PRIOR ART The present invention relates to illumination solutions for traffic routes. The invention pertains to an illumination device and a system comprised of illumination devices for illuminating a traffic route. In particular the invention pertains to an illumination device in uses where the visibility of pedestrians or corresponding road-users is weakened by the general lighting conditions. BACKGROUND OF THE INVENTION

Different solutions are known from the prior art to improve the safety, including the illumination, of pedestrian traffic routes. Illumination devices can be roughly divided in two categories: 1) overhead illumination devices illuminating a relatively large area on a traffic route used by pedestrians and 2) illumination devices functioning substantially as warning lights only. In addition, safety improvements are sought by protecting pedestrians through passive structures such as concrete or metal bollards possibly covered in part or wholly by reflective material with the purpose of, first, reflecting light from vehicles and, second, mechanically preventing vehicles from entering an area reserved for pedestrians Illumination is typically provided using a general-type illumination device placed at a height, e.g. at over 3 meters, the sole purpose of which is to illuminate the target area. Typically, the illumination covers a long stretch before the area at which the pedestrians and vehicles meet and, therefore, the attention-generating effect of the illumination remains weak. Another problem is the rather energy-inefficient use of light as the beam of light is spread across a relatively large area. Thus it is obvious that illumination devices, placed high are best suited for increasing the overall lighting.

A problem with the prior-art solutions is that the attention-generating effect of general lights illuminating a largish area remains weak while lamps functioning as warning lights, or beacons, do not illuminate the pathway. Another problem with the beacon-type solutions is the glare in the visual field of drivers of automobiles, for example, in which case the beacon cannot be said to improve the safety of the intersection. SUMMARY OF INVENTION

Thus the invention aims to provide a solution eliminating or at least mitigating the above-mentioned disadvantages of the prior art. In particular, the invention is aimed at providing a solution for how to improve the overall safety of an intersection of two different traffic routes so that the intersection can be illuminated and the road-users can be effectively warned without causing a risk of dazzlement while at the same time minimising the risk of pedestrians being run over by a vehicle.

The objectives of the invention are achieved by an illumination device and/or illumination system according to the independent claim.

An illumination device according to the invention for improving the safety of an intersection of at least two different traffic routes is characterised by that which is presented in the characterising part of claim 1 associated with the illumination device. An illumination system according to the invention for improving the safety of an intersection of at least two different traffic routes is characterised by that which is presented in the characterising part of claim 10 associated with the illumination system.

In one embodiment the illumination device comprises at least a device body which serves as a mechanical obstacle preventing vehicles advancing along a first traffic route, such as a road, from entering a second traffic route, such as a footpath or bicycle path, for example. The device body advantageously is made of concrete and/or metal, for instance, and essentially prevents cars, for instance, from entering the area protected by the device body or at least is able to sustain a low- speed collision without being damaged. The underground portion of the device body may be concrete, for instance, and the superterranean portion metal, such as steel or similar material which is mechanically strong enough. In one advantageous embodiment the lower portion of the device body comprises a concrete part and the upper portion a metal part made from steel, for instance. In addition, the illumination device comprises a first light-emitting part advantageously in the lower portion of the device body. This first light-emitting part is adapted to illuminate the second traffic route at least in the direction of the intersection of the first and second traffic routes which second traffic route is essentially meant for light traffic. Placed in the lower portion of the device body the first light-emitting part effectively illuminates the pedestrian crossing, among other things, so that a pedestrian can cross the road more safely and also becomes at least partly illuminated so that motorists can see him better. The first light-emitting part advantageously emits substantially continuous light which may be white light, for example. Placing the first light-emitting part in the lower portion is advantageous e.g. in poor weather conditions (fog, rain, snowfall) because positioning it low and directing the light downwards help minimise potential glare.

Additionally the illumination device comprises a second light-emitting part arranged in the device body essentially above the first light-emitting part. The second light-emitting part is arranged so as to warn vehicles advancing along the first traffic route about traffic on the second traffic route, essentially at the intersection, such as a pedestrian or cyclist, for instance. The second light-emitting part advantageously emits a substantially blinking light which may be yellow light, for example. It should be noted that also the light emitted by the second light- emitting part may be continuous and of some other colour than that mentioned here.

In one advantageous embodiment of the invention the illumination device also comprises at least one third light-emitting part functionally connected with the second light-emitting part. Such a third light-emitting part can be advantageously arranged in the device body essentially above the second light-emitting part so as to be visible to drivers of vehicles advancing along the first traffic route even when there is a visual obstruction, such as a parked vehicle, near the device body.

The illumination device also comprises a light source comprising e.g. at least one light-emitting diode to produce the light. The illumination device also comprises an optical element, such as a light conductor, lense, or a combination of a light conductor and lense to conduct the light produced by the light source to the first and/or second light-emitting part and, further, out of the illumination device. In one embodiment the light conductor is a three-dimensional piece which may be cast or machined, for example. The light conductor may be shaped such that the light emitted by one or more light-emitting diodes is conducted out of the device body in a predetermined angle so that e.g. most of the light is directed downwards of the horizontal plane whereby users of the traffic route will not become dazzled. Advantageously the light conductor is adapted such that the light will propagate inside the light conductor through internal reflections, in other words the optical characteristics of the light conductor are such that essentially total internal reflection will occur between the light conductor and the surrounding space. At suitable places in the illumination device the light conductor could also be shaped such that total internal reflection will not occur but at least some of the light will be emitted out of the light conductor. In one embodiment, this is how at least some of the second light-emitting parts can be implemented. In one embodiment the second light-emitting part is placed in the illumination device essentially at the eye height of drivers of vehicles advancing along the first traffic route, advantageously at 50cm to 130cm above ground, so that the attention-generating effect of the light-emitting part on the driver is very effective. Orientation of the light-emitting part can be done e.g. by means of a light conductor and/or an optical means connected therewith, such as a prism, mirror or lense, so that the beam of light emitted is essentially directed downwards of the horizontal plane. Thus it is possible to minimise potential dazzling effect on drivers of vehicles without degrading the attention-generating effect of the light.

In one embodiment of the invention the illumination device may also comprise a means for activating the operation of the illumination device, e.g. a switch based on a light-dependent resistor, so that the first and/or second and/or third and/or fourth light-emitting part can be arranged to emit light only if the level of ambient light is low enough. Alternatively, this switch can be used to adjust the brightness of the light emitted by the light-emitting parts in accordance with the lighting conditions. The above-mentioned switch may be used e.g. to control the operation of the light source, such as LEDs, supplying light to the light-emitting parts. In addition, the illumination device or system may comprise a motion detector for detecting an object approaching the illumination device along the first and/or second traffic route, whereby also the output of the motion detector can be used to control e.g. the operation of the light source, such as LEDs, supplying light to the light-emitting parts. Thus it is possible to maximise the attention-generating effect of the illumination device as the light-emitting parts of the illumination device are active only when the ambient light level is low enough and/or motion, such as an approaching pedestrian or cyclist, is detected in the vicinity of the illumination device.

In one embodiment of the invention the motion detector can be implemented by means of a passive infrared detector, infrared or microwave barrier, camera, such as a CCD, CMOS or infrared camera, Doppler radar, induction loop or some other similar means which can detect motion or an approaching object. The illumination device may also comprise a manually operated switch, such as a pushbutton, by means of which a user of the light traffic route can manually activate the operation of the first and/or second light-emitting part in the illumination device.

In one embodiment of the invention the beam of light emitted by the first light- emitting part is advantageously adapted by means of a light conductor and/or lense, for example, so as to be a narrow wedge of light essentially directed downwards of the horizontal plane in order to enhance the illumination and minimise glare. The width of the wedge of light is advantageously 5 to 45 degrees, for example, so the power density of the wedge of light on the pedestrian crossing across the intersection area is high. It should be noted that the wedge shape can also be achieved using some other optical means known to a person skilled in the art, such as a prism, lense and/or mirror, for example.

In one advantageous embodiment of the invention the system is adapted to switch on the light of at least one light-emitting part not immediately but after a certain period of time so that the intensity of light grows from essentially zero or a very small value to essentially full brightness during the period of time. This period of time is advantageously longer than one second. Such a soft switch-on reduces the dazzling effect of the light, especially at a very dark site.

The illumination device according to the invention may comprise one or more sources of light. In one embodiment the light is directed from the light source into a light conductor and thence out of the device body by an optical means such as a prism, lense and/or mirror. It should be noted that the light source may be located e.g. inside the device body or at its base from where the light is directed through optical means, such as a prism, mirror and/or lenses, into a light conductor, and, further, in the light-emitting part, out of the light conductor through some optical means known to a person skilled in the art. In one embodiment, especially the second and/or third light-emitting part may be implemented at least partly with a fiber-optic-like light conductor so that the light conductor is bent into a curve whereby it is possible to stay below its critical angle of total internal reflection and the beam of light transmitted in the light conductor can be refracted out of the light conductor. Such a solution easily produces an even warning light effect for a desired angle between 0° and 360°.

It should be noted that the source of light can be located at some other position in the device body than at the base and that in one embodiment, for example, there can be a light-emitting diode for each light-emitting part. In addition it should be noted that in one embodiment of the invention the first and/or second and/or third light-emitting part can be implemented by the light conductor and an optical means, such as a prism, in connection therewith and that the light pattern emitted by the light-emitting part can be produced by the optical means, such as a prism.

In one embodiment of the invention the shape and/or size of the illumination pattern, such as a wedge of light, can be altered during operation. In one embodiment the illumination device can be arranged e.g. to include a plurality of light-emitting diodes (LEDs) so that the light from a first LED is conducted through a light conductor and/or other optical means producing a first illumination pattern, the light from a second LED is conducted through a light conductor and/or other optical means producing a second illumination pattern different from the first one, and so on, so that the shape and/or size of the illumination pattern can be altered e.g. by switching on, switching off and/or dimming appropriate LEDs.

In one embodiment the illumination device and/or system may include a means for changing the illumination pattern, which means can be adapted to control the change of the illumination pattern e.g. in accordance with the position of an approaching vehicle based on data received from motion detectors so that the shape of the wedge of light, for instance, changes from broader to narrower as the vehicle approaches, thus further minimising glare.

The illumination device may also include light-blocking means for preventing light from advancing outwards of the device body in a direction where propagation of light is undesired such as towards buildings in the vicinity. The light-blocking means may comprise mechanical means such as shutters, movable optical means such as lenses, light conductors and/or prisms, or alternatively the propagation of light can be prevented e.g. by switching off or dimming LEDs the light from which would be directed to an unwanted area (e.g. in an embodiment like the one described above where the illumination pattern can be adjusted). Thus, for example, the illumination pattern of the second light-emitting part (attention- generating light) can be adjusted between 0° and 360°.

In one advantageous embodiment of the invention, at least one light-emitting part is arranged so as to illuminate on a given segment of the perimeter of the device body, advantageously in a sector the width of which is at least 20°. In embodiments of the invention, there may be more than one such segment so that the system can produce different light signals in different directions. For example, the system may produce light of a certain colour to drivers of vehicles in one segment and light of another colour to pedestrians in a second segment. In one advantageous embodiment of the invention the light can be conducted into the light-emitting part through an optical element. The optical element may be a light conductor, lense, reflective surface or a combination of these, for example.

The illumination device typically also comprises a power source which may be a battery, solar cell or a wind-powered generator or a combination of these, for example. In addition (or instead) the illumination device may be powered from the electricity mains.

According to an embodiment of the invention, a plurality of illumination devices can be arranged into an illumination system. The system may comprise e.g. a control means for the centralised control of the illumination devices, e.g. to switch on/off the lights according to general environmental conditions (weather, amount of ambient light, rain, slipperiness, fog, visibility, amount of traffic) and also to synchronise the blinking of lights.

In one embodiment the illumination system may also comprise a means for gathering data, such as power consumption data and diode burning times, for example, from illumination devices and for reporting such data to a party responsible for the maintenance of the illumination system so ^" that the diodes, for instance, can be replaced at the end of their life, already before they die.

In one advantageous embodiment of the invention the device body is a substantial part of a traffic sign post. Such a traffic sign may advantageously be a traffic sign inherently associated with the installation site of the system, such as a traffic sign marking a pedestrian crossing.

In another advantageous embodiment of the invention, the system includes at least one fourth light-emitting part which is arranged to illuminate a traffic sign located in the vicinity of the installation site of the system. Such. an embodiment is especially suitable for a structure in which the device body constitutes a substantial part of the post of the traffic sign. Furthermore, the at least one fourth light-emitting part is advantageously functionally connected with the first or second light-emitting part. In such an embodiment the illumination on the traffic sign further improves the safety of the installation site of the system as the illuminated traffic sign can be more easily observed by drivers of vehicles. Furthermore, in such an embodiment the fourth light-emitting part is arranged so as to illuminate in a blinking or otherwise changing manner, thus adding to the discernability of the illuminated traffic sign. In an advantageous embodiment of the invention the device body is located in a traffic light post or constitutes a part of a traffic light post. Such an embodiment is suitable e.g. for a site where there are traffic lights for vehicles and pedestrians at the pedestrian crossing. In one advantageous embodiment of the invention the system may include one or more traffic monitoring sensors or sensor systems such as an induction loop or some other sensor for monitoring the traffic. Such a sensor may be a Doppler radar, infrared camera, passive infrared detector, visible light camera, radio- frequency radar, laser radar or an ultrasound radar, for instance. Quantities monitored may advantageously be such as the amount of traffic, instantaneous and/or average speed of traffic or the amount of traffic in different times of day, for example. This is especially advantageous in an embodiment where the system includes a control centre, in which case the system control centre can also be used for controlling such a sensor or sensor system and/or for gathering data from it. In different embodiments of the invention the sensor can be adapted to monitor either of the first and second traffic routes.

In one advantageous embodiment of the invention the quantity observed by the traffic monitoring sensor is used for controlling the operation of the system. For example, in an embodiment where speeds of vehicles are monitored by means of a Doppler radar, a driver can be alerted by a signal light or some other indication if he drives at a speed which is too high.

In one advantageous embodiment of the invention the system is adapted to determine the direction of those moving at least on one of the traffic routes, e.g. the direction in which a pedestrian is moving. The direction information can be used e.g. to optimise the illumination times of the light-emitting parts. The direction can be determined e.g. using two or more passive infrared detectors on the basis of the time differences or shapes of the signals generated by the detectors.

In one advantageous embodiment of the invention the system is adapted to determine the sizes of groups formed by those, such as pedestrians, for example, moving at least on one of the traffic routes. This information can be used for monitoring the amounts of traffic, for example. Such information, at least on a rough level, can be determined on the basis of the shape and duration of the signal produced by a passive infrared detector, for instance, as a signal produced by a group of people is differently shaped than a signal produced by a single person. In one advantageous embodiment of the invention, heat dissipation from the light- generating elements in the device body is utilised in the elimination of snow and ice. This can be done by means of thermal conductors placed in the vicinity of the light-generating elements so that the thermal conductors transmit the dissipated heat into the housing of the device body in order to eliminate snow and ice.

According to an advantageous embodiment of the invention, the system additionally comprises at least one heating element. In such an embodiment the heating element is advantageously controlled by the control centre. Advantageously the system may also include a temperature sensor which produces temperature information on the basis of which the control centre can switch on the heating element to remove snow and ice from the device body.

In one advantageous embodiment of the invention the system also includes a sensor for monitoring the amount of visible light. A passive infrared detector may react to strong variations in the amount of light, such as headlights of vehicles or the sun coming out from behind a cloud. The occurrence of such errors can be minimised by placing in the vicinity of the passive infrared detector a sensor observing the amount of visible light and using the signals of both sensors in the detection of pedestrians. If, in such an arrangement, both sensors react, the reaction is probably caused by a false alarm, i.e. the passive infrared detector reacts to a strong light and not to a pedestrian, for instance.

In one advantageous embodiment of the invention the illumination system includes at least one radio signal receiver for detecting a person or vehicle. Such a receiver may be e.g. a receiver for detecting a RFID tag or some other remotely-read device, a receiver of a telecommunication system base station, or some other receiver which detects signals from a mobile station. For example, a receiver for detecting a RFID tag can detect the presence of a pedestrian at a site where people must carry a pass containing a RFID tag.

Furthermore, this radio signal receiver may be adapted to detect signals from remotely-read devices or radio transmitters located in vehicles. Such detection of a device located in a vehicle is especially advantageous in the case of electric cars, for example, because electric cars are so quiet that pedestrians may not necessarily notice when one is in the vicinity. In such a case the illumination system can warn the pedestrian about an approaching electric car. A telecommunication system base station receiver or another receiver detecting signals from a mobile station is suitable for detecting pedestrians and cyclists, for example, because almost everyone carries a mobile phone nowadays. Such a receiver can detect a pedestrian or cyclist farther away than a passive infrared detector, for instance, which may be very advantageous in certain applications.

In an advantageous embodiment of the invention the system may use the traffic light control signal as its control signal. For example, the system may illuminate the pedestrian crossing when a red light is on for motorists so that the pedestrian crossing and the traffic light are more easily observed and, on the other hand, the pedestrians can better see the crossing. On the other hand, in such an embodiment the system can be adapted so as to operate only when the traffic lights are not operating, for example.

In one advantageous embodiment of the invention the system is adapted to control the traffic lights. For example, as the system detects a pedestrian it can make the traffic lights to show red light to vehicle drivers and green light to pedestrians. A fairly common solution nowadays is to have a pushbutton for pedestrians for controlling the traffic lights. A system according to some embodiments of the invention can replace such a pushbutton arrangement with an automatic arrangement. In one advantageous embodiment of the invention the system further includes an audible signal device by means of which the system can use audible signals to indicate to pedestrians whether or not the street can be crossed. For example, the system may sound a warning if it simultaneously detects both a pedestrian and a vehicle approaching at a high speed. Furthermore, in an embodiment in which the system is implemented in conjunction with traffic lights, the system may produce an audible signal when the green light is on for pedestrians.

Advantageous embodiments of the invention are presented in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS Advantageous embodiments of the invention will be described below a little more closely, referring to the accompanying drawings in which

Figs. 1A to 1 B show an example of an illumination device according to an advantageous embodiment of the invention, Fig. 2A shows a cross section of an example of an illumination device according to an advantageous embodiment of the invention,

Fig. 2B shows an example of a light source and light conductor of an illumination device according to an advantageous embodiment of the invention,

Fig. 3A shows an example of an illumination pattern of an illumination device according to an advantageous embodiment of the invention,

Fig. 3B shows a top view of a cross section of an example of an illumination device according to an advantageous embodiment of the invention, ^'■ >

Figs. 4A to 4B shows an example of an illumination system comprising a plurality of illumination devices according to an advantageous embodiment of the invention, Fig. 5 shows an example of a block diagram of an illumination system according to an advantageous embodiment of the invention,

Fig. 6 shows an example of structure for illuminating a traffic sign according to an advantageous embodiment of the invention,

Fig. 7 shows some alternative locations of the light-emitting parts in the device body according to advantageous embodiments of the invention, and ,

Figs. 8A to 8B show some alternatives for determining the direction and/or speed by means of two passive infrared detectors according to an advantageous embodiment of the invention. MORE DETAILED DESCRIPTION OF THE DRAWINGS

Fig. 1A shows an example of an illumination device 100 viewed straight from the side, and Fig. 1 B shows a perspective view of the same illumination device 100 in accordance with an advantageous embodiment of the invention. The illumination device comprises at least a device body 101 the superterranean portion 101a of which may be made of elongated metal portion, such as steel portion, for instance, and the underground portion 101 b of which may be formed of concrete or such, for example, keeping the illumination device in an upright position.

In addition, the illumination device 100 comprises at least one first light-emitting part 102 and at least one second light-emitting part 103, where the second light- emitting part functions as a warning light e.g. for motorists, alerting them about a pedestrian in the vicinity of the illumination device. Furthermore, the illumination device 100 may also include, especially in conjunction with the second light- emitting parts functioning as warning lights, passive light-reflecting means 104, such as a reflective band. Furthermore, the first light-emitting part (and possible optical means in connection therewith) are advantageously arranged so that the emitted beam of light is narrow and is directed substantially obliquely downwards of the horizontal plane.

In one embodiment, the illumination device further comprises a means for activating the operation of the illumination device, such as a light-dependent switch or motion detector 105. The motion detector 105 is, adapted to detect pedestrians in the vicinity of the illumination device, for example. In addition the illumination device may, also include a manually operated switch 106 to activate the illumination device.

Fig. 2A shows a cross section of the device body 101 of an illumination device 100 according to an advantageous embodiment of the invention. The exemplifying illumination device 100 shown in Fig. 2 comprises a source of light 201 , such as a light-emitting diode 205, located e.g. in connection with a second light-emitting part 103 so that the light produced by the source of light 201 is conducted into the light- emitting part and, further, out of the device via optical means such as prisms, mirrors and/or lenses 202, 206, as well as an optical element 208 (Fig. 2B). It should be noted that the source of light may be located in the illumination device 100 also at some other point than that shown in Fig. 2A, e.g. in the base of the illumination device.

Fig. 2B shows, as an example, a source of light 210 and an optical element 208 of an illumination device 100 in an advantageous embodiment of the invention, where the source of light comprises at least one light-emitting diode 205 to produce the light, and where the light-emitting diodes are located on a support means 207. The source of light 210 in the illumination device advantageously includes at least one light-emitting diode 205 per each sector 21 1 in the light- emitting part, and an optical element 208 to direct the light out of the illlumination device at a given sector. Thus it is possible to produce a desired illumination pattern by turning on and off and/or dimming the LEDs, as substantially only those sectors the LEDs of which are on are emitting light outside the illumination device. It should be noted that between the sectors there may be light-blocking means 209 which block out the light at that point in the illumination device and especially between sectors. In an embodiment of the invention, the light-blocking means 209 may be implemented by an air gap or some other weakly transparent material such as black polycarbonate acrylonitrite butadiene styrene (PC ABS), for instance. In an embodiment of the invention, the element 210 of the illumination device shown in Fig. 2B may in itself constitute a second light-emitting part in the illumination device, reference number 103 in Figs. 1A and 1 B, for example.

The second light-emitting part (and possible optical means in connection therewith) shown in Figs. 2A and 2B are advantageously arranged such that the illumination angle 203 is appropriate and limited to the eye height of vehicle drivers and that the light is directed essentially downwards 204 of the horizontal plane thus minimising glare to vehicle drivers.

Fig. 3A shows as an example a top view of a horizontal illumination pattern 301 of an illumination 100 device according to an advantageous embodiment of the invention. Fig. 3B shows a top view of a cross section of an illumination device 100 according to an advantageous embodiment of the invention, where the cross section depicts the upper part of the device body of the illumination device, essentially the second light-emitting part (reference number 103 in Figs. 1A and 1 B, for example). In the embodiment of Fig. 3B the light-emitting diodes 205 are represented by dashed lines and are located esssentially under the optical element 208. Also depicted are the light-blocking means 209 and illumination pattern 301 . It should be noted that the size and shape of the illumination pattern can be changed e.g. during operation by switching on and off and/or dimming light-emitting diodes as described in connection with Fig. 2B. Fig. 4A shows, as an example, an illumination system 400 comprising a plurality of illumination devices 100 in accordance with an advantageous embodiment of the invention, where the illumination devices 100 are arranged so as to improve the safety of an intersection of two different traffic routes, a first traffic route 401 and a second traffic route 402. Advantageously the illumination devices 100 in the illumination system 400 are arranged in such a manner that the device bodies form a mechanical barrier preventing vehicles 403 advancing along the first traffic route 401 from entering the second traffic route 402.

In one embodiment, the illumination system 400 may also include a separate means 404 for detecting a vehicle advancing along the first traffic route. The system 400 may also include a separate means 405 for detecting a pedestrian approaching along the second traffic route. The means 404, 405 may be any prior- art motion detection means equippped with a power source, such as a battery, wind-powered generator, solar panel and/or means for connecting to the electricity mains. However, it should be noted that also the illumination devices 100 may include motion detection means, in which case separate motion detection means 404 and/or 405 are not necessarily needed.

Fig. 4B shows the illumination system 400 depicted in Fig. 4A magnified, where the illumination devices 100 in the illumination system 400 are located at a pedestrian crossing so that they mechanically prevent cars from entering the pavement.

The first light-emitting part 102 at the lower part of the illumination device 100 is advantageously adapted to emit light 406 on the pedestrian crossing in the direction of the intersection with the purpose of illuminating the route across the intersection. Additionally the illumination device 100 comprises at least one second light-emitting part 103 arranged in the illumination device advantageously above the first light-emitting part 102. The purpose of the light 407, which advantageously is a blinking light, emitted by the second light-emitting part 103 is to alert a motorist 403 advancing along the first traffic route 401 about a pedestrian at the intersection. Additionally the illumination devices 100 may include motion detection means 105 for detecting a pedestrian approaching the intersection. The motion detection means 105 may be implemented using technology mentioned in this document, such as an infrared barrier 105a, for example.

Fig. 5 shows, as an example, a functional block diagram 500 of an illumination system 400 and its illumination devices 100 in accordance with an advantageous embodiment of the invention, where the illumination system 400 includes a system control centre 501. In one embodiment, the control centre 501 includes at least a data communication means 502 for communicating with the illumination devices 100 and for gathering data from them as well as a data communication means 503 for communicating with a third party, such as the party responsible for the system. Such communication can be used for controlling the illumination system and adjusting the illumination system parameters, for example. In addition, the control centre may include means for monitoring the environmental conditions, e.g. weather and lighting metering devices 504 as well various means 505 gathering data from motion detectors (for monitoring the amount of traffic, speed of traffic, direction of traffic or other quantities related to traffic, for instance), and a data processing means 506 for processing the gathered, received and/or transmitted data as well as for controlling the operation of the illumination devices 100 on the basis of the processed data, e.g. for switching lights on and off, synchronising the blinking of lights and adjusting the brightness of the lights. The control centre may also include a power source 507a of its own and/or an external power source 507b. The control centre may also be adapted to forward to a third party via the data communication means 503, information collected from the measurement devices 504 and from the means 505 gathering data from the sensors. Such a third party may be e.g. the city traffic centre or some other similar place where the traffic is controlled or monitored. The data communication means 503 may comprise e.g. a wired or wireless modem, data network interface, mobile network terminal or some other means designed to relay data communications. In one embodiment, the means mentioned above can be used for gathering status information from the illumination devices and/or monitoring environmental conditions and controlling the illumination devices in the system on the basis of the status information and/or environmental conditions.

An illumination device may include e.g. a data communication means 508, data processing means 509, control means 510 for a motion detector, light-independent switch and/or mechanical switch, and a control means 51 1 , 512 for the light sources (possibly separate means for both the first and the second light-emitting parts). Additionally the illumination device may also include a power source 513 of its own, as described elsewhere in this document. In one advantageous embodiment of the invention the illumination device may further use the control centre 501 and data communication means 503 to transmit a sound signal, whereby the illumination device advantageously also includes a microphone or corresponding sound reception means and/or a loudspeaker or corresponding sound reproduction means. The illumination device may e.g. include a switch, pushbutton or such for generating an emergency call, whereby the illumination device can be used for requesting help and, by means of voice communication, giving a more detailed account of the situation.

Fig. 6 shows a structure for illuminating a sign, such as a traffic sign, for instance, in accordance with an advantageous embodiment of the invention. The structure comprises at least a base plate 601 , reflective layer 602, mask 603, light conductor element 604, and a light source 605. The base plate 601 may be made of metal, plastic, plywood, or a composite material, for example. The purpose of the reflective layer 602 is to reflect the incident light in order to enchance the visibility of the sign. It is obvious to a person skilled in the art that many different reflective materials known from the prior art are applicable here. The purpose of the mask 603 is to form the pattern, patterns and/or texts on the sign. There may be a plurality of mask layers 603 which could be of different colours or different transparency, for example. Advantageously the light source 605 comprises one or more light-emitting diodes but other prior-art lamps, such as fluorescent tubes or incandescent light bulbs, could also be used.

The purpose of the light conductor element 604 is to conduct the light from the light source 605 onto the surface of the sign in order to illuminate it. In a structure according to an advantageous embodiment of the invention, shapes are formed on at least one surface of the light conductor element to cause the light which is propagating inside the light conductor element to scatter, refract or reflect towards the mask 603 and reflective layer 602 from where the light is reflected so that it can be seen by a potential viewer.

The shapes formed on the surface of the light conductor element may be either on the front surface 604a or on the rear surface 604b or on both the front and rear surfaces 604a, 604b. The shapes can be of various kinds and sizes and can produce the change in the direction of propagation of the light through reflection, refraction or scattering, or through interference, for example. The shapes could be e.g. triangular, rectangular, lozenge-shaped or they could have some other shape, but advantageously the shapes are such that they cause the light coming from the light source 605 to change its direction of propagation towards the reflective layer 602. It is obvious to a person skilled in the art that the sizes of the shapes in the direction of the surface 604a, 604b as well as in the direction perpendicularly against the surface and the cross-section profile may be very different in different applications of the invention/ depending on how the direction of the propagation of light is produced. Furthermore it is obvious that the surface 604a, 604b where the shapes are formed is substantially an interface between two materials which have different refractive indices. These materials may simply be plastic and air, for example. These materials may also both be solid materials, say plastics having different refractive indices, on the interface of which the shapes which change the direction of the light are formed, in which case the shapes would be protected against environmental effects such as rain, dirt and mechanical wear which could negatively affect the orientation of light.

Fig. 7 shows a device body 701 according to an advantageous embodiment of the invention with different numbers of light-emitting parts 702, 703, 704 at different heights. In the example case of Fig. 7, the light-emitting part 702 is for illuminating the pedestrian crossing, light-emitting parts 703 are for alerting motorists, and the higher-located light-emitting parts 704 are also for alerting motorists. In the example case of Fig. 7 the light-emitting parts 704 are located higher up so that vehicles parked close to the device body 701 will not block them from the view of motorists approaching along the road. Fig. 7 also illustrates an embodiment of the invention where the device body 701 serves as the post 701 of a traffic sign 701 , 705.

Figs. 8A and 8B illustrate advantageous embodiments of the invention where two passive infrared sensors are used for monitoring the direction and/or speed of movement of objects advancing along one traffic route, such as a route for light traffic, for instance. Fig. 8A shows a device body 801 , two passive infrared (PIR) sensors 802, 803, monitoring sectors 802a, 803a of the sensors 802, 803, and a pedestrian 804. This example represents an embodiment where the sensors 802, 803 are located in the same device body 801. As the pedestrian 804 approaches the carriageway along the light traffic route he first hits the monitoring sector 803a of the first PIR sensor 803, whereby a corresponding change occurs in the output signal of this sensor. As the pedestrian advances further he hits the monitoring sector 802a of the second PIR sensor 802, whereby a change occurs in the output signal of the second sensor. Observing the time and/or shape differences of the signals from these two sensors it is possible to determine the direction of approach of the pedestrian 804.

Fig. 8B illustrates a similar sequence of events as Fig. 8A but in an embodiment of the invention where the PIR sensors 802, 803 are located in different device bodies 801. As the pedestrian 804 approaches the carriageway along the light traffic route he first hits the monitoring sector 803a of the first PIR sensor 803, whereby a corresponding change occurs in the output signal of this sensor. As the pedestrian advances further he hits the monitoring sector 802a of the second PIR sensor 802, whereby a change occurs in the output signal of the second sensor. Observing the time and/or shape differences of the signals from these two sensors it is possible to determine the direction of approach of the pedestrian 804. Only a few embodiments of the solution according to the invention were described above. The principle according to the invention, as regards e.g. implementation details and field of application, may naturally be modified within the scope of the invention defined by the claims. In particular, the method can be applied in intersections of routes intended for automobiles and routes intended for light traffic but also in other intersections of two traffic routes of different types such as intersections of railways and other traffic routes, for example. Additionally it should be noted that while optical means in general and lenses, for example, were mentioned above, the lenses, for instance, could be special reflective Fresnel-type and diffractive lenses.