a person who is located in front of the optical block BO and whose eyes OP are placed at a height greater than that of the second attachment means MF2, which is almost always the case. an observer who does not perform a repair. Thus, thanks to the invention, a person normally positioned in front of the device D no longer perceives any visible visual defect, whether it is illuminated or not.

Each second fixing means MF2 is intended to be secured to the housing S, and may, for example and as illustrated without limitation, be in the form of a bracket. Preferably, this fixing lug MF2 projects beyond the rear part PR of the main part PP of the light guide G. Moreover, this securing can be done by clipping into a corresponding clipping means of the housing S (by example defined in a housing), or by screwing (as illustrated without limitation). In the latter case (screwing), each second attachment means MF2 (here a fixing lug) may comprise an opening OV possibly threaded for the passage of a screw.

In the nonlimiting example illustrated in FIG. 2, the main part PP of the light guide G is provided with two second fixing means MF2 in two chosen locations, so as to further improve the fastening to the box S. However, could have only one, or more than two.

It will be noted that each second attachment means MF2 preferably forms an integral part of the light guide G, in particular when the latter (G) is produced by molding.

The invention is not limited to the embodiments of light device, support and optical block described above, only by way of example, but it encompasses all variants that may be considered by those skilled in the art in the scope of the claims below.

Claims

1. Light device (D) comprising at least one elongate light guide (G) having two opposite ends (E1, E2), each provided with a first fixing means (MF1) adapted to allow its attachment to a support (S) and connected by a main portion (PP) adapted to guide light and having an outer face (FE) provided on a portion of a rear portion (PR) of reflection means (MR) adapted to reflect light towards a front part (PV), characterized in that it comprises at least a second fixing means (MF2) secured to a chosen location of said main part (PP) on the side of its rear part (PR) and just above above said reflection means (MR) so as to reflect light downwards, and adapted to be secured to said support (S).

2. Device according to claim 1, characterized in that each second fixing means (MF2) is arranged in the form of a tab.

3. Device according to claim 2, characterized in that said tab (MF2) projects beyond said rear portion (PR) of the main part (PP) of said light guide (G).

4. Device according to one of claims 1 to 3, characterized in that each second fixing means (MF2) is an integral part of said light guide (G).

5. Device according to one of claims 1 to 4, characterized in that each first fixing means (MF1) is an integral part of said light guide (G).

6. Device according to one of claims 1 to 5, characterized in that said reflection means (MR) are defined on a substantially flat portion (PN) of the rear portion (PR) of the main portion (PP) of said guide of light (G).

7. Device according to one of claims 1 to 6, characterized in that said reflection means (MR) are arranged in the form of a three-dimensional relief.

8. Device according to claim 7, characterized in that said three-dimensional relief (MR) consists of grooves substantially parallel to each other and substantially perpendicular to a general direction of said light guide (G).

9. Device according to one of claims 1 to 8, characterized in that it comprises at least one light source (SL) in front of at least one of the two ends of said light guide (G).

10. Device according to claim 9, characterized in that each light source (SL) comprises at least one light emitting diode.

1 1. Support (S), characterized in that it comprises at least one light device (D) according to one of the preceding claims.

12. Support according to claim 1 1, characterized in that it constitutes a vehicle optical block housing (BO).

13. Optical block (BO) of a vehicle, characterized in that it comprises a support (S) according to one of claims 1 1 and 12.