WO2003031727A1

WO2003031727A1 - Illumination system

Info

Publication number: WO2003031727A1
Application number: PCT/NL2001/000652
Authority: WO
Inventors: Ireneus Johannes Theodorus Maria Pas
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-10-08
Filing date: 2001-10-08
Publication date: 2003-04-17
Anticipated expiration: 2004-04-08
Also published as: TW538180B

Abstract

The present invention relates to an illumination system (1) for insertion into a recess (102, 103) in a surface (101), wherein said system comprises a light emitting part (2) having a light emitting side (4), and a light generating part (3), said light emitting part comprising a plastic body (5) encapsulating one or more optical fibres (6), said light generating part (3) comprising a housing including at least one light source (8), wherein said light emitting part (2) and said light generating part (3) are fixedly coupled into an elongate integrated body, and said system (1) comprises at said light emitting side (4) an arm (9) which extends parallel with said light emitting side (4).

Description

ILLUMINATION SYSTEM

The present invention relates to an illumination system for insertion into a recess in a surface, wherein said system comprises a light emitting part having a light emitting side, and a light generating part, said light emitting part comprising a plastic body encapsulating one or more optical fibres, said light generating part comprising a housing including at least one light source, wherein said light emitting part is coupled to said light generating part.

Such an illumination system is known from WO 00/20691. In this document, a description is given of a road-marking complex, which is accomodated in a recess in a road surface. The road- marking complex comprises a box-like base module in which end portions of optical fibers end. These fibers may be illuminated by a distant light source, or by a LED-module with a completely closed housing, forming part of the base module. The base module may be provided with screw openings for fastening it into the recess.

A drawback of this road-marking complex is that it is difficult and time-consuming to remove said complex from said recess. However, it is desirable that this can be carried out quickly, because the traffic should be hindered as little as possible, and for as short a time as possible.

At the same time, it is impossible to easily recover the light generator part when removing the complex, since the light generator forms a part of the unit. Or, in the case of a distant light generator, a separate recess should be made for the light generator and light guides between light generator and optical fibers should be made and coupled therewith. This is bothersome for its quick removal. Furthermore, the box-like shape of the complex has the disadvantage that it is to be placed into a relatively deep recess with vertical walls . In a practical embodiment of the complex the housing for the light generator has a height of 8 cm. This adds up to the thickness of the base module. Thus the total height of the complex is more than the thickness of e.g. ordinary ZOAB (Zeer Open Asfait Beton = Very Open Asphalt Concrete) , which is about 5 to 7 cm. This means that the ZOAB- compartments to either side of the complex can no longer communicate with eachother, which has a negative effect on drainage properties. Moreover, the surface may warp. Together with the relatively high vertical walls of the recess, this may give rise to steplike height variations on both sides of the complex. This is very dangerous, especially for bicycles and motorcycles .

It is an object of the present invention to provide an illumination system of the type described in the opening paragraph, which relieves the above-mentioned drawbacks.

Thereto, the illumination system according to the invention is characterized in that the light emitting part and the light generating part are fixedly coupled into an integrated body, and that the system comprises at the light emitting side an arm which extends parallel with the light emitting side.

In use, an illumination system according to the invention has been accommodated in a recess in a surface. It can be quickly and easily removed therefrom. The integrated body may be taken out of the recess and separated into a light generating part and light emitting part. Alternatively only the light emitting part may be removed. All this will be described later on.

In this application, a recess is to be understood as a space that has been left out in a body, which space communicates with the environment. This left out space may be for example a groove, a slot or a hole. The body in which said space has been left out may be anything with an at least locally flat or smoothly curved surface, from a wall, the ground, a road, a roof, et cetera. The recess may be pressed, milled, drilled, cut and so on. The recess need not have a uniform depth. For example, the recess may have a central area with a depth which is greater than that of bordering areas. This may be useful when accomodating a light generating part beneath (with respect to the surface) a light emitting part. Here, the light generating part may be fitted into a small but deeper hole, whereas the part of the recess for the light emitting part may be relatively flat. It is even contemplated that only the light generating part is accomodated into the recess, whereas the light emitting part is spread out over the surrounding surface.

The length of the system is its largest dimension as measured in a tangent plane to its light emitting side. Preferably, it has a length which is substantially greater than the width thereof. This embodiment is very suitable for long stretches of lighting. Furthermore, it will be easily and effectively fastened to the surface into which it is fitted.

When the illumination system is in use, the arm which extends from the integrated body covers part of the surface into which a recess has been provided for accommodating the system. This means that any step in height between both sides of the illumination system is smoothly bridged by the arm. Furthermore, the use of such an arm makes it possible to provide a very shallow illumination system, which leaves at least part of the upper surface layer, e.g. of the ZOAB, intact. This means that problems like a severed fluid communication between both sides of the surface layer or a step-like height difference therebetween are much less likely to occur.

It should be noted that in this application, the words "fixedly coupled into an integrated body" are intended to mean that the light emitting part and the light generating part are coupled such that they are substantially immovable with respect to each other. This ensures that the light emitting part and the light generating part may be removed from the recess, and handled in general both at the same time. If the light generating part and the light emitting part were to be coupled e.g. by means of a long and flexible light guide, this would not be possible.

Furthermore, the coupling is meant to be separable. The integrated body comprises a light emitting part and a light generating part which may be separated if desired. E.g. these parts are not enclosed by a common encapsulation, neither do they form one inseparable unit.

"Arm" is intended to be a narrower portion projecting from the main body. Expediently, the width of the illumination system including the arm is greater than the width of the illumination system less said arm, wherein the width is measured in a cross- section through said system through said arm and parallel to the light emitting side of the illumination system.

The words "light emitting side" refer to that side of the illumination system from which, when in use, light is emitted.

In general, the light emitting side may be equalled to a tangent plane to the illumination system which plane is substantially parallel to the surface into which it is inserted.

In a preferred embodiment of the illumination system according to the invention, the arm extends over substantially the complete length of the system.

In this way, a smooth transition of one side of the illumination system to the other side is ensured over the complete length thereof. Furthermore a relatively large contact surface area is thus provided by which said arm, and hence the illumination system may be fastened to the surface. However, it is possible that the arm extends only over part of the length of the illumination system. This may be advantageous because of savings in the use of material for the arm. Furthermore, if more than one arm along the length of the illumination system is used, an additional effect, comparable to the use of so-called cat's-eyes, may be obtained. I.e., by using several arms in a row, slight bumps may be experienced when driving across the illumination system, in the case said system is accommodated in a road surface, and partly protruding therefrom. Advantageously, the system comprises at least one arm on either side of a longitudinal axis thereof. In this way, an even smoother transition between both sides of the illumination system is possible. Furthermore, a more reliable fixation to the surface is ensured. In some cases, however, only one arm is sufficient. For example, in the case of a line along a margin of the surface, e.g. a boundary line of a road, it may be advantageous in terms of cost effectiveness to use only one arm, on the side facing the center of the surface. In a preferred embodiment of the illumination system according to the present invention, at least one arm comprises, opposite the light emitting side, a corrugated surface. Because of the corrugation, not only is the friction between the arm and the surface covered thereby increased, but moreover the inclusion of air can be prevented when the arm is e.g. bonded to the surface. If some other fastening means are used, it is also possible for said surface to be smooth, or to have a different surface roughness, for example dots or bumps.

Preferably, at least one arm forms a unit with the plastic body. This ensures a lower number of parts, thereby lowering production costs by increased simplicity of the design. It may however be possible for the arm and the plastic body to be different parts. This may be advantageous if the material of the plastic body, which encapsulates the one or more optical fibers, is much more expensive or e.g. slippery than is desirable. In that case a different material may be used for the arm(s). Even then, however, the plastic body and the arm(s) may be fastened to each other to form a unit for ease of handling.

Advantageously, the plastic body is substantially made of a plastic material chosen from polyurethane or bioresin systems . These materials are very durable and tough. Especially in outdoor uses, notably road surfaces, they are very resistant to solar radiation and to the repeated impact by traffic. In case the light emitted by the optical fiber(s) travels partly through the material of the plastic body, e.g. when the end portion of the optical fiber is covered by the plastic material of the plastic body, it is important that said plastic material does not opacify. Said polyurethane and bioresin systems ensure this permanent transparency.

Said polyurethane systems may for example be Megidur as produced by Bayer AG. Bioresin systems are meant to comprise non-biodegradable polymers based on biological raw materials, i.e. rape seed, and so on, specifically excluding petrochemical products.

It is however not strictly necessary to use these materials for the plastic body. For example, when the illumination system is to be used on a crash barrier or vertical surface, less tough materials may be used. If the end portion of the optical fiber is not encapsulated by the plastic material of the plastic body, the material need not be transparent. In this case, the plastic material is expediently filled with substances that increase the durability and radiation resistance of plastic material, e.g. carbon black, titanium dioxide, etc. Also, other filling materials may be used to improve other properties of the plastic material. This will be elucidated further on. If the illumination system is to be used in e.g. a tunnel or other "indoor" environment, radiation resistance is not important, and any, preferably cheap, plastic material may be used.

In a preferred embodiment of the illumination system according to the present invention, the one or more optical fibers comprise plastic optical fibers. Plastic optical fibers, for example made of PMMA or polyamide, combine a low price with good optical properties, viz. low absorption and a high numerical aperture. This means they may carry a high optical power density. Nevertheless, if desired other materials may be used for the optical fiber. For example glass fibers may be used in a particularly hostile environment, which glass fibers have been enclosed in a high-temperature plastic, for use with temperatures above 100°C or even higher. Otherwise, for the lowest light absorption or for transport of ultraviolet radiation, quartz glass fibers may be used. The optical fibers may be mounted in the plastic body in very many ways. For example all fibers may emit light in mutually parallel bundles. Or part of the fibers may emit light in one direction, whereas another part of the fibers emit light in another direction. Expediently, these directions may be substantially opposed. This is very advantageous when the illumination system is used as a traffic marker, for example a lane marker. This way, traffic coming from both ways may observe the light emitted by the illumination system. Preferably, when in use, light rays leaving the one or more optical fibers form an angle of between 0.5° and 12° with the light emitting side. When light is thus emitted by the optical fibers, optimum visibility is ensured at many different distances from the illumination system. For example, when the illumination system is used as a traffic lane marker, the light will be visible from about 115 meters down to about 5 meters, when the eye of the observer is at a height of 1 meter, which is roughly the height of the eye when driving a car. Different emission angles are however not excluded. Different angles up to 90° may be advantageous when the illumination system is e.g. to indicate a sharp turn, or the end of a road.

The end portions of the optical fibers may slightly protrude from the plastic body. Alternatively, the emission faces of the end portions of the optical fibers may lie flush with a surface of the plastic body. This way they are better protected against external influences, notably dust, or mechanical influences. Preferably, however, the end portions of the optical fibers are completely surrounded by the plastic material of the plastic body. This way the end portions are even better protected. In a preferred embodiment of the illumination system according to the present invention, one or more optical elements are present near an exit end of the one or more optical fibers. Such optical element may for example be a lens, or a prism. Preferably, the optical axis of the lens is parallel with the optical axis of the corresponding end portion of the optical fiber. In an advantageous embodiment, the optical axis of the lens and the optical axis of the end portion of the optical fiber coincide. However, it is possible for said optical axes to not coincide, thereby being able to direct the beam emitting from the end portion of the optical fiber away from the optical axis thereof.

It is possible and preferable to fabricate the optical element from substantially the same material as the plastic material of the plastic body. For example, such an optical element may be made beforehand, after which it is encapsulated by the plastic material of the plastic body. This may be advantageous because most properties of the material of the optical element and the material of the plastic body will be equal, e.g. expansion properties. Use of such substantially compatible materials may still be effective when the plastic material of the plastic body is e.g. filled with a filler material and hence opaque, whereas the material for the optical element is transparent. The optical element may be made from a material different from the plastic material of the plastic body. The material for the optical element may be chosen because of its reflection properties, its absorption property etc.

In another preferred embodiment, the end portion of the optical fiber is first encapsulated by transparent material for the optical element, in such a way that a face of the optical element which ultimately emits the light functions as the optical element. For example, this face may be curved so as to form a lens. This will be elucidated in the description of the drawings .

Preferably, the plastic body comprises skid resistance increasing means on at least part of the light emitting side.

This has certain advantages when the illumination system is used as e.g. a traffic marker, because then vehicles may drive across it without a risk of skidding because of decreased resistance between tire and illumination system. Vehicles should then not experience a skid resistance which is different from the skid resistance of the surrounding surface. This is especially true if the skid resistance of part of the illumination system with which the traffic comes into contact has a very low skid resistance. In most cases, traffic will come into contact with a face of the plastic body of the illumination system. When no special measures are taken, in most cases the plastic material of said plastic body will, especially when wet, have relatively low skid resistance. This is especially dangerous for cyclists or motorcyclists .

Preferably, the skid resistance increasing means comprise mineral grains having a hardness of more than 7 on Mohs' scale, and being at least partly enclosed by the plastic material of the plastic body. Thus embodying the skid resistance increasing means is reliable and durable. Although the limit of 7 units of Mohs'- scale is not very strict, it should not be much lower than this, because then frictional forces of traffic driving across the illumination system, or even grains of sand being blown across it, will polish the mineral grains. This would cause the skid resistance of the illumination system to decrease unfavourably. If however the hardness of the mineral grains is more than 7 on Mohs" scale, the danger of the skid resistance decreasing by the above mentioned mechanisms is much lower, a higher number of units corresponding with a higher abrasion resistance. Preferred materials for the mineral grain are ceramic materials, e.g. SiC, Al₂0₃ etc., which may have a hardness of up to 9.5 on Mohs¹ scale.

In a favourable embodiment of the illumination system according to the invention, the at least one light generating part and the at least one light emitting part are coupled by snap connection means. It should be noted that connection may refer to mechanical connection and/or optical connection between one or more light generating parts and light emitting parts.

Snap connection means are very favourable for easy connection of light generating parts and light emitting parts. For example, said snap connection means may be in the form of a plug on one of two parts to be connected, and an insertion hole on the other part. Said plug may be formed by end portions of the optical fibers, opposite the light emitting ends, while said insertion hole may be formed in the light generating part, and may be opposite a source of light, e.g. one or more LED's etc. This way, both a mechanical and an optical connection may quickly and separably be made. Alternatively, said plug may be formed in the light generating part, while said insertion opening may be formed in said light emitting part. Other connection means are not excluded, however. E.g. bonding may be used, or a screwed connection for optimum stability. Preferably, the snap connection means comprise a guiding surface. A guiding surface is meant to be a surface in the center of which one of the connection means, i.e. a plug, an insertion opening or any other connecting means known in the state of the art, is present. When connecting two parts, this has the advantage that corresponding connection means do not have to be aligned before carrying out the connecting action, but may be displaced with respect to eachother. The guiding surface will ensure that both parts will become aligned during the connecting action. This greatly increases the speed with which said connecting action may be carried out, which is very important in for example road maintenance. In cases where a light generating part is already present in the surface, a light emitting part may thus be very easily and very quickly applied and connected therewith by simply bringing the two together and pushing. The correct connection will be established automatically.

The light generating part comprises one or more sources of light. A broad range of light sources may be used, each with specific advantages. Preferably, the light sources used in the illumination system according to the invention have small dimensions but still a relatively high light intensity, since the light should be carried by optical fibers. Expediently, one or more Light Emitting Diodes (LED's) are used as a light source. Nevertheless, in special cases other light sources may be used, such as small halogen lamps or solid-state lasers. LED's have many advantages, among others they are very small and have an extremely long useful life. This life may be many thousands of hours, during which time the light emission hardly changes. Furthermore they come in various colours, such as red, yellow, green and blue. By combining colours, every possible colour may be produced.

The long life of e.g. LED's is a reason for the illumination system according to the invention to be reusable. It is very likely that the illumination system is still functioning well when the surface (e.g. a road surface) needs to renewed, the illumination system needs to be removed, relocated or otherwise. As has been mentioned before, it is preferred to then first remove the illumination system from the recess as quickly as possible, thereby giving up part of the system, instead of laboriously and slowly removing the system as a whole.

The illumination system may comprise control means for controlling the one or more light sources. Preferably said control means are comprised in the light generating part, but it is possible to control said light sources via external means, e.g. a power line. This, and effects that can be achieved with suitable control means will be elucidated in the description of the figures .

The light generating part may comprise a source of energy for the light source. For example, a electrical power line may be present in the light generating part, and may be connected to the mains. Alternatively, a seperate source may be present, for example one or more solar cells and/or batteries, which may be rechargeable. Otherwise, the energy source may be outside the light generating part, there being only electrical connection means present in the light generating part.

In a preferred embodiment of the illumination system of the invention, the light generating part comprises an electrical supply cable having an insulating coat, the housing comprising sharp connection means that establish electrical contact by piercing through said insulating coat. This means that the electrical supply cable and the light generating part are two separable parts which in use are electrically connected. This is however not strictly necessary, as the electrical supply cable may be comprised in the light generating part.

The supply cable forming a separable part of the illumination system offers certain advantages. Since it is very easy to produce very long electrical supply cables, e.g. many kilometres long, it is possible to use only one cable for a long stretch of road surface, crash barrier, etc. This long electrical supply cable may be laid in a recess in said surface. It is only then that one or more light generating parts are pressed onto the electrical supply cable. Thereby the sharp connection means of the light generating part pierce through the insulation of the supply cable and establish electrical contact. Of course it is possible that beforehand the light emitting part(s) and the light generating parts have been coupled.

The invention further relates to the use of an illumination system according to the invention by accomodating the system in a recess in a road surface, a tunnel wall or a crash barrier. In these uses, the illumination system according to the invention is particularly advantageous, since they almost always require very long illumination lengths, low maintenance, and, whenever an illumination system needs to be replaced or needs maintenance, said work needs to be carried out as quickly as possible. However, the illumination system can be used in other applications, especially where long illumination systems are useful. A possibility might be guiding lighting or emergency lighting in buildings, where one or more colours show the applicable routes. Another possible use may be in large spaces such as exhibition centres. If the present illumination system is integrated into the floor, wall or ceiling of the centre, then it is possible for visitors to be guided towards a certain stand of an exhibitor by lighting those parts of the system, if desired with a particular colour. These and other possible uses will be described in more detail in the description of the figures . The invention further relates to a method of fabricating a plastic body for use in an illumination system with skid resistance increasing means according to the present invention, comprising the steps of: - providing a mould for the plastic body having an internal shape substantially corresponding with the desired shape of the plastic body, the mould comprising projections at those locations where the skid resistance increasing means are to be present in the plastic body; - providing one or more optical fibers in the mould;

- filling the mould with liquid plastic material;

- partially hardening the liquid plastic material, until it is dimensionally stable;

- taking the partially hardened plastic body out of the mould; - filling recesses corresponding with the projections with mineral grains having a hardness of more than 7 on Mohs' scale, the grains being at least partially enclosed by said liquid plastic material; and

- totally hardening said plastic body. Here, the words "dimensionally stable" have their usual meaning of the material not changing shape (e.g. bending) under the influence of its own weight.

This method offers an elegant and efficient method of enclosing mineral grains in the plastic in a very controllable fashion. By enveloping the grains with the same plastic or a compatible plastic, and adding them to the partially hardened plastic body, the continued hardening, e.g. polymerization, ensures an optimum bond between plastic body and grains.

The grains are only present where they are needed, i.e. between the locations of light emission. Furthermore, the at least partially enrobeing of the mineral grains offers very good fixation of the grains, while still allowing an efficient increase of the skid resistance of the plastic body. Even if a mineral grain is completely surrounded by the plastic material, this will be a very thin layer, which will sooner or later be worn off by traffic driving or riding across it, or other mechanical forces. After the top layer being worn off, the mineral grain with its very much higher resistance against wear, and of course the higher skid resistance, is exposed. To prevent every risk it is possible to pre-wear the surface, whereby any possible toplayer surrounding mineral grains is removed.

Before further elucidating on a method of recovering the illumination system, it is to be pointed out, that when in use, the illumination system is attached to the recess and/or the surrounding surface. Expediently, there can also be a recess in the surface having a depth which is substantially equal to the thickness of the arm. The arm can then be fixed substantially flush in said recess. This may be carried out in many different ways, for example by clamping, with bolts etc. Expediently, however, at least part of the illumination system is bonded to the recess and/or the surrounding surface. Bonding may be carried out by applying a bonding agent, advantageously a "super glue" type, which has a very high tensile strength but a relatively low peel strength. Any other suitable bonding agent may be used as well. With a peelable bonding agent the illumination system may be removed with ease and without damage. Still in normal use, the system is well bonded to the recess and/or surface.

Of course, this is only possible when the parts of the illumination system are flexible, which is the case for many embodiments .

The bonding agent may be applied on all of the surface area of the arms. However, whenever there are notches or recesses in the plastic body, e.g. where light is emitted, there is the risk of water being prevented to drain from recesses, because it is blocked by water impervious bonding agent. Hence, at these locations preferably no bonding agent is applied.

The bonding agent may be applied at the time and place of the introduction of the illumination system into the recess. However, it is preferred that it is applied beforehand, and preferably covered with a protection film. Preferably, the illumination system is attached to the surrounding surface with at least one arm, the light generating part being free. This offers the possibility of more or less suspending the light generating part, ensuring very good shock and vibration resistance. Furthermore, it allows the illumination system to be removed even more easily.

It is possible to attach both the one or more arms and the light generating part to the recess. For example, arms and light generating part may be bonded by different bonding agents. The arms may be bonded with a stronger glue than the light generating part, because the arms are subjected to much higher mechanical forces. By "slightly" bonding the light generating part as well, this part is protected against unwanted movements etc., while still the possibility remains to easily remove said part from the recess.

The invention also relates to a method of recovering an illumination system according to the invention, and having been accomodated in a recess in a surface, wherein at least one of the arms of the plastic body has been bonded to the surface, comprising the steps of

- severing every arm that has been bonded to the surface by suitable severing means;

- lifting from the recess the integrated body, comprising the light generating part and the plastic body less every severed arm; and

- separating the light generating part from the plastic body. This method is very useful when the work has to be carried out as quickly as possible, for example on a motorway, or in a tunnel. By carrying out the method according to the invention, not only can this work be carried out very quickly, but still there is the possibility of recovering the light generating part of the illumination system. In most cases, the light generating part will be more expensive than the light emitting part, since the latter comprises substantially a plastic body and optical fibers. Both may be considered inexpensive parts of the system, except where the fibers used are quartz fibers. In this case it may be better to remove the system as a whole, albeit more laboriously.

The means for severing the arms are preferably a grinding wheel or a rotating saw. With these means it is very easy to make a cut through any length of material, which is expedient when removing a long length of the illumination system, e.g. a road marker. It can be done on a continuous basis. When the arms have been severed, the rest of the illumination system, viz. the light generating part and the central part of the light emitting part, may be taken out of the recess. The latter part may be separated from the light generating part on the spot or on a distant location, e.g. a factory, where it may be reused. The remains of the light emitting part may be disposed of, since this is a relatively cheap part. The arms of the light emitting part, which are still attached to the surface, may be removed by any means available, e.g. milling, scraping, slicing, burning and so on. The arms may be disposed of as well.

The invention will now be described in more detail with reference to the attached drawing, in which:

- Fig. 1 shows a first embodiment of an illumination system according to the invention;

- Fig. 2 shows a second embodiment of an illumination system according to the invention; - Fig. 3a shows a perspective view of the second embodiment according to Fig. 2;

- Fig. 3b shows a top view of a third embodiment of an illumination system according to the invention;

- Fig. 4 shows various uses of an illumination system according to the invention;

- Fig. 5a-d show various designs for end portions of optical fibers in a light emitting part of an illumination system according to the invention;

- Fig. 6 shows a fourth embodiment of an illuminations system according to the invention, with electrical and mechanical connection means; - Fig. 7 shows a fifth embodiment of an illumination system according to the invention, with different mechanical and electrical connection means;

- Fig. 8a, b show two designs for skid resistance means for an illumination system according to the invention;

- Fig. 9 shows a detail of the skid resistance means of Fig. 8a,b;

- Fig. 10a,b show two steps in a method of fabricating a plastic body for an illumination system according to the invention; and - Fig. 11 a,b show two steps in a method of recovering an illumination system according to the invention; and

- Fig. 12, a, b show two cross-sectional views through another preferred embodiment of the illumination system.

Fig. 1 shows a first embodiment of an illumination system according to the invention, generally denoted with reference numeral 1. The illumination system 1 comprises a light emitting part 2 and a light generating part 3.

The light emitting part 2 has a light emitting side 4, roughly parallel to a surface 101. The light emitting part comprises a plastic body 5 which encapsulates optical fibers 6. Extending from the plastic body 5 is an arm 9.

The light generating part 3 comprises a housing 7 in which a light source 8 is contained. The housing 8 and part of the plastic body 2 are accomodated in a recess 100 in the surface 101.

The optical fibers 6 are e.g. PMMA-fibers ending near or flush with the light emitting side 4. Here four fibers are shown but any number may suffice, depending on the purpose of the illumination system. The plastic body 5 surrounding the optical fibers 6 may be made from polyurethane, such as Megidur from Bayer. Otherwise, it may be e.g. a bioresin system. Both types show excellent weathering and ageing resistance. They may be reinforced with various means, such as non-woven polyester mats. The material for the plastic body 5 need not be transparent or even translucent, when the light emitted by the optical fibers leaves them at the light emitting side. Be it because only part of the plastic body, viz. between the end face of the fibers and the light emitting side, is transparent/translucent, or that the fiber ends are flush with the light emitting surface. When the illumination system according to the invention is used in an asphalt road surface or other dark coloured surface, it is desirable if the plastic material of the plastic body 5 has a black or at least dark appearance, e.g. because the plastic material is coloured with carbon black or some other dark colourant. When the illumination system is turned off, the plastic body can not or hardly be discerned from the surrounding surface, which prevents road users from being distracted.

The arm 9 extends from the plastic body 5, and at least partially across the surface 101. Thus any step in the surface 101 because of height differences between both sides of the illumination system is smoothened. Although the edge of the arm and the opposite edge of the plastic body in the figure are sharp, they may be rounded, e.g. when traffic must drive across it. The light generating part 3 comprises a housing 7, which conveniently is made of plastic, but may in principle be made of any desired material. The housing 7 contains a source of light 8. Depending on the application of the illumination system, a wide range of possible light sources may be used, e.g. halogen incandescence lamps, gas discharge lamps, especially short arc discharge lamps. Preferably one or more LEDs are used. This will be further elucidated later on.

The asymmetric embodiment according to Fig. 1 may be used e.g. as a marginal line or a stop line in a road surface. Fig. 2 shows a second embodiment of the illumination system. It is now symmetrical around a longitudinal axis 10. Two arms 9 extend from the plastic body 5. Furthermore, the recess into the surface 101 now comprises a shallow part 102 into which the arms are let, and a deep part 103, in which the light generating part 3 and the plastic body 5 are accomodated. This way, it is possible to make the illumination system flush with the surface 101. Since no obstruction of e.g. traffic takes place, many advantages are obtained, such as less or no noise or mechanical stresses when traffic drives across the system. Since the arms 9 need only contain a part of the optical fibers 6, they may be made very thin, e.g. 5 to 10 mm. This indicates that it is not necessary to accomodate them in a recess in the surface 101.

The second embodiment of Fig. 2 may e.g. be used as a lane marker, a tunnel wall light, a guiding light in the floor of large halls etc. Fig. 3a shows a diagrammatic perspective view of the second embodiment of Fig. 2. Here there are shown eight locations where an end portion 11 of an optical fiber emerges at the light emitting side. Each optical fiber also ends at a light source 8. This may be a single light source for all optical fibers . Alternatively, each fiber or group of fibers may have its own light source, which may then be distributed more or less regularly along the length of the illumination system.

In this second embodiment, both arms 9 have a constant width. Recesses for such embodiments may very easily be made in a surface, e.g. by milling two coaxial grooves with a different depth.

When ZOAB is milled, it is possible that it will start to crumble, due to traffic load etc. To prevent any adverse effect thereof on the illumination system, the following may be done. First a recess is milled in the ZOAB. Next a receiving body, which is to receive the illumination system, is formed in the recess. For example, a liquid mass of curable mass, such as a bioresin system, is poured into the recess. During curing of the mass it is formed into a receiving body, mainly consisting of a slightly narrower and shallower recess, by means of a moulding tool e.g. a wheel pressed into the mass. Into this narrower recess, the illumination system is fitted.

A preformed body may be used, however. This may be a kind of trough, putter and so on, coiled up in great lengths. This trough, etc. may be fastened to the recess in the ZOAB by means of a bonding agent. An important advantage of this moulded mass or trough is that it is waterimpervious . Thus the illumination system is better protected. Furthermore, when the illumination system is or has been fitted into the recess in the moulded mass or into the trough, the remaining space may be filled with water repellent means, e.g. a gel. This further protects the system against water.

The curable mass or trough does not form a part of the illumination system proper. It will not interfere with the removing thereof from the recess into which it is fitted. It is noted that the above-mentioned problems are much less likely to occur with other materials such as asphalt. Furthermore, it is possible to treat ZOAB to prevent crumbling. E.g. it may be sprayed with a liquid curable plastic, e.g. specific bioresins. This effectively prevents the crumbling problems .

In Fig. 3b a third embodiment is shown, in which there are many arms 9, or alternatively two arms with varying width. Here opposite parts of the arms form more or less circles. In each circle four end portions 11 of optical fibers emerge and emit light, although some other number is also possible. The round shape of the arms 9 has an advantage that, by having them protrude from the surrounding surface, they form so-called cat's-eyes. Cat's-eyes cause a signal to be heard by cars driving over them. This embodiment combines optical and acoustical warning, which makes it a very safe means for guiding traffic. Needless to say, the shape of the parts of the arms need not be circular, but may also be square, triangular and so on.

Fig. 4 shows a number of applications of the illumination system according to the invention. A tunnel 12 is shown in which la-d represent four different uses of the illumination system, la is a ceiling light, to indicate the center of the tunnel and to be seen from afar by traffic in a crowded tunnel, lb indicates a guiding light for e.g. cyclists. Alternatively, it may be an emergency illumination, only to be turned on when there is a power failure. For this reason, it may be connected with batteries, instead of mains power. lc is a system indicating a kerbstone or gutter, to be avoided by traffic. Note that here one arm extends perpendicularly to the other. Of course, each of the two arms now has its own light emitting side, also perpendicularly to the other.

Id is the lane marker as shown before, and will not be discussed further here. In Fig. 5 there are shown six different ways to embody the end portions 11 of the optical fibers.

Fig. 5a shows a flat light emitting side of the plastic body 5, near which side two end portions 11 are shown. The end portion on the left ends slightly below the surface of the plastic body, whereby the end portion is protected against mechanical stresses, dirt etc. The end portion on the right however is flush with the surface of the plastic body 5.

Both end portions may emit a bundle 13 of light, of which only the right bundle is shown. In principle it is symmetric around an axis which is equal to the longitudinal axis of the end portion 11 of the optical fiber, as indicated by the dashed line. However, by specially designing the end face of the optical fiber, other shapes of the bundle 13 are possible. Such design may suitably be chosen by the person skilled in the art. Fig. 5b shows an embodiment in which end portions 11 end in a protrusion above the light emitting side of the plastic body 5. By suitably directing the end faces of the end portions 11, it is possible to obtain bundles 13 of light, that shine in opposite directions. This way it is possible that every protrusion, and hence the illumination system, is visible from two sides, e.g. both directions of the traffic in a road.

Fig. 5c shows a plastic body 5 of which the light emitting side has a more or less zig-zag shape. In this embodiment, the end portions 11 emit their bundle 13 of light from a recessed groove, thus somewhat better protected. Again it is possible to have the end portions 11 end flush with (left) or somewhat below (right) of the surface of the plastic body 5.

Fig. 5d shows an embodiment in which not only the end portions 11 end somewhat below the surface of the plastic body 5, but they are also provided with an optical element 14, 15 respectively. Optical element 14 is a positive lens in which the left end portion 11 ends. The positive lens may be designed and positioned such that the (left) bundle 13 emitted by the fiber is a substantially parallel bundle. Thereto it is possible to choose a material for the lens 14 which is different from the material of the plastic body 5, e.g. because it has a higher index of refraction, or is dimensionally more stable. But it is possible to have the same material for plastic body 5 and lens 14, by suitably shaping the lens 14. In the right of the Fig. the optical element 15 is a negative lens. This may be useful when a wider bundle of light is to be obtained with a single optical fiber.

Other optical elements which are possible are for example prisms, or beam splitters, for emission of light in two directions at the same time.

Fig. 6 shows a fourth embodiment of the illumination system according to the invention. The light emitting part 2 comprises two insertion holes 16. The light generating part 3 comprises snap means 17 with a guiding surface 18, which snap means snap into the insertion holes 16.

Optical fibers 6 in the light emitting part 2 end opposite light sources 8 in a housing 7 in the light generating part 3. Light sources 8 are provided with optical elements 19, and are electrically connected to some power source by means of (diagrammatically shown) electrical connection means 20 that end in a plug 21.

The insertion holes 16 may form a single groove around the plastic body of the light emitting part, or may be one or more separate incisions into said plastic body. The insertion holes correspond with snap means 17, which are somewhat resilient to give way for the plastic body to be partly pushed therebetween and "clicked" in a reliable and controllable position.

To decrease the required accuracy with which parts 2 and 3 need to be positioned with respect to eachother, snap means 17 are provided with a guiding surface 18. The guiding surface 18 will guide the plastic body 5 to a correct position between snap means 17, thereby simplifying and quickening the alignment procedure.

Light sources 8 may be, and preferably are, one or more LEDs. LEDs have an extremely long life, a constant light output, high efficiency etc. Moreover they are a very compact light source and may be distributed along the length of the light generating part. This way the shortest possible length of the optical fibers 6 may be ensured. The light emitted by the light sources 8 may be bundled with the help of optical elements 19.

These may be positive lenses, or any other desired shape. A main purpose of the optical elements 19 is to improve the coupling of the light emitted by the light sources 8 into the fibers 6.

Fig. 7 shows a fifth embodiment of the illumination system according to the invention. Snap connection means 16', 17' and 18' are present, as well as different electrical connection means 22 to 26. Furthermore, the light source 8 comprises control means 27.

Here, the snap means 17' and the guiding surface 18' are present on the light emitting part 2, whereas the insertion holes 16' are present in the light generating part 3. It is also possible to have cooperating guiding surfaces on both the light emitting part 2 and the light generating part 3.

It is moreover possible to use other means to bring and hold the light generating part and the light emitting part in an optically aligned position, e.g. screw means, transparent glue etc. Even in the case of snap means, the use of some transparent mass between the light generating part and the light emitting part is advantageous in that it may decrease reflection losses, and prevent dirt and dust from interfering with the connection, and diminishing the optical quality thereof. In the case that the LED is encased in a body with a lens, the refrective index n of the transparent mass should be selected carefully. It should differ from that of the material surrounding the LED, because otherwise the lens function is lost. In the case that a separate lens or other optical instrument is interposed between the LED and the light emitting part, a similar constraint is to be observed.

The electrical connection means comprise sharp connection means 22 that pierce through the insulating coating 26 of a supply cable 23. The supply cable comprises two cores 24 and an date wire 25. Here the date wire serves control purposes. It may however also be an earth wire, e.g. in cases where higher voltages are used.

The sharp connection means 22 protrude from the light generating part 3. Said part 3 may be pushed onto and partly into the cable 23 in order to establish an electrical connection between the part 3 and the cable 23. The pushing continues until the sharp connection means touch the cores 24. The earth wire 25 may also be a control wire for transmission of control signals. Control means 28 may serve the purpose of controlling and operating the light source 8, and may, if desired, in turn be controlled via the earth wire 25 of the supply cable. For example, the control means may turn various light sources on and off, when desired. This may be done to bring about a change in the lane marking, by the steady burning of a selected group of light sources. Also, by turning light sources on and off in a particular regular fashion, a moving signal may be simulated, e.g. to indicate a certain advised or maximum speed.

Alternatively, it is possible for the control means to change the colour of the emitted light, by either changing the active light source, or adjusting the light source. This may be used to give extra information through the illumination system. It may be contemplated to indicate icy roads, or danger ahead etc. With suitably designed control means very many different ways of operating the illumination system according to the invention are possible. It should be stressed here that it is the end portions of the optical fibers that actually emit the light as seen by a person. Hence it is these end portions which are indirectly to be controlled, but this is done through controlling of the light sources.

Fig. 8a en b show two designs for skid resistance increasing means. In Fig. 8a a diamond shaped pattern is shown of patches

28 in a surface (the light emitting side) of the plastic body 5. In between the patches the end portions 11 of optical fibers can be seen.

The patches constitute parts of the surface where mineral grains are embedded into the surface layer of material of the plastic body 5. The mineral grains are very hard and through their irregular shape or at least non-rounded shape cause an increase in the skid resistance between a tire of a motor vehicle and the surface of the illumination system. The skid resistance can be made substantially equal to the skid resistance of the surrounding surface of e.g. the road surface. This may be done by varying the material of the grains, e.g. taking carborundum (Mohs' hardness ±9.5) instead of quartz (Mohs' hardness 7) to increase the resistance. It is also possible to change the relative surface area that is occupied by the resistive patches 28, or even by changes in the shape of the pattern. Fig. 8b shows an extreme case of a large relative surface area for_. the patches, because there all of the hatched area has been provided with skid resistance increasing means. It is only the end portions 11 of the optical fibers that peep out of the surface. Fig. 9 shows a detail of the patches 28 in a surface of the plastic body 5. Mineral grains 29 and 29' are embedded in the material of the plastic body 5. Of these mineral grains, grains

29 partly protrude from that surface, and cause skid resistance. Grains 29' are completely surrounded by the plastic material, albeit by a very thin layer, e.g. about 10-500 μm. This means that, when the traffic wears off this thin layer of plastic material, fresh grains will emerge. These fresh, non-ground grains may at least partly compensate for any wear, i.e. rounding, removing etc., of the grains 29 that originally projected from the surface of the patches. This way a more constant skid resistance may be provided for.

Fig. 10a and b show two steps in a possible production process for a plastic body with skid resistance increasing means for an illumination system according to the invention. 30 and 31 refer to an upper, lower mould halve, respectively. The upper mould halve 30 comprises projections 32 that correspond to recesses 33 to be present in the plastic body 5.

In a production, firstly optical fibers are mounted in the lower mould halve 31. Then the mould is closed by combining the upper mould halve 30 and lower mould halve 31. Next, liquid plastic material is fed into the mould, which liquid plastic material is allowed to partially harden. When the shape of the plastic body is stable enough, but still the plastic material has not yet completely hardened, the plastic body 5 is taken out of the mould 30,31. The plastic body 5 shows recesses 33 where the skid resistance increasing means are to be present. These recesses 33 are filled flush with a mixture of liquid plastic material and mineral grains 29. By then allowing the hardening process to come to completion, the plastic material of the filled recesses has become one with the plastic material of the plastic body 5, thus ensuring the best possible embedding of the mineral grains. It is advisable to use substantially the same material for both the to be filled recesses and the plastic body. This will allow a perfect hardened network and no mechanical stresses because of differences in coefficient of expansion etc. It is however possible to use components that react with eachother, and have many mechanical properties in common. Alternatively, part of the liquid plastic material, e.g. the part that is to fill the recesses, may comprise other filler materials. Fig 11a and b show two steps of recovering an illumination system according to the invention. In Fig. 11a an illumination system according to the invention is accomodated in a recess in a surface 101. Light generating part 3 is accomodated in a deep recess 103, as is part of the light emitting part 2. The arms 9 of the light emitting part 2 are accomodated in a shallow recess 102.

36 denote cutting lines, along which the arms 9 may be cut off, through the optical fibers 6 as well.

Arms 9 are bonded in the shallow recess 102 by means of a strong bonding agent 34, whereas the light generating part 3 is bonded in the deep recess 103 by means of a weak bonding agent 35, or by none at all. Strong bonding agent 34 may be a "Superglue" type of bonding agent, whereas the weak bonding agent may be any ordinary all-purpose glue or kit.

The cutting lines 36 may be made by any convenient means, e.g. a rotating saw, a milling cutter etc. When the arms 9 have been severed from the rest of the illumination system, then this rest may be easily lifted from the deep recess, since it is only withheld by means of the weak bonding agent 35, or by none at all. The illumination systems thus collected may be loaded on a carrying vehicle to be transported to a factory, or they may be processed on the spot.

The arms 9 remaining on the surface 101 may be removed by any means, even destructive means, be it scraping, shoveling, milling etc. because these parts may be disposed of. Fig. lib shows another stage in the recovering process. Here the light emitting part 2 (the remains thereof) and the light generating part 3 are separated, by disengaging the snap means 17 from the insertion hole 16 in a direction indicated by arrow A. This may be done either by a special tool or by using inherent resilience of the material. The remains of the light emitting means thus removed are disposed as well. On the other hand, the light generating part 3, with its light source 8, may be recycled or simply reused. Since often this is the most expensive part, which also has the least wear, this will be very cost effective to do. Fig. 12a shows a cross-sectional view of an embodiment of the illumination system with an extra trough 40. This trough 40 here consists of a tube of bioresins. The space between trough 40 and recess 100, if any, may be filled with water repellents, e.g. gel. At the bottom of the recess, a supply cable 23 is shown.

Fig. 12b shows a cross-sectional view along an illumination system. Plastic body 5 is connected to three light generating parts 3a, 3b and 3c, although any number is possible. Each light generating part is connected through a connector 41a, 41b, 41c, respectively to the supply cable 23. The remaining space may be filled with a water repellent mass, e.g. a gel. It is noted that, even when the light generating parts and/or connectors are not (very) flexible, the intermediate parts 43 of the plastic body will provide flexibility to the system as a whole.

In this description various embodiments have been described as non-limiting examples. The person skilled in the art will be able to devise various modifications without- departing from the true scope of the invention, as claimed in the attached claims. Especially, wherever a singular verb or noun is used in a claim or description, the plural is not excluded, unless specifically indicated.

Claims

C L A I M S

1. Illumination system (1) for insertion into a recess (100) in a surface (101), wherein said system comprises a light emitting part (2) having a light emitting side (4), and a light generating part ( 3 ) , said light emitting part comprising a plastic body (5) encapsulating one or more optical fibres (6), said light generating part (3) comprising a housing (7) including at least one light source (8), wherein said light emitting part (2) is coupled to said light generating part (3), characterized in that said light emitting part (2) and said light generating part (3) are fixedly coupled into an integrated body, and that said system (1) comprises at said light emitting side (4) an arm (9) which extends parallel with said light emitting side (4).

2. Illumination system according to claim 1, characterized in that said arm ( 9 ) extends over substantially the complete length of said system ( 1) .

3. Illumination system according to one of the preceding claims, characterized in that said system (1) comprises at least one arm (9) on either side of a longitudinal axis (10) of said system ( 1) .

4. Illumination system according to one of the preceding claims, characterized in that at least one arm (9) comprises, opposite said light emitting side (4), a corrugated surface.

5. Illumination system according to one of the preceding claims, characterized in that at least one arm (9) forms a unit with said plastic body (5) .

6. Illumination system according to one of the preceding claims, characterized in that said plastic body (5) is substantially made of a plastic material chosen from polyurethane or bioresin systems.

7. Illumination system according to one of the preceding claims, characterized in that said one or more optical fibers (6) comprise plastic optical fibers.

8. Illumination system according to one of the preceding claims, characterized in that, when in use, light rays (13) leaving said one or more optical fibers (6) form an angle of between 0.5° and 12° with said light emitting side.

9. Illumination system according to one of the preceding claims, characterized in that one or more optical elements (14, 15) are present near an exit end of said one or more optical fibers (6 ) .

10. Illumination system according to one of the preceding claims, characterized in that said plastic body (5) comprises skid resistance increasing means (28) on at least part of said light emitting side ( 4 ) .

11. Illumination system according to claim 10, characterized in that said skid resistance increasing means (28) comprise mineral grains (29, 29') having a hardness of more than 7 on Mohs' scale, and being at least partly enclosed by the plastic material of said plastic body (5).

12. Illumination system according to one of the preceding claims, characterized in that said at least one light generating part (3) and said at least one light emitting part (2) are coupled by snap connection means (16, 17).

13. Illumination system according to claim 12, characterized in that said snap connection means (17) comprise a guiding surface

(18).

14. Illumination system according to one of the preceding claims, characterized in that said light generating part (3) comprises an electrical supply cable (23) having an insulating coat (26), said housing (7) comprising sharp connection means (22) that establish electrical contact by piercing through said insulating coat (26).

15. Use of an illumination system according to one of the preceding claims by accomodating said system ( 1 ) in a recess

(100; 102, 103) in a road surface (100), a tunnel wall (12) or a crash barrier.

16. Method of fabricating a plastic body (5) for use in an illumination system (1) according to one of claims 11-14, comprising the steps of

- providing a mould (30, 31) for said plastic body (5) having an internal shape substantially corresponding with the desired shape of said plastic body (5), said mould comprising projections (32) at those locations where said skid resistance increasing means (28) are to be present in said plastic body (5);

- providing one or more optical fibers (6) in said mould (30, 31); - filling said mould (30, 31) with liquid plastic material;

- partially hardening said liquid plastic material, until said material is dimensionally stable;

- taking said partially hardened plastic body (5) out of said mould (30, 31); - filling recesses (33) corresponding with said projections (32) with mineral grains (29, 29') having a hardness of more than 7 on Mohs' scale, said grains (29, 29') being at least partially enclosed by said liquid plastic material; and

- totally hardening said plastic body ( 5 ) .

17. Method of recovering an illumination system according to one of claims 1-14, and having been accomodated in a recess (100; 102,103) in a surface (101), wherein at least one of said arms (9) of said plastic body (5) has been bonded to said surface (101), comprising the steps of

- severing every arm ( 9 ) that has been bonded to said surface (101) by suitable severing means;

- lifting from said recess ( 100; 102,103) said integrated body, comprising said light generating part (3) and said plastic body

(5) less every said severed arm (9); and

- separating said light generating part ( 3 ) from said plastic body (5) .