FIELD OF THE INVENTION

The present invention concerns an illumination device usable in public or private lighting plants, for example to illuminate transit areas such as roads, pavements and/or more generally urban or extra-urban or residential areas.

BACKGROUND OF THE INVENTION

In the field of public or private lighting, it is known to use illumination devices that can supply conditions of adequate visibility, both to facilitate the traffic of vehicles along the street, and also for pedestrians on the pavement, or urban centers.

One of the main objectives of public lighting plants is to illuminate determinate areas to the desired degree. In particular, one objective is to supply an adequate degree of luminosity to guarantee road safety, so as to reduce the possibility of accidents caused by limited visibility.

To be able to supply adequate lighting conditions, the illumination devices used must have characteristics of light efficiency, great reliability, long duration and good functioning performance.

Illumination devices are known that comprise one or more light sources, such as for example incandescent lamps, gas discharge lamps, induction lamps and LED lights (Light Emitting Diode).

Illumination devices comprise a support base, in which the light source or a plurality of light sources are installed, protected by a cover made of light- transparent material, which reflects as little as possible and through which the flow of light passes.

In order to have a correct functioning of the illumination device, it is necessary to provide maintenance interventions to prevent a possible deterioration of the light sources and/or to keep the cover made of transparent material clean.

Indeed, the external surface of the cover is subject to atmospheric dust or other dirt, which can at least partly attenuate the intensity of the light transmitted, that is, the light intensity that they allow to transit, which means that the regulations concerning minimum lighting are not respected, and therefore leads to problems of poor visibility that may not be detected by the system managing the public lighting.

Furthermore, it can happen that one or more light sources in the illumination device can deteriorate, or not function correctly.

Illumination devices are generally installed at a few meters above the ground, so that maintenance interventions are not very easy and the tendency in this field is to try to limit them as much as possible.

Generally, to guarantee the correct functioning of the illumination devices, programmed maintenance interventions are provided, established according to the average life of the light sources, but these may not be sufficient to guarantee the required luminosity and visibility conditions required by the regulations.

For example, it can happen that in some illumination devices, for example positioned in correspondence with traffic lights or zones with a greater concentration of pollutant dust, the transparent covers tend to get dirty more frequently, preventing the passage of a part of the light.

Furthermore, if the cover is subject to dust and/or other dirt after a maintenance intervention, there is a risk that the illumination device could remain inefficient for a long period of time before the correct functioning is reestablished.

Document WO-A-2014/078907 describes a lamp with a lens through which the light is transmitted. The lamp has at least one sensor to detect the dirt and/or contamination of the lens, and possible other sensors to detect other conditions inside or outside the lamp. The data detected are transmitted to a controller for maintenance.

One purpose of the present invention is to supply an illumination device that allows to verify continuously the possible deterioration in the light of the illumination device and/or its functioning efficiency.

Another purpose of the present invention is to supply an illumination device that is able to guarantee the required luminosity even when the cover is dirty or stained.

Another purpose is to supply an illumination device that allows to carry out targeted maintenance interventions when they are actually necessary.

Another purpose is to supply an illumination device that that is simple but that guarantees the required visibility. The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, an illumination device is provided to illuminate urban or extra-urban areas, comprising a support base in which one or more light sources are installed, able to emit corresponding light beams to illuminate a determinate area, or surface.

The support structure is associated with a pole, or support cables, or other support structure, in order to be positioned suspended at a determinate height with respect to the surface to be illuminated.

The support structure is provided with a housing seating, in which the light sources are installed, closed toward the area to be illuminated by a protective cover made of a light- transparent material.

Examples of light transparent materials can be glass, tempered glass, transparent plastics, optical polymers, or other suitable materials. There can be electric and/or electronic components inside the support structure to power the one or more light sources.

According to one aspect of the present invention, the illumination device comprises a reflection sensor located in the volume defined between the housing seating and the protective cover and configured to detect a reflected radiation from the protective cover in the housing seating.

The detection of a reflected radiation inside the housing seating allows to evaluate the state of the protective cover. In particular, it allows to evaluate if the surface of the protective cover facing toward the outside and/or facing toward the inside is clean or not. If it is clean, almost all the radiations and light beams emitted from inside the housing seating toward the protective cover are transmitted to the outside, and in the housing seating there is possibly only one minimal reflected radiation determined by the natural reflection of the protective cover. On the contrary, if it is not clean, or in a dirty state, there is a reflected radiation inside the housing seating, whose intensity depends on the lack of cleanliness, or the dirtiness, of the protective cover.

According to some embodiments, the reflection sensor comprises a transmitter configured to emit a radiation incident on the protective cover and a receiver configured to receive a reflected radiation from the protective cover correlated to the emitted radiation.

According to some embodiments, the radiation emitted from the transmitter and the reflected radiation received by the receiver are infrared radiations.

According to some embodiments, the transmitter can emit an infrared radiation modulated to a frequency chosen so as to screen both the light pollution of the light sources outside the illumination device, and also the light beams emitted by the light sources.

According to some embodiments, the reflection sensor is positioned adjacent to the protective cover, and shielded from the light beams emitted by the light sources so that the receiver receives only a reflected radiation deriving from the radiation emitted by the transmitter.

The reflection sensor can monitor, continuously or at pre-established intervals, the reflected radiation in the housing seating. In this way, it is possible to maintain the functioning efficiency of the illumination device monitored, and in particular the level of cleanliness of the external surface, or possibly also the internal surface of the protective cover, allowing to perform targeted maintenance interventions when these are necessary.

According to possible solutions, the reflection sensor cooperates with a control unit, configured to evaluate the data received by the receiver, such as the intensity and the wave form of the reflected radiation, and generate corresponding signals and/or alarms.

In particular, the control unit can be configured to process data relating to the intensity and wave form of the reflected radiation detected by the reflection sensor, to compare them with reference parameters and to generate possible signals and/or alarms in order to notify the need for maintenance interventions on the protective cover depending on the result of the comparison.

According to other embodiments, the control unit can be configured to modify, for example intensifying, the power to the light sources as a function of the data received and processed, in order to compensate the possible losses of light emission due to an unclean and/or non-integral state of the protective cover.

The control unit, in particular, on the basis of the information on the reflected radiation, can determine the percentage of light effectively transmitted to the outside of the protective cover with respect to the light emitted from the light sources. If the percentage of light transmitted is less than a reference level, the control unit can command a power unit of the light sources to increase the pilot current and therefore the intensity, depending on the loss of transmission deriving from the unclean state of the protective cover.

According to some embodiments, the control unit can send the data received by the reflection sensor to a management and control station, configured to process the data received and, as a function of said data, to determine whether or not it is necessary to proceed with the maintenance of the illumination device.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

- Fig. 1 is a schematic and perspective view of an illumination device in accordance with embodiments described here;

- fig. 2 is a partial view along the section plane π in fig. 1 of the illumination device in an operating condition;

- fig. 3 is a partial view along the section plane π in fig. 1 of the illumination device in a different operating condition.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

We shall now refer in detail to the various embodiments of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.

Embodiments described here concern an illumination device 10 usable in public lighting plants, for lighting roads, pavements and/or urban or extra-urban areas in general, to supply conditions of adequate visibility both for vehicular traffic and for pedestrians.

The illumination device 10 comprises a support base 12 suitable to support one or more light sources 14, each configured to emit a respective light beam to illuminate a determinate zone or surface.

According to a preferred embodiment, the light sources 14 are LED lights (Light Emitting Diodes), which are long-lasting, low-consumption and have no pollutant substances for the environment.

According to possible variant embodiments, the light sources 14 can be of different types, such as for example incandescent lamps, gas discharge lamps, induction lamps or other types.

The support base 12 is associated with a support structure 16, for example a pole, or support cables, to keep the support base 12 suspended with respect to the surface to be illuminated, for example at a height comprised between about 6 m and about 10 m.

According to some embodiments, the support base 12 comprises a housing seating 18 in which one or more light sources 14 can be installed.

The housing seating 18 is closed by a protective cover 20 made of material that is transparent to light, with a function of protecting the light sources 14. The protective cover 20 has an internal face 20a facing toward the housing seating 18, and an external face 20b, opposite the internal face 20a and facing toward the outside.

According to some embodiments, the protective cover 20 can be made of material and/or with a thickness suitable for the passage of the light beams emitted by the light sources 14. Examples of suitable materials can be glass, tempered glass, transparent plastics, optical polymer or other suitable material.

In particular, the protective cover 20 can be made in such a way that it is not very, or not at all, reflective, so that the light beams emitted by the light sources 14 are almost totally transmitted outside the protective cover 20.

According to one aspect of the present invention, the illumination device 10 comprises a reflection sensor 22, positioned inside the housing seating 18 and configured to detect a reflected radiation RR reflected by the protective cover 20 inside the housing seating 18.

According to some embodiments, the reflection sensor 22 is positioned facing toward the protective cover 20, oriented in the same direction as the light sources 14.

According to possible solutions, screening elements can be provided, not shown here, to protect the reflection sensor 22 from the light beams emitted by the light sources 14, so that the light beams do not interfere with the detection of the reflected radiation RR.

According to possible solutions, the reflection sensor 22 can be positioned at the center of the housing seating 18, to detect the radiation reflected by the protective cover 20 in the central zone thereof.

According to possible variant embodiments, the reflection sensor 22 can be positioned in a corner, and/or in proximity to an edge of the housing seating 18. According to other variants, two or more reflection sensors 22 can be provided, positioned at different points in the housing seating 18, each configured to detect a specific radiation reflected by the protective cover 20 in correspondence with the zone where they are positioned.

According to some embodiments, the reflection sensor 22 comprises a transmitter 24, configured to emit and transmit a ray or a radiation RE toward the protective cover 20, and a receiver 26, configured to detect a possible ray or radiation RR reflected by the internal face 20a of the protective cover 20 toward the inside of the housing seating 18, correlated to the emitted radiation RE.

According to some embodiments, the transmitter 24 can emit a radiation RE with an angle of incidence comprised between about 20° and about 120°.

According to variant embodiments, the emitted radiation RE can have an angle of incidence comprised between about 50° and about 90°.

According to possible implementations, the reflection sensor 22 is positioned adjacent to the protective cover 20, for example at a distance comprised between about 10 mm and about 30 mm, so as to have a limited field of action and therefore only detect the reflected radiation RR with an angle of reflection equal and opposite to the angle of incidence.

According to some embodiments, the radiation emitted RE is a radiation in the infrared field. Infrared radiation has the advantage that it is powerful, not easily influenced by environmental light and not very sensitive to color.

According to some solutions, the emitted radiation RE has a wavelength comprised between about 700 nm and about 100 μηι.

According to possible solutions, the wavelength of the radiation emitted RE can be comprised between about 880 nm and about 950 nm.

According to possible variant embodiments, the wavelength of the emitted radiation RE is comprised between about 890 nm and about 935 nm.

According to some embodiments, the wavelength can be chosen depending on the type of material that the protective cover 20 is made of.

According to these embodiments, the reflected radiation RR detected by the receiver 26 is also a radiation in the infrared field, correlated to the emitted radiation RE.

According to some embodiments, the transmitter 24 is configured to emit a radiation RE modulated at a determinate frequency, chosen so as to screen both the light pollution of radiations emitted by the light sources outside the illumination device 10, and also those emitted by the light sources 14.

According to possible solutions, the modulation frequency can be comprised between about 30 kHz and about 40 kHz.

According to possible variant embodiments, the modulation frequency can be comprised between about 32 kHz and about 38 kHz.

In this way, the receiver 26 effectively detects the reflected radiation RR reflected by the protective cover 20, correlated to the emitted radiation RE emitted by the transmitter 24, without being influenced by the light beams emitted by the light sources 14 or other light sources outside the illumination device 10, such as the sun, stars or light pollution in general.

In one operating condition where, for example, the external face 20a of the protective cover 20 is clean, described for example with reference to fig. 2, the radiation RE emitted by the transmitter 24 is almost completely transmitted to the outside of the protective cover 20, so that no reflected radiation RR reaches the receiver 26. In this specific case too, all the light beams emitted by the light sources 14 are efficiently transmitted toward the outside of the protective cover 20, and therefore supply the required conditions of luminosity.

According to some embodiments, also if the protective cover 20 is clean, the internal face 20a can reflect a minimum fraction of reflected radiation RR, which can easily be calculated as a function of the emitted radiation RE and of the material that the protective cover 20 is made of, and can therefore be compensated.

In a different operating condition, described for example with reference to fig. 3, the external face 20b of the protective cover 20 can be exposed to atmospheric dust, pollution or other dirt, so that a patina 28 can form that at least partly limits the passage of the radiations and the light beams toward the outside.

In this case, the receiver 26 detects the reflected radiation RR reflected by the protective cover 20 in the housing seating 18. The reflected radiation RR grows as a function of the thickness and/or size of the patina 28 of dirt on the protective cover 20, so that by measuring the intensity of the reflected radiation RR it is possible to determine when it is necessary to carry out a maintenance intervention.

According to some embodiments, the reflection sensor 22 cooperates with a control unit 30, configured to process data relating to the intensity and wave shape of the reflected radiation RR detected by the reflection sensor 22, and to compare them with reference parameters and to generate possible signals and/or alarms to notify the need for maintenance interventions for the protective cover 20, according to the result of said comparison.

According to some embodiments, the reflection sensor 22 can comprise the control unit 30, or be connected to it.

According to some embodiments, the reflection sensor 22 can analyze the reflection of the protective cover 20 continuously or at established intervals of time, and when it exceeds a determinate threshold value, the control unit 30 detects the presence of the patina 28 and then signals this unclean condition of the protective cover 20.

According to some embodiments, the control unit 30 can comprise a memorization element 32, in which reference parameters can be memorized, comprising at least a value of maximum intensity of reflected radiation and/or intensity and wave form of the emitted radiation RE.

According to some embodiments, the control unit 30 comprises comparison means 34 configured to compare the intensity and/or wave form of the reflected radiation RR with the reference parameters memorized in the memorization element 32.

According to possible embodiments, the control unit 30 can be configured to determine if the protective cover 20 is to be cleaned to eliminate the patina 28 of dirt, and/or if the protective cover 20 has to be replaced because it is broken or damaged.

In some embodiments, the control unit 30 can recognize if a cleaning intervention or a replacement of the protective cover 20 is necessary, depending on the characteristics of the reflected radiation RR.

For example, the control unit 30 can generate a signal to indicate the need for a cleaning intervention when the intensity of reflected radiation RR received by the receiver 26 exceeds the maximum value of intensity memorized. The patina 28 of dirt entails an increase in the intensity of reflected radiation RR, but leaves the wave form almost unchanged, which remains identical or similar to the intensity of the emitted radiation RE.

According to other variant embodiments, the control unit 30 can generate a signal to indicate the need for an intervention to replace the protective cover 20 if the wave form of the reflected radiation RR received by the receiver 26 has suffered a deformation with respect to the wave form of the emitted radiation RE. Any possible damage to and/or breakage of the protective cover 20 entails a deformation of the wave form of the reflected radiation RR with respect to that of the emitted radiation RE.

According to some embodiments, the control unit 30 can also be configured to compensate the minimum fraction of radiation reflected by the protective cover 20 depending on the material that it is made of, for example during the installation and/or inspection phases of the illumination device 10. In this way it is possible to calibrate the receiver 26, and in general the reflection sensor 22, to an ideal zero value with regard to the natural reflection of the protective cover 20 when it is clean.

According to other embodiments, the control unit 30 can be connected to a power unit 31 of the light sources 14. According to these embodiments, the control unit 30 can be configured to modify the power to the light sources 14, for example LEDs, according to the data received from the reflection sensor 22, so as to compensate the losses due to an unclean and/or damaged condition of the protective cover 20, and/or to possible cracks or other type of damage thereof.

According to some embodiments, it can be provided that the light sources 14 are initially powered by a pilot current so as to have a light intensity comprised between about 50% and 80% of the maximum light intensity.

The control unit 30 can determine the percentage of light actually transmitted outside the protective cover 20 with respect to the light emitted by the light sources 14 based on the information on the reflected radiation RR, and can compare it with reference parameters relating to an ideal luminosity emitted by the illumination device 10.

If the percentage of light transmitted is less than the level of luminosity required, the control unit 30 can command the power unit 31 to increase the pilot current to the light sources 14, and hence their intensity, so as to restore the required luminosity conditions.

According to some embodiments, the control unit 30 can modify the pilot current to the light sources 14 according to reference values memorized in the memorization element 32, for example determined by an initial calibration of the illumination device 10 and/or as a function of the application of the illumination device 10.

According to some embodiments, the control unit 30 can communicate with the power unit 31 by a Dali 1..10 communication protocol or suchlike.

According to some embodiments, the control unit 30 can be connected to and communicate with a management and control station 36, configured at least to receive the signals generated by the control unit 30 relating to the interventions to maintain and/or replace the protective cover 20, and possibly to manage the necessary maintenance interventions.

According to other embodiments, the management and control station 36 can receive directly from the control unit 30 the information relating to the reflected radiation RR and can process it to determine whether or not a maintenance intervention is required by the respective illumination device 10.

According to some embodiments, the management and control station 36 can be positioned at street level, integrated in the support structure 16, or can be positioned remotely.

According to some embodiments, the management and control station 36 can be connected to and/or integrated in a traditional management system of a public and/or private lighting plant.

Between the control unit 30 and the management and control station 36 communication and data transmission means 38 can be provided.

The communication and data transmission means 38 can be the cable type, wireless, radio, infrared or based on GSM and/or GPRS network protocols.

According to other embodiments, the communication and data transmission means 38 can comprise Radio Frequency systems, for example Wi.Fi, ZigBee, LO.RA and suchlike.

According to other embodiments, the management and control station 36 can be connected to a plurality of control units 30 of respective illumination devices 10, and can determine if/when it is necessary to carry out a maintenance intervention, also as a function of the information received from other control units 30 with regard to the respective illumination devices 10.

It is clear that modifications and/or additions of parts may be made to the illumination device as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of illumination device, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.