WO2013098799A1

WO2013098799A1 - A method and an apparatus for lighting an area intended for stay and/or the movement of persons and vehicles, in particular road tunnels

Info

Publication number: WO2013098799A1
Application number: PCT/IB2012/057847
Authority: WO
Inventors: Romolo BECCHETTI; Alessandro Pini; Francesco VIVALDI
Original assignee: Becchetti Romolo; Alessandro Pini; Vivaldi Francesco
Priority date: 2011-12-31
Filing date: 2012-12-31
Publication date: 2013-07-04
Also published as: ITPI20110147A1; ITPI20120120A1; EA201491279A8; EA026832B1; EA201491279A1; MA35879B1; EP2798014A1

Abstract

A method for lighting with a predetermined illuminance an environment (11,12) intended for the stay and/or for the passage of people and/or vehicles, comprising steps of selecting and installing in the environment (11,12) at least one passive lighting element (13) comprising a photoluminescent pigment, typically a material of formula Al_xSr_yCa_(1-y)O_z:Eu,Dy and/or an Europium and/or Dysprosium-doped alkaline-earth aluminate, in particular a material of formula SrAl₂O₄:Eu,Dy or SrAl₂O₄:Eu,Dy,B, adapted to emit a photoluminescent light flux (13') when exposed to a primary light flux (19'). In an aspect of the invention, the environment (11,12) has at least one electrically suppliable active lighting body (19) or a pre-existing electric lighting installation, which is adapted to generate the primary light flux (19'), and the method provides supplying an adjusted electric power to at least one active lighting body (19) to generate the primary light flux (19') that is summed to the photoluminescent flux (13'), producing the required illuminance. According to another aspect of the invention, the method provides steps of selecting the at least one active lighting body (19) in such a way that, by supplying it with a predetermined electric power, the primary light flux (19') and the luminescent light flux (13') produce together the required illuminance value. The method remarkably reduces the lighting energy consumptions as well as the costs of the lighting installation. In an exemplary embodiment, the environment is a road or motorway environment (11,12), for example a or pedestrian road tunnel (11). The passive lighting element (13) can be a photoluminescent stripe (13) arranged on the wall (10, 10') and parallel to the ground (9), having a predetermined width (H),

Description

TITLE

A METHOD AND AN APPARATUS FOR LIGHTING AN AREA INTENDED FOR STAY AND/OR THE MOVEMENT OF PERSONS AND VEHICLES, IN

PARTICULAR ROAD TUNNELS DESCRIPTION

Field of the invention

The present invention relates to a method for lighting, permanently or during the night, areas like roads and motorways such as tunnels, underground stations and the like, underground car parks and so on.

Furthermore, the invention relates to an auxiliary lighting element for such a lighting apparatus, and to a method for manufacturing this auxiliary lighting element.

Technical problem

The permanent or night lighting of such environments as road tunnels and other road environments, underground stations, underground car parks, and the like, is normally carried out by means of electric lighting installations that involve a relevant energy consumption. Fluorescent lamps, usually sodium vapour lamps and, more recently, LED lamps, are among the most used types of lighting sources.

Energy consumption is a particularly important aspect for road and motorway tunnels, since in this case they are concerned also in daytime. In the case of road and motorway tunnels, in order to increase the visibility of the roadway edge and to reduce the lighting energy costs, the wall of the tunnel, or of part of it, is painted. Normally, a white paint is used, because it has better reflection properties. This makes it possible to save only a small amount of energy.

A significant contribution to the consumption and to the costs of the lighting installation for a tunnel is given by the so-called reinforced-lighting zones, i.e. by the entry zones, where the regulations require more intense local lighting conditions to help the human eye to adapt when passing from the outside daylight to the artificial light within the tunnel. In other words, a lighting power must be installed in the entry zones higher than the other zones of the tunnel. More in detail, the lighting bodies are installed at shorter mutual distance, and/or higher lighting powering bodies are installed, than in the inner portions of the tunnel. Typically, the length of the reinforced-lighting portion in motorway tunnels is about 220-240 m, taking into account the adaptation time normal human eyes, and assuming a vehicle close to the maximum allowed speed. For example, in a motorway this speed may be about 130 Km/h.

Furthermore, if a conventional lighting installation is used for lighting tunnels, portions of roads as well as other dark environments, in the case of a sudden black-out, and if a possible electrical continuity or emergency system is out of service, a darkness condition may occur, which involves a serious danger for the users, even if the wall of the tunnel, a road element or a portion of a dark environment is painted. Furthermore, the conventional painting cannot effectively highlight the walls if an electric lighting installation is not available.

EP0710709A1 describes a phosphorescent material comprising, in its most general form, a matrix of formula 1- xAI204-x, where M is at least one metal selected among calcium, strontium and barium, and x is a number different from zero, the matrix comprising Europium such as an activator and, as a co-activator, at least one element that may be Dysprosium. It also relates, to a method for imparting a luminescent feature to an object, such as a safety signalling element, a road sign, a guard-rail, by applying a substrate of the above phosphorescent material. However, the application of the luminescent substrate is only used to make the object more visible while driving.

EP1746078A1 describes a luminous product obtained by applying alternate layers of luminous and glass particles on a glass base that is arranged on a ceramic base, and by providing an outer glass protective layer. EP1746078A1 also relates to elements of indication of escape way signs made of the above luminous produced product.

JP2004176457 describes a luminous floor material and to allow a person, in an emergency situation, to be safely guided towards a safety exit, even if an emergency electric supply is out of service or missing. A groove is formed on an exposed face of the material of the floor material, and a linear luminous layer is arranged on the primer of the groove.

JP2005205258 relates to a method for making a luminous coating film for forming a temporary coating without smell and safety problems, in which the use of a specific heating/drying system is provided. A coating base material, comprising a non-solvent type irradiation-curable resin, is applied along with a photopolymerization initiator and with a luminous pigment, and is then irradiated to form a base coating film. Then, a coating material is applied that comprises a non-solvent type irradiation-curable resin, a photopolymerization initiator and a luminous pigment, in which the ratio between the resin and the pigment is set between 2 and 0.25.

Summary of the invention

It is therefore an object of the invention to provide a method for lighting an environment intended for the stay and/or for the passage of people and vehicles, in particular road tunnels, or other road environments, which allows a significant reduction of energy consumptions with respect to the conventional electric lighting installations, providing a same illuminance in the environment.

It is also an object of the invention to provide a method and a lighting apparatus that involves installation and maintenance costs lower than the costs of the prior art installations, providing a same illuminance in the environment.

It is also an object of the invention to provide such a method and apparatus that allows a useful residual lighting if the electric supply of active lighting bodies of the apparatus is missing.

It is also an object of the invention to make a passive lighting element, in particular one that can be used to reach the above objects.

In a first aspect of the invention, these and other objects are achieved by a method for lighting with a predetermined illuminance value an environment intended for the stay and/or for the passage of people and/or vehicles, the environment having at least one electrically suppliable active lighting body, the active lighting body generating a primary light flux,

said method comprising the steps of:

selecting at least one passive lighting element comprising a photoluminescent pigment, the at least one passive lighting element configured for emitting a photoluminescent light flux responsive to an excitation by the primary light flux;

installing the at least one passive lighting element in the environment, at a position arranged to receive the primary light flux; supplying at least one part of the at least one active lighting body with an electric power such that the at least one active lighting body generates the primary light flux that, summed to the photoluminesoent light flux, produces the predetermined illuminance value.

In other words, the environment has an active lighting body or an existing electric lighting installation, which is adapted to generate a primary light flux, and the method provides a supply of electric power to the at least one active lighting body, or to a part of it, to generate the primary flux that summed to the photoluminescent flux, produces the required illuminance as the sum of an primary illuminance and of a photoluminescent secondary illuminance.

In a second aspect of the invention, the above mentioned objects are reached by a method for lighting with a predetermined illuminance value an environment intended for the stay and/or for the passage of people and/or vehicles,

the method comprising the steps of:

selecting at least one electrically suppliable active lighting body, the active lighting body configured to generate a primary light flux;

wherein the at least one active lighting body and the at least one passive lighting element are selected in such a way that, by supplying the at least one active lighting body with a predetermined electric power, the primary light flux and the photoluminescent light flux produce together the predetermined illuminance value,

installing, in the environment, the at least one active lighting body and the at least one passive lighting element, said at least one active lighting body and the at least one passive lighting element arranged at a mutual position such that the at least one passive lighting element receives the primary light flux;

supplying the at least one active lighting body with the electric power.

The advantage of the passive lighting elements that comprise a photoluminescent pigment is that they return a significant portion of the light radiation coming from the active lighting bodies, typically from an electric lighting installation. Without passive lighting elements, this radiation would be adsorbed by the structures, and therefore would be lost.

In other words, the photoluminescent pigment makes it possible to exploit more effectively the light radiation that is delivered by the active lighting bodies. This is particularly relevant in environments that are confined within walls and are permanently lighted by electric lighting installations, for example road tunnels, but also underground car parks, underground stations and places or the like.

Therefore, with such a passive lighting element it is possible to obtain a predetermined illuminance in such environments, by less light- radiation delivered by the active lighting bodies, i.e. by an electric lighting installation, if any. More in detail, under a same illuminance, it is possible to use or to install fewer lighting elements, or to use lower-lighting powering elements, or to reduce the electric power adsorbed by an existing lighting installation.

Accordingly, the method makes it possible to reduce the operating costs of the electric lighting installations, and possibly to reduce the installation costs of a lighting installation. The larger the surface of the passive lighting element or elements, the higher is the saving. In fact, the amount of photoluminescent light radiation that is returned by the passive lighting elements is proportional to the lighted area, as well as to the intensity of the light with which is lit, i.e. it is proportional to the amount of the exposed photoluminescent pigment.

Preferably, the active lighting body or bodies comprise(s) LED lighting bodies. In particular, the active lighting bodies are configured for emitting a primary light flux comprising a light in a wavelength spectrum ranging from the violet-UV to the blue.

More in detail, the at least one active lighting body is configured for emitting a primary light flux comprising a light in a spectrum of wavelength shorter than 480 nm, more in particular, shorter than 450 nm, even more in particular, shorter than 430 nm.

In alternative, the active lighting body or bodies comprise(s) halogen lighting bodies. In alternative, the active lighting body or bodies comprise(s) lighting bodies selected among metal halogenide lighting bodies, high pressure sodium lighting bodies, incandescent lighting bodies. Another advantage of the passive lighting elements that comprise a photoluminescent pigment, which appears if the active lighting bodies are broken or are switched off, is that they emit a photoluminescent or secondary light radiation for a predetermined time after the failure or in any case after switch ing-off. In normal night lighting conditions of tunnels, of other road environments and airport structures, this time is about 30 minutes, during which a good visibility level is maintained, after 30 minutes the passive lighting element or elements continue(s) to emit light, with a fading intensity.

In particular, the passive lighting element or elements can make visible the lane and/or carriageway edge, the wall of a tunnel or other side structures or any obstacle that may be lying on the carriageway, provided the blackout is lasting for less than a determined time. This occurs, in particular, if the passive lighting element or elements are suitably arranged along the road environment.

The residual lighting of the road environments after the beginning of a blackout makes it possible to limit impulsive reactions by car drivers, such as a sharp braking, which may cause accidents. Therefore, the passive lighting elements can collaborate with continuous power sources, or even replace the continuous power sources, in particular in normally intensely lighted places, such as department stores, sports places, short tunnels.

In particular, the environment that has the at least one passive lighting element is a road or motorway environment. This environment may be a carriageway or a lane, a emergency lane, as well as a park place or area. Advantageously, the passive lighting element has the shape of a stripe arranged along a side structure of the road or motorway environment, as described more in detail hereinafter.

In a particularly advantageous exemplary embodiment, the environment is a road, motorway or pedestrian tunnel. Preferably, the passive lighting element is continuously or discontinuously arranged along a wall of the tunnel, and has a surface of at least 0.5 m² per meter of length of the tunnel. In particular, the lighting body has a surface of at least 1 m² per meter of length of the tunnel. In particular, the lighting body has a surface of at least 1.5 m² per meter of length of the tunnel. More in particular, the lighting body has a surface of at least 2 m² per meter of length of the tunnel, even more in particular, the lighting body has a surface of at least 2.5 m² per meter of length of the tunnel. Preferably, the lighting body has the shape of a continuous stripe or of continuous stripe portions arranged along the wall of the tunnel, in particular arranged at a distance parallel to the ground level, having a predetermined width and arranged at a predetermined distance from the ground. In particular, the stripe is located between a lower height on the wall and a upper height on the wall. Advantageously, the lower height is at a distance from the ground set between 0 m and 0.8 m. Preferably, the width of the stripe is at least 0.5 m, more preferably, the width is at least 1 m, more preferably the width is at least 1.5 m, more preferably the width is at least 2 m, more preferably the width is at least 2.5 m, determined from the lower height of the stripe.

In alternative, or in addition, the passive lighting element is arranged along a surface of a containing structure of the road environment, in particular along the surface of a guard-rail or of a parapet, or along the surface of a New Jersey- type barrier.

The passive lighting element may be arranged at fixed structures that limit the road environment, such as facades of buildings along the road environment, as well as sound absorbing panels.

In alternative, or in addition, the passive lighting element is a stripe arranged along a portion of a pavement, in particular of a pavement in a tunnel, in particular the portion of the pavement upon which the stripe is arranged is selected among the baseboard and an edge of the pavement, or a combination thereof.

The lighted environment that is provided with passive lighting elements, according to the invention, may also be an environment confined within walls, such as an underground station, an underground car park, a shop, for example a mall, a gym, a sports hall, a swimming pool, and the like.

Another advantage of some photoluminescent material and of passive lighting elements comprising a photoluminescent pigment is that they can emit a secondary light flux that is strong enough to highlight, in particular, of side road stripes, containment structures of road environments, even if they have been lighted for a short time, i.e. a few minutes, by active lighting bodies such as the projectors of a car. Therefore, the method advantageously comprises, a step of measuring an effective illuminance at least one location of the environment, and a step of adjusting the supplied electric power such that the measured illuminance has a value close to said predetermined illuminance value.

Furthermore, the photoluminescence provides a lighting also in road environments, and other environments that do not receive any permanent natural or artificial lighting, for instance roads and tunnels that are not provided with a lighting installation and that are only lighted by the projectors of vehicles travelling along them.

In particular, the photoluminescent pigment is adapted to emit a photoluminescent light flux comprising a light in a visible wavelength spectrum portion that substantially corresponds to a yellow-green light. More in detail, this photoluminescent light flux comprises a light in a wavelength substantially ranging from 500 nm to 590 nm, more in particular, from 510 nm to 580 nm, even more in particular, from 520 nm to 570 nm. This way, the eye of a subject who comes from a floodlit outer environment adapts more easily and quickly to the lighting conditions of the lighted environment, since the light of the photoluminescent light flux is in the human eye maximum sensitivity region. Therefore, even in the case of a photoluminescent flux remarkably weaker than the primary flux, the eyes quickly adapt to the change from daylight to the lighting conditions that are present in the environment. In other words, the yellow-green light assists and accelerates the passage from the photopic vision, which is typical of a luminance higher than 3 cd/m², to the scotopic vision, which is typical of a luminance higher than 0.001 cd/m². Typically, the adaptation time is reduced by 1/3. For instance, in certain conditions the adaptation time of a normal eye, changes 3 seconds to 2 seconds. This technical effect is particularly advantageous in the case of road tunnels, since it makes it possible to shorten the so-called reinforced-lighting portion at the entry by about one third of the normal lengths, under a same eye adaptation, for instance, in a motorway tunnel, from 240-250 m to 160-170 m, thus remarkably reducing the construction costs and/or the energy consumptions of the lighting installation. Most of the photoluminescent pigments, as they are produced by a chemical synthesis process, are characterized by a yellow-green luminescence.

However, the colour of the photoluminescent light flux emitted by the photoluminescent pigment may be a colour different from yellow-green, for instance the colour of the photoluminescent light flux can be one of the colours allowed for traffic signs, i.e. white, blue, red and other.

In particular the photoluminescent pigment comprises Europium (Eu) and/or Dysprosium (Dy), for example it comprises isotopes of Eu and/or Dy. For example, the photoluminescent pigment comprises a material of formula Al_xSr_yCa(i.y)O_z:Eu,Dy, where x,y,z are integer numbers, and/or it comprises a Europium and/or Dysprosium-doped alkaline-earth metal aluminate, in particular a material of formula SrAl20₄:Eu,Dy or

In an exemplary embodiment, the photoluminescent pigment comprises a formulation containing, in predetermined proportions:

Dysprosium trioxide Dy₂03i

Strontium carbonate Sr2C0₃;

Trialumintum oxide AI2O3;

Europium trioxide EU2O3;

- Boric acid H3BO4.

In particular, the photoluminescence of some of these substances is not associated with the emission of potentially health detrimental radiations, in other words these substances are not significantly radioactive, unlike other luminescent material and phenomena. For this reason, these substances can be normally used in places where people or animals may be present or pass through.

In an exemplary embodiment, the step of installation of passive lighting elements comprises a step of painting a wall facing the environment with a paint comprising the photoluminescent pigment. Advantageously, the paint is obtained by a process that comprises mixing the photoluminescent pigment with a resin, typically a siloxane resin.

In this case, a step can be provided of regenerating a surface layer of an existing passive lighting element having an opaque surface exposed to the environment, this step of regenerating comprising a step of application of a coat of paint, or of transparent resin of the paint, on the opaque surface of the passive lighting element, in order to remove opaque deposits and to restore the optical performance of the passive lighting element.

The method may comprise a step of prearranging a removable element, i.e. one that can be installed and then removed, which has a surface comprising the photoluminescent pigment, in particular a step of prearranging a panel, a plate or a tile, wherein the step of installing passive lighting elements comprises a step of arranging the removable elements in the environment.

The active lighting bodies of a lighting installation of a road or motorway tunnel are advantageously provided with shield members arranged for shielding the users of the tunnel who travel in the travelling direction of the tunnel, from the primary light flux, such that the primary light flux produces the required illuminance without dazzling the users. This allows an optimal exploitation of the photoluminescent light flux produced by the passive lighting element or elements, since the user experiences a less pronounced pupil shrinking due to the light flux coming from the active lighting bodies.

The above mentioned objects are also reached by a passive lighting element for a lighting installation of an environment intended for the stay and/or for the passage of people and/or vehicles, where the passive lighting element comprises a photoluminescent pigment. In particular, the passive lighting element is made and arranged in this environment according to the steps of the method described above, In particular, the photoluminescent pigment comprises Europium (Eu) and/or Dysprosium (Dy), for instance it comprises isotopes of Eu and/or Dy. In particular, the photoluminescent pigment comprises a material of formula

where x,y,z are integer numbers, or it comprises a metal alkaline earth aluminate, for example a material of formula SrAI₂0₄:Eu,Dy or SrAl₂0 :Eu,Dy,B.

The above mentioned objects are also reached by a lighting apparatus for lighting, with a predetermined illuminance value, an environment intended for the stay and/or for the passage of people and vehicles, in particular an environment confined within walls such as a road or pedestrian tunnel, an underground station or an underground car park, the apparatus comprising: at least one electrically suppliable active lighting body configured to generate a primary light flux;

- at least one passive lighting element comprising a photoluminescent pigment adapted for emitting a predetermined photoluminescent light flux when exposed to the primary light flux;

wherein the at least one active lighting body and the at least one passive lighting element are arranged in use in the environment according to a mutual position such that the at least one passive lighting element receives the primary light flux, wherein the at least one active lighting body and the at least one passive lighting element are selected in such a way that, by supplying the at least one active lighting body with a predetermined electric power, the primary light flux and the photoluminescent light flux produce together the predetermined illuminance value.

It falls within the field of the invention also the use of a photoluminescent pigment to make a passive lighting element for an environment lighted by a lighting installation, the installation comprising at least one electrically suppliable active lighting body, in particular the photoluminescent pigment comprising Europium and/or Dysprosium, more in particular, the photoluminescent pigment comprising an Europium and/or Dysprosium-doped alkaline-earth metal aluminate, in particular a material of formula SrAkO-f.Eu.Dy or SrAbCV.Eu.Dy.B.

Brief description of the drawings

The invention will be now shown with the description of exemplary embodiments of the method and of the apparatus, as well as of the passive lighting element according to the invention, exemplifying but not limitative, with reference to the attached drawings, in which like reference characters designate the same or similar parts, throughout the figures of which:

— Fig. 1 diagrammatically shows an environment provided with a lighting apparatus comprising active electrically suppliable lighting bodies, and comprising passive lighting elements photoluminescent as well;

— Fig. 2 is a diagram that shows the post-luminescence intensity of some photoluminescent material after an exposition to an excitation illuminance of 1000 lux for 10';

— Figs. 3-5 show a road/pedestrian tunnel equipped with a lighting apparatus comprising active lighting bodies and passive lighting elements, in particular:

— Fig. 3 is a perspective view of an end portion of the tunnel;

— Fig. 4 is a cross sectional view taken along a plane parallel to the road floor;

— Fig, 5 is a longitudinal sectional view; — Figs. 6-8 show a road/pedestrian tunnel equipped with active lighting bodies and with passive lighting elements according to another exemplary embodiment, having an increased lighting capacity, in particular

— Fig. 6 is a perspective view of an end of the tunnel;

5 — Fig. 7 is a cross sectional view taken along a plane parallel to the road floor;

— Fig. 8 is a longitudinal sectional view of the tunnel;

— Fig. 9 is a perspective view of a road environment equipped with active lighting bodies and with passive side lighting elements, according to a further l o exemplary embodiment of the invention;

— Figs. 10 and 1 1 are longitudinal sectional views of a tunnel as in Figs. 3-9, comprising a lighting reinforcement installation without, and in the presence of, photoluminescent passive lighting elements, respectively;

— Fig. 12 diagrammatically shows an environment as in Fig. 1 , which also 15 comprises a adjustment means for adjusting the power supplied to the active lighting bodies according to an illuminance that is obtained in the environment;

— Fig. 13 diagrammatically shows the layers of a passive lighting element applied by painting;

— Fig. 14 shows the element of Fig. 13 after a step of regeneration;

0 — Figs. 15, 16 and 17 show a portion of a motorway tunnel used for carrying out lighting performance tests of the passive lighting elements according to the invention, in a cross sectional view facing the road surface, in a longitudinal sectional view taken along the middle plane, and in a cross sectional view facing the vault of the tunnel;

5 — Fig. 18 is a diagram that shows the decay of the photoluminescent luminance delivered by a passive lighting element according to the invention, after switching off the active lighting bodies in the tunnel of Figs. 15-17.

Description of preferred exemplary embodiments

Fig. 1 shows an environment 12, which can be an environment defined by0 building structures such as walls 10, a ground 31 and a ceiling or vault 30, intended for the stay and/or for the passage of people and/or vehicles, such as a road or pedestrian tunnel, an underground station, an underground car park, a shop, a sports place and the like, and provided with an electric lighting installation. The lighting installation comprises at list one lightering active body 19, where "active" means that they are connected to an electric supply device 26. Active lighting body 19 is configured and arranged for generating a primary light flux 19' in environment 12. At least one passive lighting element 13 is arranged within environment 12, for example at a wall 10, which comprises a photoluminescent pigment laying on its own surface.

In this description, photoluminescent pigment means a material that is adapted to receive the primary light flux, for example primary light flux 19' produced by lighting bodies 19 of the electric lighting installation of environment 12, and adapted to emit a photoluminescent light flux 13' in response to primary light flux 19', a delay time after primary light flux 9' is received, and during a predetermined time.

More in detail, a pigment is considered to be photoluminescent if, after an excitation by exposition to a predetermined illuminance level during a determined time, for example a few minutes, it remains luminous, i.e. it continues to emit a secondary or photoluminescent light radiation for a certain time, for example for about 30-40 minutes, at a luminance higher than a predetermined value.

For example, according to DIN67510, a photoluminescent pigment is one that remains luminous for more than 30 minutes at a luminance of at least 0.003 cd/m² (candela on square meter), after an excitation by exposition to 1000 lux for 5 minutes,.

The photoluminescent pigment may comprise Europium (Eu) and/or Dysprosium (Dy), and/or respective isotopes. In particular, the photoluminescent pigment may comprise a material of formula AlxSryCad-y_jOziEu.Dy, where x,y,z are integer numbers.

The photoluminescent pigment may also comprise an alkaline-earth metal aluminate, for example a material of formula SrAl₂04:Eu,Dy or SrAl20₄:Eu,Dy,B. For example, the photoluminescent pigment may be a pigment known as HG- 4B or MHG-4C.

A material of this kind has no significant radioactivity, after an exposition to an illuminance excitation of 1000 lux for 10' to 23°C it shows a post- luminescence intensity that changes with time, as indicated by the diagram of Fig. 2. In an exemplary embodiment, a photoluminescent pigment may have a formulation containing, in predetermined proportions, substances such as:

Dysprosium trioxide Dy20₃;

Strontium carbonate Sr2C0₃;

- Trialuminium oxide Al₂0₃;

Europium trioxide EU2O3;

Boric acid H3BO4.

Active lighting bodies 19 may be lighting well-known bodies, preferably LED lighting bodies, but also halogen or metal halogenide lighting bodies, high pressure sodium lighting bodies, incandescent lighting bodies. In order to activate the photoluminescent pigment, active lighting bodies 19 are preferably configured for emitting a light of a wavelength shorter than 480 nm, more in particular, shorter than 450 nm, even more in particular, shorter than 430 nm, which corresponds to the blue-violet-UV or to the violet-UV wavelength spectrum portion.

Still with reference to Fig. 1 , when active lighting body 19 is supplied with an electric power predetermined by electric supply device 26, primary light flux 19' produced by active lighting body 19 is summed to photoluminescent light flux 13' produced by auxiliary lighting bodies 13, creating an illuminance of a determined value in environment 12.

The illuminance value may be a predetermined illuminance value for environment 12, i.e. a design illuminance value for a lighting installation of environment 12, for example a design value as prescribed by a rule.

The consequence of using passive lighting elements 13 is a decrease of the radiating power required by active lighting bodies 19 to obtain the predetermined illuminance value in environment 2, with respect to the case in which passive lighting elements 13 are not present. This reduces firstly the overall electric power to be supplied to active lighting bodies 19. For instance, in an environment 12 provided with an electric lighting installation, this can be preferably carried out by adjusting the supplied electric power to active lighting bodies 19. As an alternative, only some of the of active lighting bodies 19 may be powered, or active lighting bodies 19 may be replaced with lower lighting powering bodies.

In case of an environment 12 for which a new lighting installation has to be built, active lighting bodies 19 can be designed, i.e. their nominal power can be selected, as well as their number and their position, and passive lighting elements 13 can be selected and dimensioned, in such a way that the prescribed or required design illuminance of environment 12 is obtained by summing the effects of primary light flux 19' and of photoluminescent light flux 13'. Passive lighting elements 13 are arranged at positions of environment 12 that allow them to receive primary light flux 19'.

With reference to Figs. 3-5, a passive lighting element 13 is described that is arranged on a surface 10 in an environment, in this case a road environment that can be at least in part within a tunnel 1 1 . In an exemplary embodiment, as shown, tunnel 1 has a lighting installation that comprises a plurality of electrically suppliable active lighting bodies 19, such as lighting bodies 19, which are arranged, for example, along the middle line of vault 20 of tunnel 11. Active lighting bodies 19 are configured for emitting a primary light flux 19'.

In this exemplary embodiment, passive lighting element 13 is made or arranged on the surface of a side wall 10 of tunnel 1 1. The passive lighting element may have the shape of a stripe 13 arranged along wall 10. In the case shown, stripe 13 is parallel to ground 9, and has a width H. For a given power of each lighting body 19 and for a given width H of photoluminescent stripe 13, tunnel 1 1 may be provided with a predetermined illuminance by arranging lighting bodies 19 at a predetermined mutual distance D.

In order to obtain an appreciable contribution to the illuminance in the tunnel, width H is at least 0.5 metres, advantageously it is at least 1 m, preferably it is at least 1.5 m, more preferably it is at least 2 m, even more preferably the width it is at least 2.5 m, measured from the lower height of the stripe. This way, passive lighting element 13 has a surface of at least 0.5 m², 1 m², 1.5 m², 2 m² 2.5 m² per meter of length of tunnel 1 1 , respectively, by which a contribution to the overall illuminance of tunnel 11 is obtained that is substantially proportional to the overall surface area A of the passive lighting element or elements 13. In an exemplary embodiment, as shown, if L is the length of tunnel 11 or of the portion of road along which stripe 13 is applied, overall surface area A is equal to LxH, and the photoluminescent light flux that is returned by stripe 13 for a predetermined primary flux produced by lighting bodies 19 is substantially proportional to the surface area to and to primary light flux 19' that stripe 13 receives from lighting bodies 19 of the lighting installation.

For this reason, as diagrammatically shown in Figs. 6-8, the contribution of photoluminescent light flux 13' provided by stripe 13 can be increased, and the contribution of light flux 19' emitted by lighting bodies 19 can be decreased accordingly by increasing the width of stripe 13, maintaining a same illuminance in tunnel 1 1 . More in detail, with a width H' of stripe 13 larger than width H of Fig. 3, the active lighting bodies can be arranged at a mutual distance D' higher than mutual distance D of Fig. 3, in order to obtain the same illuminance in tunnel 11. In another exemplary embodiment, not shown, with an increased width H' of stripe 13, lower-lighting powering bodies 19 can be used, or the power actually supplied to active lighting bodies 1 of a predetermined nominal power can be in any case reduced, for example, by arranging passive lighting bodies 13 in a tunnel provided with a lighting installation that comprises existing electric lighting bodies.

Therefore, passive lighting elements 19 reduce the lighting power, with an energy saving depending upon width Η,Η' of stripe 13 or, more in general, upon the overall surface area Α,Α' of passive lighting element or elements 13 arranged in tunnel 1 1. Furthermore, when building a new lighting installation, passive lighting elements 3 allow reducing the number of active lighting bodies 19 or using lower power active lighting bodies 19, which contains the cost of the electric lighting installation.

Obviously, within practical limits of application of stripe 13, an optimal value of width Η,Η' of stripe 13 can be assessed by comparing the cost of stripe 13, for example the cost for purchasing and applying the photoluminescent material, with the decrease of construction and operation costs of the electric lighting installation, in terms of amortization.

These remarks about energy saving and/or cost reduction also apply to a different environment 12 confined within walls in which a permanent or only a night electric lighting installation is or must be provided, such as an underground or any closed car park, not shown.

Still with reference to Figs. 3-8, stripe 13 may be arranged at a distance h from ground 9 set between 0 m and 0.8 m. For instance, stripe 13 may be arranged on the whole lower portion of wall 10, i.e. at a substantially zero distance from ground 9.

The overall surface of passive lighting element 31 , which is advantageously the same as indicated above, may even have a shape different from what is shown in Figs. 3-8. For example, according to further exemplary embodiments, not shown, passive lighting elements may be provided in the form of discontinue side stripes i.e. in the form of continuous stripe portions, and/or passive lighting bodies in the form of a plurality of stripes arranged at different heights from ground 9.

Advantageously, a passive lighting element is arranged on the wall 10' of tunnel 11 opposite to wall 10, that is similar to the element arranged or formed on wall 10, such that the overall surface of both passive lighting elements is double than the surface indicated above, therefore a substantially double energy saving is obtained, and in the case of a new installation, the capital cost decreases remarkably.

Active lighting bodies 19 of the lighting installation of tunnel 11 may be provided with shield members, not shown, arranged for shielding the users of tunnel 11 who proceed in the prescribed advancement direction, from primary light flux 19' produced by active lighting bodies 19, in order to avoid dazzling the users while providing the required illuminance. This is particularly advantageous in a motorway tunnel or in a one-way tunnel. For instance, the shield members may be screens arranged in a rear portion of active lighting bodies 19, with respect to the advancement direction, so that active lighting bodies 19 can bee seen by the users only when they are just below each active lighting body 19. The same effect can be obtained by using lighting bodies that are configured for projecting light mainly according to a predetermined direction and are oriented, to project light forward, according to the advancement direction.

The passive lighting elements or body 13 can also receive, beside the light flux of lighting bodies 9, a further variable light flux produced by the projectors of the advancing vehicles, not shown. Without the light flux of lighting bodies 19, in a steady condition the light flux returned by stripe 13 is substantially proportional to the contribution of the projectors of the advancing vehicles.

If lighting bodies 19 of the lighting installation are switched off, photoluminescent light flux 13' returned by stripe 13 decreases with time after switching off lighting bodies 19. In the lighting conditions normally provided in a tunnel, photoluminescent light flux 13' returned by stripe 13 will remain strong enough to highlight wall 10,10' of tunnel 1 1 for a certain time, which is normally 30 - 40 minutes. Therefore, passive lighting elements 13 can collaborate with or even replace the continuous power sources provided to face a temporary black-out condition involving active lighting bodies 19.

In another exemplary embodiment, as shown of Fig. 9, passive lighting element 13 may be arranged, inside or outside tunnel 1 1 , on a side structure of road environment 12, such as a surface of a sound-absorbing panel 17, a guard-rail 18 or a parapet, or of any fixed structure that limits the road environment, for example facades of buildings facing the road environment, not shown.

The passive lighting element may be made also on a pavement 14, for example an edge 16 or a baseboard 15 of pavement 14 (Figs. 3,6). Passive lighting element 13 of edge 16 of pavement 14 can also assist possible pedestrians walking along tunnel 1 , if the permanent electric lighting bodies 19 breaks down.

With reference to Fig. 12, environment 12 of Fig. 1 may be advantageously provided with a means for adjusting the power supplied to the active lighting body or bodies 19, comprising a sensor of illuminance 21 associated with a transducer 22 configured for providing an electric signal 23 of illuminance, typically a 4-20 mA electric signal, and a regulator 24 configured for receiving electric signal 23 and for generating an adjustment signal for adjusting the power supplied by electric supply device 26 to lighting body or bodies 19. This device has a specific advantage in a tunnel 1 1 , in particular in a tunnel where the powerful lighting bodies of the reinforced-lighting portion give an important contribution to lighting, in order to take into account the inexpensive contribution provided by the projectors of the vehicles travelling during intense traffic hours.

With reference to Figs. 10 and 11 , still in the case of road or motorway tunnel 1 1 , an electric lighting installation is shown that comprises active lighting bodies 19, and has a reinforced-lighting portion 33 at an entry portion of tunnel 11 . In reinforced-lighting portion 33 a higher lighting power is installed than in the inner portion of the tunnel, in order to help the car driver's eyes to get accustomed in the transition from the outside daylight to the artificial light within tunnel 1 1 , when entering into the tunnel. For instance, in reinforced-lighting portion 33 higher power active lighting bodies 9 of and/or more closely stepped lighting bodies may be installed. In the latter case, the lighting bodies in the reinforced-lighting portion are arranged at mutual distances DV, D2', D₃' (Figs. 10,11) and DV (Fig. 10), which preferably increase away from the entry portion of tunnel 11 , which are shorter than the distance D' between active lighting bodies 19 that are arranged in the inner portion of tunnel 1. Fig. 10 shows a tunnel conventionally equipped with a continuous white stripe 25, where the reinforced-lighting portion has a length R, which in the case of a common motorway is about 240-250 m, for example. Instead, Fig. 11 shows a tunnel 11 equipped with a passive lighting element 13, according to the invention, that has the form of a photoluminescent stripe 13 arranged along at least one wall 10 of the tunnel, in which the pigment of stripe 13 is configured to emit a light with a wavelength spectrum that mainly lies in the spectrum portion corresponding to a yellow-green light, typically between 500 and 590 nanometres, or between 510 and 580 nanometres, or between 520 and 570 nanometres. The human eye get accustomed more quickly to a light comprising the contribution of such a light flux, which allows a reinforced-lighting portion of a length R' shorter than normal length R. This way, once again, a saving of the lighting electric power is possible as well as a reduction of the cost of a possible new installation.

In an exemplary embodiment, not shown, a passive lighting element, for example in the form of a continuous or discontinuous stripe containing the photoluminescent pigment, can be arranged along a guard-rail, thus obtaining firstly a reduction of the road lighting installation, as well as an effective signalling of the carriageway and/or lane side limits. In the case of tunnel 1 1 of Figs. 3-8 and 10-11, the guard-rail can be a protection structure for possible pedestrians walking on pavement 14.

With reference to Fig. 13, the stripe, or in any case passive lighting body 13 can be made by painting, i.e. by applying one or preferably two layers 35,36 of a paint that contains the photoluminescent pigment and, for example, a transparent synthetic resin such as a siloxane resin. The painting can be carried out by any known painting technique, for example a technique selected among a spray painting technique, a brush painting technique, a roller painting technique, a knife painting technique. The paint normally comprises further components, beside the pigment, and may be formulated conventionally, i.e. it may comprise components that are present in common general purpose paints, in particular, for example, they may comprise synthetic resins.

5 Advantageously, the method for making passive lighting bodies 13, in case of painting, may comprise a step of preparing a surface 27 to be painted, before the step of painting. This step of preparation may serve to help the adhesion and/or to improve the duration of a layer 35 or of a stripe 13 containing the photoluminescent pigment on surface 27, in case of a surface 27

10 irregular or particularly rough or smooth. In particular, the step of preparation, as briefly described hereinafter, is useful for applying stripe 13 comprising photoluminescent pigment on side walls 10, 0' of tunnel 11 (Figs. 3-8).

The step of preparation may comprise a preliminary sandblast step of surface 27, in particular a steam sandblasting, or any other known technique of i5 preparing a wall surface to be painted. This makes it possible to clean surface 27 of wall 10,10^* and/or to obtain a suitable surface roughness or porosity, in order to cause to enhance adhesion and resistance of a painted passive lighting element 13, i.e. in order to provide a surface roughness suitable for steadily receiving the paint comprising the photoluminescent pigment.

20 In alternative, or after the sandblast, the step of preparation may provide a step of application of a primer layer comprising a clear primer layer 34, in particular of a covering primer 34, preferably a substantially white primer 34. In particular, the step of application of primer 34 may have a covering function, in the case of a dark surface 27, as usually is a wall of a tunnel. This makes it

25 possible to contain the thickness of layers 35,36 of stripe 13 of photoluminescent material, then allows a better performance and therefore a saving of photoluminescent pigment.

Preferably, the step of applying primer 34 comprises a step of drying the primer that may be carried out, for example, by warm air or gas, i.e. a step of

3o quick evaporation of the primer, by heating and maintaining the layer of primer at a temperature for a time which according to the nature of the primer itself.

Passive lighting element 13 that exposes the photoluminescent pigment may also be mounted by a serigraph printing technique.

With reference to Fig. 13, the method may also comprise a step of regenerating an existing passive lighting element 13 that comprises at least one layer 35, or preferably at least two previous layers 35,36, in which the surface layer 35 or 36 is opaque by exposition to the environment. The step of regenerating comprises a step of applying a coat of paint 38, or of a coat 38 of the same transparent resin of to the paint, directly upon opaque surface 37 of passive lighting element 13, in order to remove the opacifying agent, for example by dissolving it, and to restore the optical performance of previous layers 35,36 of paint. The method makes it possible not to remove any material before applying the new coat of paint 38. This way, the restored passive lighting element provides a photoluminescent light flux that is the sum of a first contribution, substantially equal to the photoluminescent light flux provided by previous layers 35,36 as originally applied, and of a contribution provided by the new layer or coat of paint 38 comprising the photoluminescent pigment. In other words, the step of regenerating, which may be carried out, for example, some years after the first application, forms a passive lighting element 13 that is more powerful than it was when initially applied.

In an exemplary embodiment, passive lighting element 13 may also comprise plane elements which can be fixed on the details to be highlighted, for example boards or tiles or panels providing a surface that comprises the photoluminescent pigment, which can be fixed by a known technique on a surface of environment 11 ,12. Accordingly, the method may provide the preparation of these flat elements, and the subsequent application of these plane elements on the surface on which passive lighting element 13 is desired. For instance, stripe 13 of Figs, 3-11 may be made by applying a plurality of such boards or tiles or panels on wall 10,10' of tunnel 11 , or at baseboard 15 or edge 16 of pavement 14, or on sound-absorbing panel 17 (Fig. 9).

EXAMPLES

Three tests have been carried out for assessing the lighting performances of a passive lighting element obtained by applying a layer of paint comprising a photoluminscent pigment on a wall of a motorway tunnel. Tunnel 1 1 is diagrammatically shown in Fig. 15, in a section facing a carriageway 9, in Fig. 16, in a longitudinal cross section, and in Fig. 17 in a view facing vault 20 of tunnel 11. Environment of carrying out a test

The tests have been carried out in the abandoned Camillini Tunnel, exploited by the company Autostrade per I'ltalia S.p.A., along Italian motorway A1 (Milan-Naples), more precisely between Sasso Marconi and Barberino del 5 Mugello, by specialists of the Genoa University, at the presence of the technicians of the company Autostrade per I'ltalia S.p.A.

Active lighting bodies in the environment

The tunnel has active lighting bodies 19 arranged in one row at a height of 5.7 metres above road surface 9, shift 1.2 metres on the left side with respect to ! O the middle vertical plane X-X of carriageway 9.

100 W lighting bodies 19 are arranged at a distance D of 10 metres, and are configured to receive an electric supply of 50 Hz, 230 V. During the test, the regulation system of active lighting bodies 19 was disabled.

Passive lighting elements and reference

15 A first rectangular portion 41 of left wall 0 of the tunnel, which had a 10 m long longer edge B arranged parallel to the ground, at a distance h of 0.8 metres from the ground, and a 2 m log shorter edge H, was painted with a white paint and served as a reference in the test.

A second portion 42 of same wall 10, of the same shape and the same 20 size B,H, at a distance 2D from portion 41 along tunnel 1 1 , was painted with a paint containing a photoluminescent pigment, so a passive lighting element was obtained according to the invention.

The tunnel had also normal horizontal road markings, comprising white longitudinal lines, like the centre line and the side lines of carriageway 9.

25 Test procedures, measurements and reference regulations

During the tests, average luminance measurements were carried out on tunnel wall portions 41 ,42 and on road surface portions 43,44 (calculation areas), as described hereinafter.

The measurement instruments were arranged to measure the luminance 30 as it was perceived by a standing observer located at a position 45 in the middle line of a lane, at a distance F of 60 metres upstream of the area of calculus, with respect to to the travelling direction 11. This procedure is in accordance with pertaining regulations, UN1 11095:20 . Instruments used

To carry out the measurements, the instruments comprised:

a model 98-2 luminance measuring device of the Techno-Team brand, measuring range 0.1-10Ό00 cd/m²;

a model T-10 luxmeter of the Minolta brand, measuring range

0.01-299900 lux, class of precision ±2%, ±1 digit of value measured,

both complying with the above mentioned rules.

Environmental conditions during the test

The tests were carried out at a temperature of about 3^eC and out of daylight.

First test

After switching active lighting bodies 19 on, luminance measurements were carried out on first wall portion 41 (reference) and on second wall portion 42 (painting according to the invention).

On first wall portion 41 a 2.348 cd/m² luminance was measured, whereas on second wall portion 42 a 3.257 cd/m² luminance was measured. This corresponds to a luminance increase of 38.71 % at painting 42, obtained by a passive lighting element according to the invention, with respect to a common white painting.

Second test

After switching active lighting bodies 19 on, luminance measurements were carried out on portions 43,44 carriageway 9 facing first wall portion 41 (reference) and second wall portion 42 (painting according to the invention).

On carriageway portion 43 facing first wall portion 41 a 1.498 cd/m² luminance was measured, whereas on carriageway portion 44 facing second wall portion 42 a 1.64 cd/m² luminance was measured. This corresponds to a luminance increase of 9.48%, obtained by a passive lighting element 13 according to the invention, with respect to a common white painting.

Contribution to luminance - Reduction of lighting energy consumption

On the basis of the tests, it is possible to estimate a minimum value of the contribution to total luminance allowed by passive lighting elements according to the invention arranged on the wall of a tunnel, in a reference condition defined by width H of painted portion 42, i.e. 2.0 m, corresponding to 2.0 m² per meter of length of the tunnel. If the second test is used as a reference, the above increase value (9.48%) is to be considered as a minimum value of the contribution to total luminance, since:

it relates to a single painted portion 42, which has a short length B, in other 5 words, no account is taken of the contribution of adjacent portions which may form a stripe 13, as shown in Fig. 3 and 6.

Moreover, remarkable improvements of the contribution can be obtained: by increasing width H of stripe 13 with respect to the reference value used in the test (for example, increasing width H from 2,0 metres to 2.5 metres);

lo by arranging a similar passive lighting element 13 also on right wall 10' of the tunnel, which approximately doubles the contribution with a same width H.

In order to assess the advantages of passive lighting elements 13 according to the invention with respect to the common white painting, it ha sto be taken into consideration that the lighting performances of a white painting i s decrease with time, remarkably quicker than the lighting performances of the passive lighting elements. This behaviour is particularly prominent with respect to the lighting performances of a stripe made by a paint that contains a photoluminescent pigment. This depends upon a higher disposition of conventional paints to receive opaque deposits of dust, exhaust gas vehicles0 and so on.

In view of the above, a contribution of luminance of 23.7% can be assumed for a tunnel that has both walls painted with a 5 metres width continuous stripe.

These values of contribution to luminance, which are given as a result of5 lighting measurements or as a projection of these results to an ideal installation of passive lighting elements according to the invention, can be considered as a first approximation of the saving of energy, at a same luminance, or at a same lighting condition, that can be obtained by installing passive lighting elements in an environment such as a motorway tunnel.

0 Third test

Active lighting bodies 19 were kept on and then were switched off. Luminance measurements were carried out immediately on portion 44 of carriageway 9 facing second portion 42 of painted wall, during 30 minutes and at a frequency of 30 seconds. In particular, immediately after switching off active lighting bodies 19, the luminance on the second wall portion was 0.0897 cd/m2, 30 minutes later the residue luminance was 0.03263 cd/m2, which is 36.4% of the value measured just after immediately switching the active lighting bodies off.

In Fig. 18 provides a diagram of decay of the luminance measured on portion 44 of carriageway 9 facing the second painted wall portion, between the switch-off (t=0) and 30 minutes (1800 s) after switching off active lighting bodies 19.

The foregoing description of some exemplary embodiments will so fully reveal the invention according to the conceptual point of view, such that others, by using the prior art, will be able to modify and/or adapt for various applications such exemplary embodiments without further research and without parting from the invention, and, accordingly, it is understood that such adaptations and modifications will have to be considered as equivalent to the exemplary embodiments. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is meant that the expressions or the terminology used herein is for the purpose of description and not of limitation.

Claims

A method for lighting with a predetermined illuminance value an environment (11 ,12) intended for the stay and/or for the passage of people and/or vehicles, said environment having at least one electrically suppliable active lighting body (19), said active lighting body (19) generating a primary light flux (19'),

said method comprising the steps of:

selecting at least one passive lighting element (13) comprising a photoluminescent pigment, said at least one passive lighting element (13) configured for emitting a photoluminescent light flux (13') responsive to an excitation by said primary light flux (19');

installing said at least one passive lighting element (13) in said environment (11 ,12) at a position arranged to receive said primary light flux (19');

supplying at least one part of said at least one active lighting body (19) with an electric power such that said at least one active lighting body (19) generates said primary light flux (19') that summed to said photoluminescent light flux (13') produces said predetermined illuminance value.

A method for lighting with a predetermined illuminance value an environment (11 ,12) intended for the stay and/or for the passage of people and/or vehicles,

said method comprising the steps of:

selecting at least one electrically suppliable active lighting body (19), said active lighting body (19) configured to generate a primary light flux (19');

wherein said at least one active lighting body (19) and said at least one passive lighting element (13) are selected in such a way that, by supplying said at least one active lighting body (19) with a predetermined electric power, said primary light flux (19') and said photoluminescent light flux (13') produce together said predetermined illuminance value;

installing, in said environment (11 ,12), said at least one active lighting body (19) and of said at least one passive lighting element (13), 5 said at least one active lighting body (19) and said at least one passive lighting element (13) arranged at a mutual position such that said at least one passive lighting element (13) receives said primary light flux (19'); supplying said at least one active lighting body ( 9) with said electric power.

l o

3. A method according to claim 1 or 2, wherein said environment is a road, motorway or pedestrian tunnel (1 1 ).

4. A method according to claim 3, wherein said passive lighting element (13) is continuously or discontinuously arranged along a wall of said tunnel (1 1 ), said passive lighting element (13) having a surface of at least 0.5 m² is per meter of length of said tunnel, in particular said lighting body having a surface of at least 1 m² per meter of length of said tunnel, more in particular, said lighting body having a surface of at least 1.5 m² per meter of length of said tunnel, even more in particular, said lighting body having a surface of at least 2 m² per meter of length of said tunnel, even more in0 particular, said lighting body having a surface of at least 2.5 m² per meter of length of said tunnel (1 ).

5. A method according to claim 4, wherein said lighting body has the shape of a continuous or discontinuous stripe (13) arranged along the wall (10, 10') of said tunnel ( ), in particular said stripe (13) is arranged 5 parallel to the ground (9).

6. A method according to claim 1 or 2, wherein said environment is a road or motorway environment (12), and said passive lighting element (13) is arranged along a side structure (17,18) of said road or motorway environment (12), in particular said side structure selected from the group0 consisting of:

a containing structure of said road environment (12), in particular selected between a guard-rail (18) and a New Jersey-type barrier; a sound-absorbing panel (17);

a facade of a building facing said road environment (12); a portion of a pavement (14).

A method according to claim 1 or 2, wherein said environment (12) is selected from the group consisting of:

an underground station;

an underground car park;

a shop;

a sports place, in particular a swimming pool or a sports hall.

A method according to claim 1 or 2, wherein said photoluminescent pigment is adapted to emit said photoluminescent light flux that comprises light in a wavelength substantially ranging from 500 nm to 590 nm, in particular from 510 nm to 580 nm, more in particular, from 520 nm to 570 nm.

A method according to claim 1 or 2, comprising a step of measuring an effective illuminance in at least one point of said environment (12), and a step of adjusting said supplied electric power such that said detected effective illuminance has a value close to said predetermined illuminance value.

A method according to claim 1 or 2, wherein said photoluminescent pigment comprises Europium (Eu) and/or Dysprosium (Dy),

in particular, said photoluminescent pigment comprises a material selected from the group consisting of:

a material of formula AlxSryCao-y ziEu.Dy, wherein x,y,z are integer numbers;

an aluminate of an Europium (Eu) and/or Dysprosium (Dy)-doped alkaline-earth metal, in particular a material of formula SrA^O^Eu.Dy or

A method according to claim 1 or 2, wherein said step of installation of passive lighting elements comprises a step selected from the group consisting of:

a step of painting a wall (10,10', 14,17) facing said environment (11 ,12) with a paint comprising said photoluminescent pigment, in particular wherein said paint comprises a transparent siloxane resin; a step of prearranging a removable element that has a surface comprising said photoluminescent pigment, in particular said element selected among a panel, a plate and a tile, wherein said step of installation of passive lighting elements comprises a step of arranging said removable s element in said environment (11,12).

12. A method according to claim 11 , wherein said mounting step comprises said step of painting, and said method comprises a step of regenerating an existing passive Iighting element (13) comprising at least one layer (35,36) of said paint that has an opaque surface (37) exposed too environment (11 ,12), said step of regenerating comprising a step of application of a coat (38) of paint, or of a coat (38) of said transparent resin of the paint, on said opaque surface (37) of said passive Iighting element (13), in order to remove opaque deposits and to restore the optical performance of said at least one layer (35,36) of said paint.s 13. A method according to claim 1 or 2, wherein said at least one active

Iighting body ( ) comprises LED lighting bodies.

14. A method according to claim 1 or 2, wherein said at least one active Iighting body (19) is configured for emitting a primary light flux (19') comprising a light in a spectrum of visible wavelengths lower than 480 nm,0 more in particular, lower than 450 nm, even more in particular, lower than

430 nm,

15. A method according to claim 3, wherein said at least one active Iighting body (19) has shield members arranged for shielding a user of said tunnel ( 1) who proceeds in a predetermined travelling direction within said5 tunnel (11) from said primary light flux, so that said primary light flux produces said illuminance without dazzling said user.

16. A passive lighting element for a iighting installation for an environment ( 1 ,12) intended for the stay and/or for the passage of people and/or vehicles characterised in that it comprises a photoluminescent pigment.

17. A Iighting apparatus for lighting with a predetermined illuminance value an environment (11,12) intended for the stay and/or for the passage of people and vehicles, in particular an environment (11 ,12) confined within walls (10) such as a road tunnel (11) or a pedestrian tunnel, an underground station or an underground car park, said apparatus comprising:

at least one electrically suppliable active lighting body (19) configured to generate a primary light flux (19');

at least one passive lighting element (13) comprising a photoluminescent pigment adapted for emitting a predetermined photoluminescent light flux (13') when exposed to said primary light flux (19');

wherein said at least one active lighting body (19), and said at least one passive lighting element (13) are arranged in use in said environment (1 ,12) according to a mutual position such that said at least one passive lighting element (13) receives said primary light flux (19'),

wherein said at least one active lighting body (19), and said at least one passive lighting element (13) are selected in such a way that by supplying said at least one active lighting body (19) with a predetermined electric power, said primary light flux (19') and said photoluminescent light flux (13') produce together said predetermined illuminance value.

The use of a photoluminescent pigment to make a passive lighting element (13) for an environment (11 ,12) lighted by a lighting installation, said installation comprising at least one electrically suppliable active lighting body ( 9), in particular said photoluminescent pigment comprising Europium (Eu) and/or Dysprosium (Dy), more in particular, the photoluminescent pigment comprising a aluminate of an Europium (Eu) and/or Dysprosium (Dy)-doped alkaline-earth metal, in particular a material of formula SrAlzCV.Eu.Dy or SrAI₂04:Eu,Dy,B.