EP0549423B1 - Lens for signalling optical device equipped with pseudo-catadioptric elements - Google Patents

Abstract

The invention relates to a lens (G) for at least one signalling light, in particular for a motor vehicle, comprising a plurality of pseudo-catadioptric elements, having the appearance of catadioptric needles without acting as such. At least some of the pseudo-catadioptric elements (20) have a conical end (26) on the inner side of the lens. The making of a mould for bulk manufacturing of such a lens is thereby greatly facilitated. <IMAGE>

Description

The present invention relates generally to signaling lights, in particular for motor vehicles, of which a window (or globe or even indicator) is equipped with pseudo-catadioptric elements and if necessary catadioptric elements.

In all of the following description, the term "pseudo-reflector" or "pseudo-retro-reflective element" means an optical element which has an aspect close to that of a true reflector, without having the function of retro-reflection.

Referring firstly to FIG. 1, a conventional catadioptric element or "needle" 10 formed, for example in a traffic light glass, consists of an essentially planar face of light entry and exit, situated on the side outside of the glass, and of three flat surfaces 14a-14c arranged in a tri-rectangle trihedron, located on the inside of the glass and intended to retro-reflect, by total reflection on each of the faces, the incident light oriented in a direction close to the longitudinal axis of the element.

For this retro-reflection to be properly carried out, the angle α defined by the faces of the trihedron two by two is equal to 90 °, and these faces tangent a cone whose half-angle at the top β is equal to 35 ° 15 ' .

A well-known pseudo-catadioptric element 20 is represented in FIG. 2. The faces 24a-24c of the trihedron form an angle α ′ different from 90 °, and for example of the order of 92 °, and the half-angle at the top β 'is worth for example 36 ° 25', so that the retro-reflection function is no longer ensured, while the element retains, when the fire is out, an aspect completely similar to that of a real catadioptric element. Such an element is known from FR-A-2 589 983.

Another known solution for producing a pseudo-reflector consists in preserving the geometry of the retro-reflecting element in FIG. 1, by etching the faces 14a-14c to remove the total reflection thereon.

These two known solutions have a first drawback, according to which the pseudo-catadioptric elements are at least as long and costly to produce as catadioptric elements, while they have no optical function to fulfill.

Furthermore, the pseudo-catadioptric elements described above have the drawback of not letting the light emitted from the interior of the light pass, the latter therefore not being able to participate in the signaling beam to be formed.

A known solution to this problem of loss of light is shown in FIG. 3. It consists in providing, on the inside of the glass G of the light, an intermediate screen E which comprises lenses L or the like intended to concentrate the majority of the light coming from the source or from a reflector in the direction of zones 30 of the ice which are not treated as pseudo-reflectors, and which are capable of letting the light pass.

This known solution is again disadvantageous in that it causes an additional cost of the fire, and in that it becomes more difficult to meet the regulations in terms of photometry.

The first object of the present invention is to provide a lens comprising pseudo-catadioptric elements which are extremely simple and economical to produce.

To this end, it relates to a lens for at least one signaling light, in particular for a motor vehicle, comprising, in at least one zone, a plurality of pseudo-catadioptric elements characterized in that the pseudo-catadioptric elements each have a conical end on the inside of the glass, as described in the independent claims.

In the case where the apex angle of at least one group of pseudo-catadioptric elements is between approximately 110 and 165 °, preferably between 130 and 150 °, these elements let the incident light pass through said inner side of ice.

On the contrary, if the angle at the top of at least one group of pseudo-catadioptric elements is less than about 110 °, these elements at least partially obscure the light incident on said inner side of the glass.

In order to adjust the scattering of light passing through passing pseudo-catadioptric elements, the orientation of the axes of the conical ends can be varied from one pseudo-catadioptric element to another.

Preferably, at least one group of pseudo-catadioptric elements is arranged in an elongated strip comprising one or more rows of said elements. And more preferably, the lens comprises a plurality of elongated parallel pseudo-catadioptric bands each comprising one or more rows of pseudo-catadioptric elements alternating with a plurality of elongated bands for processing a light beam.

In this case, said elongated strips for processing a light beam each advantageously comprise a plurality of light scattering elements, and these elements preferably have an identical pitch or an integral multiple of a pitch of the pseudo-catadioptric elements said bands.

Furthermore, each conical end of a retro-reflecting element may be provided on a rib extending from the inside of the glass over at least part of the width of each pseudo-retro-reflecting strip.

In particular in the case of a lens for an optical unit incorporating different signaling functions, this lens may comprise side by side at least a first region having a plurality of pseudo-catadioptric bands alternating with a plurality of elongated bands of treatment of a light beam and a second region having a plurality of retro-reflecting strips each comprising one or more rows of retro-reflecting elements and situated in alignment with said pseudo-retro-reflecting strips, alternating with a plurality of elongated treatment strips a light beam to emit.

The invention also relates to a signaling device for a motor vehicle, incorporating at least one signaling function, characterized in that it comprises a window as defined above.

• la figure 1 est une vue schématique en élévation d'un élément catadioptrique classique,
• la figure 2 est une vue schématique en élévation d'un élément pseudo-cadatrodiptrique classique,
• la figure 3 est une vue en coupe schématique à travers une glace et un écran intermédiaire de la technique antérieure,
• la figure 4 est une vue de face d'un ensemble de pseudo-catadioptres selon la présente invention,
• la figure 5 est est une vue en coupe selon la ligne V-V de la figure 4,
• la figure 6 est une vue de face partielle d'une première forme de réalisation d'une glace équipée de zones pseudo-catadioptriques selon l'invention,
• la figure 7 est une vue en coupe selon la ligne VII-VII de la figure 6,
• la figure 8 est une vue de face partielle d'une deuxième forme de réalisation d'une glace équipée de zones pseudo-catadioptriques selon l'invention,
• la figure 9 est une vue en coupe selon la ligne IX-IX de la figure 8, et
• la figure 10 est une vue de face partielle d'une glace équipée de zones catadioptriques dans certaines régions et de zones pseudo-catadioptriques dans d'autres régions.

Other aspects, aims and advantages of the present invention will appear better on reading the following detailed description of a preferred embodiment thereof, given by way of non-limiting example and made with reference to the accompanying drawings, on which ones :

• FIG. 1 is a schematic elevation view of a conventional retro-reflecting element,
• FIG. 2 is a schematic elevation view of a conventional pseudo-cadatrodiptric element,
• FIG. 3 is a schematic sectional view through a glass and an intermediate screen of the prior art,
• FIG. 4 is a front view of a set of pseudo-reflectors according to the present invention,
• FIG. 5 is a sectional view along the line VV of FIG. 4,
• FIG. 6 is a partial front view of a first embodiment of a lens fitted with pseudo-catadioptric zones according to the invention,
• FIG. 7 is a sectional view along line VII-VII of FIG. 6,
• FIG. 8 is a partial front view of a second embodiment of a lens fitted with pseudo-catadioptric zones according to the invention,
• FIG. 9 is a sectional view along the line IX-IX of FIG. 8, and
• FIG. 10 is a partial front view of a window fitted with retro-reflecting zones in certain regions and pseudo-retro-reflecting zones in other regions.

It will be noted at the outset that, from one figure to another, identical or similar elements or parts have been designated by the same reference signs.

Referring to Figures 4 and 5, there is shown a pseudo-catadioptric zone of a signal light lens G which comprises a set of pseudo-catadioptric elements 20 of hexagonal contours (these contours not being materialized in practice , the glass being in one piece) and whose geometric arrangement is that of a honeycomb.

According to an essential aspect of the invention, the bottom face of each element, on the inner side of the crystal, is defined by a cone, designated by the reference 26. In a basic embodiment, the axis of the cone s 'extends in the longitudinal direction of the element 20, advantageously parallel to the longitudinal direction of the vehicle.

It was unexpectedly found that such a cone, although it has a geometry very different from a trihedron, gave the element when the fire is extinguished an appearance quite similar to that of a true catadioptric element .

In addition, a pseudo-catadioptric element according to the invention proves to be extremely easy and economical to produce, since it suffices to form in the mold which will be used to make the blind hole glass with a tapered drill, in the appropriate locations.

Another advantage of the invention lies in the fact that a cadiatopter thus defined, by an appropriate choice of the angle at the top of the cone, can let light through. More specifically, a satisfactory passage of light is obtained for an apex angle of between approximately 110 and 165 °, preferably between approximately 130 and 150 °.

In addition, according to an advantageous aspect of the invention, it is possible to modify the orientation of the axis of each cone of pseudo-catadioptric element in order to effect a horizontal and / or vertical distribution of the light coming from the source in the light beam, thanks to the induced variation of the orientation of the refracted rays.

Of course, it is possible in certain cases to use pseudo-catadioptric elements according to the invention which let in little or no light. In this case, vertex angles between about 70 ° and 110 ° are chosen for the cones; the light is almost completely obscured for apex angles less than or equal to about 78 °.

More generally, an appropriate choice of the angle at the top of the cones of the pseudo-catadioptric elements, or even the use in the same lens of pseudo-catadioptric elements whose apex angles have different values, make it possible, if necessary "work" the photometry of a beam formed by intervening on the incident rays on the pseudo-catadioptric regions.

Figures 6 and 7 partially illustrate a closing glass organized in relatively narrow bands alternately comprising pseudo-catadioptric elements (zones Z1) and elements for diffusing the light emitted by the source, or in certain cases without optical role, for example with parallel faces (zones Z2).

In the present example, each strip Z1 has two horizontal rows of pseudo-catadioptric elements 20 staggered. The bands Z2 comprise toric elements 50, that is to say cylindrical ridges of curved vertical profile, allowing the diffusion of the light emitted by the source horizontally and vertically.

In addition, it can be seen in FIG. 6 that the bands Z1 and Z2 have approximately the same width, and that each diffusion toroid 50 has a width equal to the width of an individual pseudo-catadioptric element. It is further observed in FIG. 7 that the angle at the top of the cones is approximately 120 °, that is to say that they allow a very large proportion of the light received from the source to pass through, also performing a dispersion of it.

The outer face of the glass G is smooth to comply with the regulations.

It will be noted that the diffusion elements 50 can take any suitable form such as cylindrical, toric, spherical, prismatic, etc.

Figures 8 and 9 illustrate another concrete embodiment of the invention. Here again there are zones Z1 with pseudo-catadioptric elements and zones Z2 for light scattering. Each zone in band Z1 comprises a single row of pseudo-catadioptric elements 20 whose individual (intangible) contours are generally rectangular. The elements 50 are again toroids, and have a width twice the width of the individual pseudo-catadioptric elements. Finally we observe that the width of the Z1 bands is slightly less than that of the Z2 bands.

In general, it is preferred that the pitch of the diffusion elements 50 along the length of the strips alternating either identical or an integer multiple of the pitch of the pseudo-catadioptric elements.

FIG. 10 shows part of a window G of a block of rear vehicle signaling lights which comprises several regions R1 to R5 assigned for example to the following five light functions, respectively: reversing light, flashing light, rear fog light, position light and brake light. Of course, suitable light sources, in combination where appropriate with reflectors or lenses, are provided in association with each region.

The regions R1, R2, R3 and R5 are produced in the spirit of FIGS. 6 to 9, with bands Z1 constituted by pseudo-catadioptric elements 20 according to the invention in alternation with bands Z2 composed of diffusion elements 50 light.

The region R4 corresponding to the position light comprises bands Z3 composed of true retro-reflecting elements 10, alternating with bands Z2 comprising elements 50 for scattering light.

The zones Z2 of the three regions R3 to R5 preferably all have the same width (which may also be the case of the zones Z2 of the regions R1 and R2), while the zones Z1 and Z3 also all have the same width. This gives a great homogeneity of appearance to the glass G in particular in its lower part, the zones Z3 of real retro-reflectors having practically the same appearance, when all the light functions are off, as the zones Z1 of pseudo-retro-reflectors.

As indicated above, the production of a mold part intended for manufacturing an ice cream according to the invention in series calls for the production of blind holes with a conical bottom for the pseudo-catadioptric elements. This being so, in order to obtain a transition as clear and regular as possible between the zones Z1 of pseudo-reflectors and the neighboring zones Z2, a groove of rectangular section is made beforehand at the bottom of which the conical bottoms will then be made . In addition, the presence of such a groove makes it possible to avoid direct intersections between the cones of the pseudo-catadioptric elements and the neighboring toric elements, which could cause it to be impossible to demold in highly inclined parts of the ice. FIG. 8 in particular shows the straight lines D of transition between the zones Z1 and Z2, which correspond to the edges of the groove, and FIG. 9 shows the ribs of rectangular section N corresponding to the grooves of the mold.

Of course, the same lens produced according to the invention may include pseudo-catadioptric elements of different designs in terms of angles at the top of the cones and of orientation of these cones. This is how certain pseudo-catadioptric elements allowing light to pass can coexist with other pseudo-catadioptric elements not allowing light to pass through.

Claims (12)

1. A glass (G) for at least one signalling lamp, in particular for a motor vehicle, comprising, in at least one zone (Z1) a plurality of pseudo-catadioptric elements (20), characterised in that the pseudo-catadioptric elements each have a conical end (26) on the inside face of the glass.
2. A glass according to claim 1, characterised in that the angle at the apex of at least one group of pseudo-catadioptric elements (20) lies in the range of about 110° to about 165°, preferably in the range of 130° to 150°, thereby allowing the incident light to pass on said inside face of the glass.
3. A glass according to any of claims 1 or 2, characterised in that the angle at the apex of at least one group of pseudo-catadioptric elements (20) is less than about 110°, so as to obscure at least part of the incident light on said inside face of the glass.
4. A glass according to any of claims 1 to 3, characterised in that the angle at the apex and/or the orientations of the axes of the conical ends vary from one pseudo-catadioptric element(20) to another.
5. A glass according to any of claims 1 to 4, characterised in that at least one group of pseudo-catadioptric elements (20) is disposed in an elongate strip (Z1) including one or more rows of said elements.
6. A glass according to claim 5, characterised in that it comprises a plurality of pseudo-catadioptric elongate parallel strips (Z1) each including one or more rows of pseudo-catadioptric elements, alternating with a plurality of elongate strips (Z2) for processing a light beam.
7. A glass according to claim 6, characterised in that each of said elongate strips (Z2) for processing a light beam includes a plurality of light diffusion elements (50).
8. A glass according to claim 7, characterised in that the pitch of said light diffusion elements (50) in the long direction of the elongate strips is identical to the pitch of the pseudo-catadioptric elements of said strips, or to an integer multiple thereof.
9. A glass according to claim 5, characterised in that each conical end (26) of a pseudo-catadioptric element is provided on a rib (N) that extends over the inside face of the glass for at least a fraction of the width of each pseudo-catadioptric strip (Z1).
10. A glass according to claim 6, characterised in that it includes side-by-side, at least one first region (R3, R5) having a plurality of pseudo-catadioptric strips (Z1) alternating with a plurality of elongate strips (Z2) for processing a light beam, and a second region (R4) having a plurality of catadioptric strips (Z3) each including one or more rows of catadioptric elements (10) and situated in line with said pseudo-catadioptric strips (Z1), alternating with a plurality of elongate strips (Z2) for processing a light beam to be emitted.
11. A glass according to claim 10, characterised in that the first (R3, R5) and second (R4) regions correspond to two different light functions of a signalling lamp block.
12. A motor vehicle signalling device including at least one signalling function, characterised in that it comprises a glass (G) according to any one of claims 1 to 11.

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