EP1496304A1 - Signal lamp for vehicle - Google Patents

Abstract

The light has a screen (E) located in front of a lamp and an exit glass, and made up of transparent or translucent material. The screen has a set of patterns (3) ensuring a spatial distribution of the light energy in localized zones (4) at an exit of the screen by direct transmission and/or internal reflection, while transferring the light energy entering the screen. An independent claim is also included for a motor vehicle equipped with a signal light.

Description

The invention relates to a lighting device and / or vehicle signaling, and more particularly at a traffic light for vehicles with at least one compartment equipped with a lamp, with an optical system to form a beam, a screen in front of the lamp and an ice cream.

Traffic lights have been made for a long time with Filament lamps as light sources that give a bright spot keep on going. New sources of light have appeared such as diodes electroluminescent devices (LEDs) which enable the functions of signaling by concentrating light in small areas. The result is a different appearance, which can be described as "discreet" because there is formation of separate luminous points. This concentration of light in points is also favorable to a better perception of the signal luminous.

Light emitting diodes ("LEDs") being relatively costly, we sought to make traffic lights using conventional light sources with a "discreet" appearance bright spots, also called "pixels", similar to the one obtained with leds.

EP 1 149 732 proposes a traffic light with a reflector associated with an optical system composed of lenses, and a pierced opaque screen holes through which the different beams produced by the lenses to give the appearance of mini illuminated beaches. Such a montage is relatively delicate: a not insignificant part of light does not pass in holes and is absorbed by the screen, especially because of the tolerances of manufacturing. The energy efficiency of such a system is relatively low.

The object of the invention is, above all, to provide a signaling light to lamp that allows to obtain a pixel appearance with a good performance Energy. It is desirable, furthermore, that the signaling light remains simple and economical manufacturing.

According to the invention, a vehicle signaling light of the kind defined above, is characterized in that the screen is made of a material transparent or translucent, and includes a set of patterns allowing to provide at the output of said screen, by direct transmission and / or by reflection internally, a spatial distribution of light energy in localized, in particular almost punctual, by transferring the essential the light energy entering the screen. Preferably there is a source bright type incandescent lamp. However, it is also possible to replace them with one or more light-emitting diodes (Led). For example, "most of the light energy" is understood to mean the makes the screen work optically as if it were, schematically, a flat screen and neutral, so we recover the screen output almost any light energy.

Localized areas of distribution of light energy have the appearance of pixels or elementary points. So we have lit areas that can be clearly separated and spaced from each other.

The set of patterns is advantageously constituted by the repetition according to a determined geometrical arrangement, for example hexagonal (in honeycomb) or matrix, of an elementary pattern. Of preferably, the patterns are joined, to have the maximum optical efficiency, but it is also possible to provide zones between the patterns that do not have the optical properties of said patterns.

The elementary pattern advantageously has the shape of a funnel bounded, on the exit side, by a substantially frustoconical axis of rotation parallel to that of the light beam, which connected by its small base to a coaxial cylindrical pin projecting forwards, this funnel being delimited on the side of the entrance by a cavity of revolution to stepped meridian, preferably substantially at right angles, favoring the total reflection.

The revolution cavity may comprise a central portion cylindrical whose bottom is orthogonal to the beam direction to allow a direct transmission, the open end towards the rear of this cavity being followed by a first annular surface orthogonal to the beam direction then by a cylindrical surface of larger diameter than the central part, leading to the back of the screen.

The fire may include a style screen pierced with holes specific to receive the ends of the pawns, this style screen hiding the patterns that are find behind him. Preferably the ends of the pions protrude the style screen.

The front end of a pin is advantageously provided with least one motif, of the torus type, capable of ensuring the spatial distribution of the outgoing light.

Preferably, the traffic light comprises a system collimator capable of forming a pseudo-collimated luminous flux, that is to say parallel or substantially parallel, collected by the rear portion of the screen. The collimator system preferably comprises a Fresnel lens, or variant a parabolic reflector.

The material used for the screen may be PMMA (polymethyl methacrylate) or PC (polycarbonate) according to thermal constraints.

The screen can have a circular or rectangular shape depending of the desired style. It can be flat or three-dimensional, especially with sliding of each elementary pattern parallel to the direction of the beam bright to obtain apparent outlets, corresponding to the ends cylindrical pins, distributed in space for example according to a surface parallel to the exit ice.

The inclination of the generatrices of the frustoconical surface of a motive is chosen to ensure total reflection.

The ratio of the input diameter of a pattern to the output diameter is advantageously of the order of three to five, preferably of the order of four. The input diameter of a pattern may be of the order of 15 to 25 mm, in particular 20 mm while the output diameter may be of the order of 3 to 10 mm, especially 5 mm.

It is possible by using this principle via a subtractive synthesis to improve the red appearance of a signaling function, such as a reversing light or direction indicator, when off. The red exit ice has pink areas of reduced area corresponding to the usable area illuminated by the exit of a screen pattern.

Fig.1 est un schéma en coupe verticale axiale d'un compartiment de feu de signalisation selon l'invention.

Fig.2 montre, semblablement à Fig.1, une variante de réalisation.

Fig.3 montre le feu de Fig.1 avec une glace de sortie prévue pour améliorer l'aspect rouge.

Fig.4 est une vue en perspective de l'avant d'un motif de l'écran, à plus grande échelle.

Fig.5 est une vue en perspective éclatée du motif de Fig.4.

Fig.6 est un schéma illustrant le trajet des rayons lumineux dans un motif de l'écran, à plus grande échelle.

Fig.7 est une vue en perspective de l'avant de l'écran.

Fig.8 est une vue en perspective, sous un autre angle, de l'avant de l'écran muni d'un écran de style.

Fig.9 est une vue en perspective de l'arrière d'une version plane de l'écran, et

Fig.10 est une vue en perspective de l'arrière d'une version en trois dimensions de l'écran.

The invention consists, apart from the arrangements described above, in a certain number of other arrangements which will be more explicitly discussed below with regard to exemplary embodiments described in detail with reference to the appended drawings, but which are in no way limiting. On these drawings:

Fig.1 is a diagram in vertical axial section of a traffic light compartment according to the invention.

Fig.2 shows, similarly to Fig.1, an alternative embodiment.

Fig.3 shows the fire of Fig.1 with an exit window provided to improve the red appearance.

Fig.4 is a perspective view from the front of a screen pattern, on a larger scale.

Fig.5 is an exploded perspective view of the pattern of Fig.4.

Fig.6 is a diagram illustrating the path of light rays in a pattern of the screen, on a larger scale.

Fig. 7 is a perspective view of the front of the screen.

Fig.8 is a perspective view, from another angle, of the front of the screen provided with a style screen.

Fig.9 is a perspective view of the rear of a flat version of the screen, and

Fig. 10 is a perspective view of the back of a three-dimensional version of the screen.

Referring to Fig.1 of the drawings, one can see a fire signaling A for a vehicle comprising at least one equipped compartment C of a lamp L, with an optical system S to form a beam, a screen E in front of the lamp and an exit glass G.

The term "before" should be understood by considering the meaning of spread of light. Thus, for a traffic light located at the rear of the vehicle and lighting backwards, the screen E while being in front of the lamp L according to the direction of propagation of the light, will be behind this lamp following the normal direction of progression of the vehicle. In the case of a fire At the front of the vehicle, screen E is in front of the vehicle. L lamp regardless of the meaning considered.

The output ice G is generally transparent. Although this element is called "ice" it can be made of a transparent material or translucent other than glass.

According to the embodiment of FIG. 1, the optical system S consists of a Fresnel lens 1 which collects the luminous flux of the source L following a solid angle of maximum amplitude, including in the axial direction. The midpoint of the filament is substantially at the focus of the lens 1. The Fresnel lens 1 outputs a beam pseudo-collimated beam 2 such as 2a, 2b parallel or substantially parallel. The Fresnel lens 1, or an equivalent optical element traversed by the light beam constitutes a primary screen.

The light source may be of the filament lamp type, the least expensive. But we can replace it with one or more diodes electroluminescent, especially in the case where the light source is associated with the Fresnel lens 1.Use electroluminescent diodes light source has advantages: we can then afford to use "crystal", that is to say non-colored, output ice-creams, since the fire color can be obtained directly by the appropriate choice of the diode: we can obtain so-called "Californian" fires, that is to say all white. In addition, the light-emitting diodes are "cold" and heat-resistant compared to conventional filament lamps, the distance between the diodes and the screens can be reduced, and in fact very compact lights in depth.

The screen E is a concentrator screen, crystal or colored, in one transparent or translucent material. It consists of a set of patterns 3 to ensure the output of the screen, by direct transmission and / or by internal reflection, a spatial distribution of light energy in areas localized 4 almost punctual, having the appearance of pixels or points elementary. Screen E is located inside Fire A and is lit by the stream bright 2.

The elementary pattern 3 of the screen E has the shape of a funnel (Figs.4 and 5) delimited, on the side of the exit of the light, by a surface 5 substantially frustoconical axis parallel to that of the beam luminous. The inclination of the generatrices of the surface 5 with respect to the axis is chosen to ensure the total reflection of a light ray such as 2a which enters directly in the screen E and arrives on the surface 5. The ray 2a undergoes at least another internal reflection before leaving pattern 3 by zone 4.

The frustoconical surface 5 is connected, by its small base, to a pawn cylindrical coaxial 6 protruding forward of which the front end, orthogonal to the axis of the surface 5, constitutes the localized zone 4. The pattern 3 is delimited, from side of the entrance of the light, by a cavity of revolution 7 to meridian in Right angle bleachers, promoting total reflection.

The cavity 7 (see FIG. 5) comprises a cylindrical central portion 7a whose bottom 7b is orthogonal to the axis of the pattern and to the direction of the beam 2, to allow direct transmission as shown for the light beam 2b in Fig.1. The open end towards the rear of Part 7a is followed by a first annular surface 7c orthogonal to the axis of the pattern 3, then by a cylindrical surface 7d of larger diameter than the central portion 7a, leading to the back of the screen E.

The front end of the pin 6 is orthogonal to the axis of the pattern 3 and is advantageously provided with at least one and preferably several patterns 8, torus type, suitable for ensuring the spatial distribution of the outgoing light.

The input diameter De (FIG. 6) of a pattern 3 may be of the order of 20mm, while the outlet diameter Ds, corresponding to the diameter of the pawn cylindrical 6, is of the order of 5mm. More generally, the relationship between input diameter De and the output diameter Ds is of the order of four (per example between 3.5 and 4.5, especially between 3.8 and 4.2). Patterns 3 can be organized in honeycombs, the centers of the two-row patterns successive ones being shifted so that one obtains a configuration hexagonal centers. The pitch of the reasons, that is to say the distance between two neighboring centers, is then 17.3mm with the numerical example of dimensions of the previous pattern 3. We can adopt a pattern matrix organization with centers aligned on orthogonal rows and columns between they; the pattern pitch is then 14.1 mm with the same numerical example of dimensions.

Of course, it is possible to have different parameters, in depending on style requirements or point constraints.

The screen E may be circular in shape as illustrated in FIG. rectangular shape or other, depending on the style sought. The screen E is molded in one piece, the material used being PMMA (polymethyl methacrylate) or PC (polycarbonate) according to thermal constraints.

The color of the primary screen, constituted by the lens 1, can be crystal (colorless), red or green to achieve colorimetry by synthesis subtractive with a conjugate color exit glass.

According to the representation of Fig.1 and Fig.7 the reasons 3 are organized in a plane system orthogonal to the axis of the light beam. Alternatively, can slide each element 3 parallel to the direction of the beam luminous to obtain apparent exits distributed in the space, by example according to a surface parallel to an exit ice G inclined by vertical ratio. Fig.10 shows the back of a screen E whose elements 3 have undergone such a shift leading to a three-dimensional version.

A B-style screen consisting of an opaque plate comprising distributed holes to receive the pins 6 is advantageously provided for hide the concentrator screen E. Only the front ends of the pawns 6 (Fig.8), through which the light can go out, are visible. These ends front of the pins 6 can protrude on the screen B to improve the vision lateral. Alternatively, the front ends are flush with the surface of the screen B.

The operation of the traffic light is illustrated by Fig.6 which shows a section of a pattern 3 and illustrates the management of light and the light ray behavior inside the screen E.

The set of collimated rays of the incident light beam 2 is concentrated towards the apparent exit zone 4 constituted by the end before the cylindrical pin 6. The main outgoing beam 9 is in the extension of the pin 6. A cone beam 10 whose angle at the apex depends on the inclination of the generators of the frustoconical surface 5 is in additionally obtained. Various light rays of lesser intensity are scattered.

In the example of Fig.6 the angle of inclination of the generators of the surface 5 on the axis of the pattern 3 is about 30 °.

All light rays falling on the entrance face of pattern 3 are well transmitted to the outside without loss of efficiency. The extremities 4 of the pawns 6 have the appearance of a led and constitute points luminous separated, discreet.

The set of patterns 3 makes it possible to transfer most of the energy light entering the screen E and ensures its spatial distribution output. All It is as if the screen E was a flat, neutral screen with two parallel faces.

A beam such as 2a enters the pattern 3 through the face 7c (Fig.5) orthogonal to the radius and undergoes internal reflection on the surface frustoconical 5. The reflected ray is returned to the cylindrical surface of the pion 6 where he undergoes a new internal reflection to reach the front of the pawn 6 from which he comes out undergoing a refraction.

The radius 2b which enters the pattern 3 by the bottom 7b (FIG. without deviation the pattern 3 and the pawn 6.

Fig.2 shows an alternative embodiment according to which the system optical S includes a parabolic reflector R whose focus is confused with the center of the filament of the lamp L. The concentrator screen E is similar to that of Fig.1, with style B screen.

Fig.3 shows in vertical axial section a traffic light, similar to that of Fig. 1, intended to constitute a direction indicator or flashing amber, with a crystal E screen.

The embodiment of FIG. 3 aims at ensuring an improvement of the appearance traffic light at the rear of the vehicle when it is off. It is recalled that the rear traffic lights, when turned on, have different colors depending on their function. The backup light is usually white, the direction indicator is usually orange or amber, while the stop and tail lights are red. When the fires are extinguished, it may result in different aspects in the block rear view of the vehicle. Some builders want the appearance of the rear signal block (when off) is more uniform and a homogeneous color, usually red.

FIG. 3, using the principle of subtractive synthesis of colors, offers a flashing amber whose red appearance, when off, is significantly improved. A similar provision could be provided for the reverse light.

The red Ga exit ice has, in areas such as 11 traversed by a beam from a pin 6, an area 12, forming a pellet, of pink hue allowing to obtain at the exit a beam of amber color by subtraction of color. A white backup light can be obtained with a screen primary 1, S green and pink 12 areas. A flashing function / indicator direction can be obtained with an amber L lamp or a primary screen 1, S amber and pink areas 12. The size of the pink tablets on the ice cream is chosen in particular according to the distance separating 6 pawn pellets: the closer the distance is, the more the pellets may be small, the objective being that the pellets recover the entire light (or most of the light) coming out from the corresponding 6 pawns coaxial.

The surfaces of the zones 12 are reduced, which makes it possible to minimize consequently the pink surface of the exit ice. The dimensions pink zones 12 are adapted to the distance between the pin 6 and the ice Ga. The more the pieces 6 are close to the ice Ga, the more the zones 12 are small. The Illuminated surface area is very discreet.

The invention makes it possible to obtain, with a conventional lamp system, a signaling light having an appearance similar to that obtained with LEDs much more expensive. However, as mentioned above, the invention also allows to select one or more light-emitting diodes as a light source, in order to obtain fires of different example more compact or "crystal" version.

The light output of optical systems using the concept of reflection is excellent.

The red appearance of a traffic light, at the level of the functions flashing and reversing, can be improved by increasing the trompe-l'oeil effect for the final observer.

Claims (17)

Signaling lamp for vehicles comprising at least one compartment equipped with at least one light source (L), with an optical system (S) for forming a beam, a screen (E) in front of the lamp and an exit window (G) ), characterized in that the screen (E) is in a transparent or translucent material, and comprises a set of patterns (3) for ensuring output of said screen (E), by direct transmission and / or by internal reflection , a spatial distribution of the light energy in localized areas (4), in particular almost punctual, transferring the bulk of the light energy entering the screen. Signaling light according to claim 1, characterized in that the set of patterns (3) comprises a repetition according to a determined geometrical arrangement of an elementary pattern (3). Signaling light according to claim 1 or 2, characterized in that the elementary pattern (3) has the shape of a funnel delimited, on the output side, by a substantially frustoconical surface (5) of revolution of axis parallel to that of the light beam, which is connected by its small base to a cylindrical pin (6) coaxial projecting forward, this funnel being delimited on the side of the inlet by a revolution cavity (7) stepped meridian. Signaling light according to claim 3, characterized in that the steps of the cavity (7) are substantially at right angles, favoring total reflection. Signaling light according to claim 3 or 4, characterized in that the revolution cavity (7) comprises a central cylindrical portion (7a) whose bottom (7b) is orthogonal to the direction of the beam to allow direct transmission, the open end towards the rear of this cavity being followed by a first annular surface (7c) orthogonal to the direction of the beam and then by a cylindrical surface (7d) of greater diameter than the central part, opening on the rear face of the screen. Signaling light according to one of claims 3 to 5, characterized in that it comprises a style screen (B) pierced with holes adapted to receive the ends of the pins (6), this style screen masking the patterns which are find behind him. Signaling light according to claim 6, characterized in that the ends pawns (6) protrude on the style screen. Signaling light according to one of claims 3 to 7, characterized in that the front end of a pin is provided with at least one pattern (8), of the torus type, suitable for ensuring the spatial distribution of the light outgoing. Signaling light according to one of the preceding claims, characterized in that it comprises a collimator system comprising a Fresnel lens (1), or a parabolic reflector (R). Signaling light according to one of the preceding claims, characterized in that it comprises a primary screen (1, S) of crystal or red color. Signaling light according to one of Claims 1 to 9, characterized in that it comprises a green primary screen (1, S) for producing subtractive synthetic colorimetry, with an output mirror (G, Ga) of conjugated color. Signaling light according to one of the preceding claims, characterized in that the screen (E) is in three dimensions with sliding of each elementary pattern (3) parallel to the direction of the light beam to obtain apparent outputs distributed in the space. Signaling light according to one of the preceding claims, characterized in that the ratio of the input diameter (De) of a pattern (3) to the output diameter (Ds) is of the order of three to five, preferably of the order of four. Signaling light according to claim 13, characterized in that the input diameter (De) of a pattern (3) is of the order of 15 to 25 mm, in particular of the order of 20 mm, while the diameter output (Ds) is of the order of 3 to 10 mm, in particular of the order of 5 mm. Signaling light according to one of the preceding claims, characterized in that the red exit window has pink areas (12) of reduced area corresponding to the useful surface illuminated by the output of a pattern (3) of the screen , to improve the red appearance of a signaling function, such as reversing light or direction indicator. Signaling light according to one of the preceding claims, characterized in that the light source (L) is an incandescent lamp or one or more electroluminescent diodes. Motor vehicle characterized in that it is equipped with at least one signaling light according to at least one of the preceding claims.

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