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(11) | EP 1 174 658 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Light carrier system for natural light |
| (57) A light carrier system for natural light provided with a sun light sensor (11), equipped
with a Fresnel lens (12) consisting of a film and with linear concentration located
outside the building housing the room to be lit, a transport duct (13) and a diffuser
(14), where inside the unit composed of the transport duct (13) and the diffuser (14),
an aluminium reflector curves from the transport duct to the base of the diffuser
(14), touching the lower surface composed of an OLF (Optical Lighting Film) resting
on a sheet of transparent polycarbonate representing the emission surface. The sun
light sensor (11) is capable of following the course of the sun, actively, following
the height on the horizon during the day to optimally take advantage of its capacities
to receive light. |
[0002] It is known that there are many benefits in the use of natural light for illumination inside closed buildings, among which are better chromatic yield of the illuminated objects and reduced use of power for internal illumination.
[0003] However, the use of windows and skylights does not permit optimum efficiency of power, as in any case there is a noteworthy loss of internal heat through them.
[0004] The object of the present invention is, therefore, to provide a light carrier system for natural light which takes full advantage of the external light to illuminate rooms or areas even of large dimensions.
[0005] Another object of the invention is to provide a light carrier system for natural light which allows the course of the sun to be followed to optimise the receiving capacity of the sun's light.
[0006] These and other objects are attained by a light carrier system for natural light, according to claim 1, to which refer for the sake of brevity.
[0007] Further characteristics of the present invention are defined in the claims enclosed with the present patent application.
[0008] Further objects and advantages of the present invention shall become clear from the description below and annexed drawings, showing exemplary and nonlimiting preferred embodiments of the invention, in which:
- figure 1 shows a perspective view of a sun light sensor of natural light, belonging to the light carrier system for natural light of the present invention;
- figure 2 shows a schematic view of the light carrier system for natural light, according to the present invention;
- figure 3 shows a schematic view of the microstructure of a Fresnel lens consisting of a film, employed as a component of the light carrier system for natural light in the previous figures; and
- figure 4 shows a schematic view of the light carrier system for natural light, according to one of its operating modes.
[0009] With specific reference to the figures mentioned, a schematic view of the light carrier system for natural light, according to the present invention, is indicated as a whole with the numeric reference 10.
[0010] The light carrier system for natural light 10 is firstly provided with a sun light sensor 11, equipped with a Fresnel lens 12, consisting of a film and with linear concentration, a transport duct 13 and a diffuser 14.
[0012] The sun light sensor 11 is positioned on the outside of the building in which the light carrier system for natural light 10 is applied, while the diffuser 14 is fitted inside the building, at the end of the transport duct 13.
[0013] The diffuser 14 is a box-like structure having the same width as the transport duct 13 (shown schematically in the annexed figures), while the depth varies according to the measurements of the room in which the light carrier system for natural light 10 is installed.
[0014] Inside the unit composed of the transport duct 13 and the diffuser 14, an aluminium reflector curves from the transport duct to the base of the diffuser 14, touching the lower surface composed of an OLF (Optical Lighting Film) resting on a sheet of opaline polycarbonate which represents the emission surface.
[0015] The sun light sensor 11 is an active system, capable of following the course of the sun, following the height on the horizon during the day to take full advantage of the receiving capacities of the system.
[0016] This result is obtained by servomechanisms (electrical actuators), controlled by sensors and microcomputers, which allow the sun light sensor 11 outside the building to rotate vertically from the top to the bottom and vice versa, following the height of the sun on the horizon by means of a PLC which controls a stepping motor (which are not shown in the figures for simplicity).
[0017] More specifically, figure 1 shows the sun light sensor 11, with its Fresnel lens 12 and the inlet of the transport duct 13; also visible are two transparent side walls 24 and 25 and a transparent rear wall 26, in addition to a non-transparent front wall 27 equipped inside with a reflecting element, all elements that complete the structure of the sun light sensor 11.
[0018] Moreover, it can be seen that the body of the sun light sensor 11 is rotatable by means of a lever 20 activated by the piston 21.
[0019] The focal point is about 40 cm in distance from the lower surface of the lens (which is also the depth of the sun light sensor 11), where the transport duct 13 is positioned, in turn coated in highly reflective material, and composed of a box-shaped component of 180 cm in width and 10 cm in height, with variable depth according to the thickness of the wall in which it is recessed.
[0020] The Fresnel film lenses 12 are composed of a prismatic film in which the inclination of the micro-prisms arranged on the material varies gradually as they move away from the central point.
[0021] As previously mentioned, the Fresnel lens 12 is positioned on the cylindrical surface of the sun light sensor 11.
[0022] With this structure of the lens 12, the result obtained is of a lens that completely follows the rules of optical geometry but which has the thickness of a film (about 0.5 mm).
[0023] The Fresnel lens 12 can thus produce an extremely concentrated laminar flow, increasing the efficiency of the system, with a transmission coefficient just below 100%, so that there is very little loss due to absorption.
[0024] Figure 4 shows a schematic view of the light carrier system for natural light 10, in an operating mode in which the light coming from outside is not sufficient for internal illumination.
[0025] In this mode, a battery of lamps 23 is switched on and their light is reflected by a mirror 22 and conveyed inside the diffuser 14.
[0026] However, in the case in which the external light is sufficient, the lamps 23 are switched off and the mirror 22 is made to rotate to leave the transport duct 13 free.
[0027] The characteristics of the light carrier system for natural light contemplated in the present invention and the advantages of this system will become apparent from the description.
[0028] In particular, the reduced number of components of the system is noted; this fact has positive influences on its management and long-term maintenance.
[0029] The dimensional impact in the section of about 25 cm in height is considerably smaller in relation to prior art types of passive sun light sensors. In fact, these sun light sensors require a section with overall dimensions varying from a minimum of 30-40 cm to a maximum of 50-60 cm, with negative influences on the structural volumetric management of the building and integration of the system with plant layout networks.
[0030] It is apparent that the instrument with these reduced dimensions is similar to the height of conventional illumination instruments, which may or may not be perfectly recessed in false ceiling systems.
1. Light carrier system for natural light (10), characterised in that it is provided with a semicylindrical sun light sensor (11), equipped with a Fresnel
lens (12) consisting of a film and with linear concentration and, where the aforesaid
sun light sensor (11) is located outside the building housing the room to be lit,
a transport duct (13) and a diffuser (14), where inside the unit composed of the transport
duct (13) and the diffuser (14), there is a reflector, while the emission surface
of the aforesaid diffuser (14) is composed of an OLF (Optical Lighting Film) resting
on a sheet of transparent polycarbonate and in that the aforesaid sun light sensor (11) is capable of following the course of the sun,
actively, following the height on the horizon during the day to optimally take advantage
of its capacities to receive light.
2. Light carrier system for natural light, as claimed in claim 1, characterised in that the aforesaid sun light sensor (11) is rotatable by means of servomechanisms, controlled
by sensors and microcomputers, which allow the sun light sensor (11), positioned outside
the building, to rotate vertically from the top to the bottom and vice versa following
the height of the sun on the horizon by means of a PLC which controls a stepping motor.
3. Light carrier system for natural light, as claimed in claim 1 or 2, characterised in that the aforesaid sun light sensor (11) has two transparent side walls (24, 25) and a
transparent cylindrical rear wall (26), in addition to a non-transparent front wall
(27) equipped inside with a reflecting element.
4. Light carrier system for natural light, as claimed in claim 1, characterised in that it is provided with a battery of lamps (23), whose light is reflected by a mirror
(22) and conveyed inside the diffuser (14), when the external light is not sufficient
for internal illumination.