Lighting system using natural and artificial light

Abstract

 The present invention relates to a combined solar and artificial lighting system, wherein a sunlight collector is positioned on the exterior of a building and is used to collect sunlight and transfer this into a transferral means for providing the light into the interior of a building. At the interior of the building a plurality of combined solar and artificial light luminaries are located and are adapted such that they provide the daylight collected into the building interior. Additionally, the combined luminaires are possessed of artificial lighting means which can be used to augment the natural daylight passing through the system.

Description

BACKGROUND TO THE INVENTION

[0001] Current trends in environmental friendliness are leading people to look for renewable and sustainable means of generating power and the like to reduce the environmental impact. Further, low energy usage lighting systems are being developed to reduce the power consumption of providing light to the interior of buildings. Not only do these low power consumption lighting means save money for the user in the long run, but also the reduction in power usage has beneficial effects for the environment. One further method of providing cheap and renewable light into the interior of a building, is to collect daylight from the exterior of the building and in some way provide it into the rooms in the interior. Obviously, the simplest form of this is that of the skylight, wherein a hole exists in the roof of the building, and this is covered by some form of transparent cover. Daylight is therefore able to pass through this transparent cover and light the inside of the building. Obviously, such a simple system can only provide light in the region of the skylight, which has led to the development of more complex light routing systems which can direct light from the exterior of the building, through the interior, to the desired part.

[0002] Known systems of collecting daylight and transferring this through to a selected area of the interior of the building are often extremely complex, or suffer from undesirable losses of the light. Further problems exist in such systems with fluctuations in the amount of light present on the exterior of the building, affecting the amount of light on the interior of the building.

SUMMARY OF THE INVENTION

[0003] The above problems are solved by the combined solar and artificial lighting system of the current invention. In one aspect of the lighting system, a collector of sunlight is incorporated and can be positioned on the exterior of a chosen building. Such a collector advantageously comprises a structure for efficiently collecting large quantities of daylight. Attached to the sunlight collector is a means for transferring the light collected to the interior of a building. At the interior end of the transferral means is provided a combined luminaire which is suitable for providing solar and artificial light into the building interior. These combined luminaries, when a plurality are provided, interact with the end of the transferral means to receive the light travelling therethrough.

[0004] Within the combined luminaire there is provided one or more lighting means for generating an artificial light in a known manner. Further, a light sensor is in connection with the combined luminaire, and is positioned in the interior of the building for monitoring the amount of light therein. The combined luminaire is specifically adapted such that the amount of light generated from the artificial light means is regulated so as to augment the amount of daylight which passes through the light transferral means. This regulation and augmentation is achieved by monitoring the amount of light in the interior of the building by means of the light sensor, and when this is insufficient for a required lighting level, the artificial light means are switched on. Further, the artificial light means are operated such that the amount of light they generate is varied so as to provide a constant amount of light from the combined luminaire into the building interior irrespective of the amount of natural daylight.

[0005] In the above, it is conceived that the means for transferring the light from the sunlight collector to the interior of the building can be provided by a light tube. Such a light tube being connected between the sunlight collector and the one or more combined luminaires. As a further aspect, it is possible for the light tube to be constructed such that there are no bends within it that are greater than 90°. A preferred structure actually has the light tube being possessed with no bends greater than 60°.

[0006] It is also possible for the light transferral means to simply be a collar which connects directly between the sunlight collector and the combined luminaire. In essence, this generates a system which is intended for very short spans between the exterior and the interior of the building, such that a sunlight collector is virtually connected directly to the combined luminaire.

[0007] Instead of the light tube comprising the light transferral means, it is possible for the transferral means to comprise one or a plurality of fibre optic cables. Such provision of fibre optic cables is advantageous, as it allows the transferral of light from the exterior to the interior of the building in buildings where there a shortage of space for such transferral means.

[0008] A further system is conceived which is similar to that above; in this case, however the light transferral means are provided by a light tube, which connects between the sunlight connector and the combined luminaries. In particular, this light tube is designed such that it comprises no bends which are greater than 90°. Provision of a light tube with reduced bending, and indeed no large angle bends, is advantageous as there is a reduction in the amount of natural light which is lost whilst passing through the light tube. In this option, it is not necessarily required to have the light sensor adjusting the power and amount of light from the artificial light means.

[0009] In this further system, as with the first described system, it is a preferable aspect to provide the light tube with bends that are preferably not greater than 60°. Further, as with certain aspects relating to the first described system, it is conceived that the light tube may be comprised of a highly reflective coating on the internal surface of a tube-like body.

[0010] With reference to both of the above described systems, the sunlight collector can comprise a Fresnal lens which is utilised to focus the collected sunlight into the light transferral means. Additionally, in order to improve the amount of collected sunlight, it is possible to provide the sunlight collector with some form of mounting which allows the collector to move in order to track the brightest light at the exterior of the building.

[0011] Within the combined luminaire of the above systems, it is possible to provide the artificial lighting means as spotlights, which are positioned such that they do not interfere with the natural light which is exiting the light transferral means. Instead of using spotlights, however, it is also possible to provide the light by means of fluorescent strips. If such fluorescent strips are being used, it is preferable to use T5 lamps, as these are of a very narrow construction and do not block a great deal of the light exiting the transferral means. If fluorescent strips are provided, it is further very useful to provide some form of reflector such that the light which is generated by the fluorescent strip is directed into the interior of the room, and no light escapes from the interior to the exterior of the building via the light transferral means. Reflectors may also be provided with the spotlights.

[0012] As the combined luminaire may be providing both natural and artificial light into the building interior, it is advantageous to provide a cover on the luminaire. Preferably this cover has a diffusive nature such that the light is generally combined to give a uniform light into the building interior. Additionally, this cover is advantageously provided with a dust-tight seal, such that no dust or other particulate enters the luminaire and light transferral system. Finally, the cover may be made of a thermally insulating material such that heat transfer through the cover is reduced. A further dust shield may be included within the combined luminaire structure at the end of the light transferral means. Such a dust shield additionally helps to reduce the amount of dust entering the transferral means, and therefore improves the transfer of light.

[0013] The light sensor is preferably located within the interior of the building in a region near the combined luminaire. Further, this light sensor is adapted to measure the light in the building interior and operate the artificial light means to ensure that the light contribution from these is enough to give a satisfactory light level in the building. It is conceived that an advantageous position for the sensor would be the ceiling near the combined luminaire, wherein the sensor would be calibrated such that the light measured that the ceiling would give a known light level at the working level. It is not necessary to provide a light sensor for each of the luminaires, and it may be useful to provide one light sensor for multiple combined luminaires such that each will operate in the same way. As a final option, the combined luminaire can be connected to the existing lighting electric circuitry of the building, or can readily be connected to the mains electricity.

[0014] A final aspect of the current invention is that of the combined solar and artificial light luminaire. Such a luminaire would be provided with one or more artificial light means, such that they may provide artificial light into the building interior. A light sensor is positionable within the building interior, and monitors the level of light in the building interior. The combined luminaire also is attachable or is adapted to interact with the end of a light transfer means for transferring light from the exterior to the interior of a building. The light sensor is adapted such that it will monitor the light in the building interior and adjust the output of the artificial light means, such that a desired level of lighting is provided in the building interior.

[0015] Further advantageous embodiments of the artificial lighting system are discussed in the following detailed description of the invention. Additionally, the independent claims describe the aspects and embodiments of the current combined solar and artificial lighting system, with the dependent claims describing further preferred aspects and embodiments.

BRIEF DESCRIPTION OF THE FIGURES

[0016] 

Figure 1

shows a perspective cut away view of the combined solar and artificial lighting system of the current invention.

Figure 2

shows a cross-sectional view of one possible embodiment of the invention.

Figure 3

shows a cross-sectional view of another possible embodiment of the invention.

DETAILED DESCRIPTION OF INVENTION

[0017] Looking at the Figures, perspective cut away and cross-sectional diagrams of a combined solar and artificial lighting system 1 comprising many of the elements of the current invention can be seen. This lighting system 1 is shown extending from the roof of a building 2 through an area into an interior 4 of the building 2. Obviously, the external section of the lighting system 1 need not be in the roof of a building 2, but can also be positioned on any externally exposed surface. For example, a building which has a generally south-facing wall, could readily provide the point for the external side of the lighting system 1.

[0018] As can be seen in the Figures, a very simple example of the lighting system 1 is shown. In these examples, the exterior portion of the lighting system 1 is made-up of a sunlight collector 10, which is designed to collect the sunlight and general daylight from the outside 3 of the building 2. As is shown in the Figures, the sunlight collector 10 could be as simple as a covering over an entry system into the interior 4 of the building 2. Whilst such a system would clearly allow daylight to enter the lighting system 1, this is not the most efficient form of achieving such. One possible method for improving the capture of daylight is to incorporate some form of lensing system into the sunlight collector 10.

[0019] In particular, a fresnel lens 11 is considered advantageous, as this lens is of a generally compact construction, and can readily be incorporated within the sunlight collector 10. Further options for improving the collection of daylight, would be to incorporate a mirrored surface, which could accept and focus a large area of daylight into the lighting system 1.

[0020] Clearly, it is the sun which provides the majority of light, and therefore it is advantageous if the sunlight collector 10 can move and track the passage of the sun. This could readily be achieved by having the sunlight collector 10 provided on a movable platform or station, such that the lens 11 or other mechanism of collecting daylight were able to follow the track of the sun across the sky. It is conceivable that either the passage of the sun is approximated upon fitting the sunlight collector 10, and therefore the motion is programmed to follow approximately the path of the sun; or that some form of sensor is positioned on the sunlight collector 10, such that the position of the sun is accurately determined and the sunlight collector 10 moves accordingly.

[0021] Once the daylight has been collected by the sunlight collector 10, and possibly focussed by means of a fresnal lens 11, it enters the natural light transferral means 20. These transferral means 20 are considered to encompass any reliable mechanism whereby light can be transferred from the sunlight collector 10 to a delivery point with high efficiency. As can be seen in the Figures, these examples of the combined solar and artificial lighting system 1, incorporate a light tube 21. This light tube 21, is comprised of a tube-like body 22 which has a highly reflective internal coating 23 on the interior surface thereof. Obviously light which enters the one side of the light tube 21 will be reflected along the tube-like body 22 by the reflective internal coating 23. Use of a very good reflective surface for the internal coating 23, will dramatically improve the amount of light which transfers from one end of the light tube 21 to the other, and reduce losses substantially. Whilst in the Figures the light tube 21 is shown as a single slightly bent tube-like body 22, this is by way of example only. It is quite clear that if a single sunlight collector 10 is to be used to provide daylight into the combined solar and artificial lighting system 1, the natural light transferral means 20 could comprise numerous light tubes 21. For example, a single sunlight collector 10 could be connected to one end of a single light tube 21. At a point along the path of the light tube 21, it could branch into one or more secondary light tubes for transferring light to a plurality of destinations.

[0022] Whilst in the Figures the natural light transferral means 20 are shown as being a light tube 21, this is not the only possible option. For example, it is perfectly reasonable to replace all or some of the light tubes 21 with a series of fibre optic cables 24. Such fibre optic cables 24 are very well known in the art, and provide an extremely efficient mechanism for transferral of light from one end thereof to the other. The sunlight collector 10 could be specifically adapted such that the collected daylight is focussed, by means of lenses or mirrors or the like, to an entry to the first end of one or a plurality of fibre optic cables 24. These fibre optic cables 24 can then readily be integrated within a building for transferring light from the sunlight collector 10 to the interior 4 of the building 2.

[0023] If the combined solar and artificial lighting system 1 is being used with a light tube 21 as the natural light transferral means 20, it is advantageous to reduce the bending within the light tube 21. It is undesirable to have to incorporate a series of mirrors within the light tube 21, other than the reflective internal coating 23, to ensure that the light is sufficiently well transferred from one end of the light tube 21 to the other. One mechanism for achieving this, is to ensure that the light tube 21 does not have any bends which are greater than 90°. Indeed, it is further preferable that any bends provided in the light tubes 21 are no greater than approximately 60°. Clearly, reduction in the bending of the light tubes 21 allows for the light in the light tube 21 to progress from the exterior 3 to the interior 4 of the building 2. Large angles for bending in the light tubes 21, those greater than 90°, will tend to lead to some of the light in the light tube 21 being reflected back up the light tube 21 and generally toward the exterior 3 of the building 2. This is clearly undesirable. Additionally, having bends which are less than 90°, and preferably less than 60°, will mean that it is not necessary to further incorporate additional mirrors into the light tube 21 to avoid this reflection along the light tube 21 toward the exterior 3 of the building 2.

[0024] It is conceived that the light tube 21 could be comprised of a tube-like body 22 with a diameter of up to one metre. Obviously, the tube-like body 22 does not need to have a circular cross-section, and could in fact have any cross-section. For example, a square cross-section can increase the area of the light tube 21 for the same diameter. Such a light tube 21 will normally be fabricated from a rigid material that is able to provide a rigid structure. This is not necessarily vital, however, as the light tube 21 could also be provided by a more flexible tube-like body 22, and the fixing points at either end of the light tube 21 support and anchor the tube 21. Obviously, if the system is to be used with fibre optic cables 24, the diameter of the natural light transferral means 20 will be substantially reduced, and may even be as low as a few millimetres.

[0025] As can be seen in the Figures, the basic design is to provide a means for transferring light from the exterior 3 to the interior 4 of a building 2. The Figures merely show examples wherein the end of the natural light transferral means 20 is on the top floor of the building 2. Obviously, it is perfectly possible to transfer the daylight from the exterior 3 of the building 2, to a different floor. Providing the daylight to an interior floor or the building 2, requires that the natural light transferral means 20 be routed through the building structure. Such routing can be achieved through wall cavities or lift shafts. If this system is to be incorporated within a building that currently exists, it is rather more practical to provide the natural light transferral means 20 as fibre optic cables 24, as these generally have a reduced diameter and can be more easily routed through the building.

[0026] One further possibility which is not shown in the Figures, is to essentially remove the natural light transferral means 20. Obviously, the longer the transferral means 20, the greater the possibility for losses of daylight in the system. It is clearly advantageous to provide the natural light transferral means 20 as being as short as possible, as an increased length of light tube 21 or fibre optic cables 24 will lead to losses of light. It is possible, therefore, to form a combined solar and artificial lighting system 1 wherein the sunlight collector 10 feeds directly to the interior 4 of the building 2 without using a long natural light transferral means 20. For example, some form of skylight could be used for interacting with the sunlight collector 10 and the interior side of the combined solar and artificial lighting system 1.

[0027] The interior portion of the combined solar and artificial lighting system 1 is comprised of one or more combined solar and artificial light luminaires 30. These combined solar and artificial light luminaires 30 are intended to interact with and/or be connectable with one end of the natural light transferral means 20. Clearly if the natural light transferral means 20 branch, as discussed above, multiple luminaries 30 are connected to the multiple ends. As can be seen in the Figures, the combined luminaire 30 is shown as interacting with one end of the light tube 21. If the natural light transferral means 20 comprises fibre optic cables 24, clearly the combined luminaire 30 needs to be adapted such that it takes the daylight travelling through the fibre optic cable 24 and efficiently introduces it into the interior 4 of the building 2. Also, as discussed above, if the natural light transferral means 20 does not comprise a light tube 21 or fibre optic cable 24, but rather is a skylight-type of unit, the sunlight collector 10 can essentially connect or interact directly with the combined luminaire 30. In this example, the natural light transferral means 20 can essentially be considered as some form of collar or connecting means between the sunlight collector 10 and the combined luminaire 30.

[0028] As can be seen in the Figures, the combined solar and artificial light luminaire 30 comprises the outlet of the natural light transferral means 20. In the examples shown, the natural light transferral means 20 comprises the light tube 21, and this light tube 21 essentially terminates at an upper side of the combined luminaire 30. Light which is transferred through the light tube 21 exits the light tube 21 and is provided to the interior 4 of the building 2. Obviously, if the natural light transferral means 20 are provided by fibre optic cables 24, some form of lensing system would be incorporated into the combined luminaire 30, such that the light is spread out upon exiting the end of the fibre optic cable 24 and the combined luminaire 30 provides a substantial amount of daylight into the building interior 4.

[0029] In the case where the combined luminaire 30 comprises the end of a light tube 21, it is advantageous to provide some sort of dust shield 39. The dust shield 39 is intended to provide an end to the light tube 21, and to stop dust and other particulate material from entering the light tube 21. Obviously, dust within the light tube 21 will tend to settle on the reflective internal coating 23, and therefore reduce the amount of light which is transferred. It is further possible to provide a general cover 36 on the front of the combined luminaire 30, the front being the side which is presented to the interior 4 of the building 2. Providing the cover 36 with a dust-tight seal 38, is advantageous as this stops dust and particulate material from entering the combined luminaire 30. Further, a combination of a cover 36 with a dust-tight seal 38 and the dust shield 39, will aim to completely stop any dust or particulate material from entering the light tube 21.

[0030] One final feature of the cover 36 of the combined luminaire 30, is that it provides a sufficient thermal shield. Obviously, a light tube 21 as shown in the Figures will readily transmit heat from the interior of the building to the exterior of the building. This is not especially advantageous in winter, and therefore the cover 36 can advantageously be made of a thermally insulating material to stop the transfer of heat. Additionally, if a combined luminaire 30 comprises a dust shield 39, this can also be provided by a thermally insulating material to try and reduce the amount of heat which passes therethrough. Further, this can be advantageous if the exterior 3 of the building 2 is very warm, and it is undesirable to transfer too much heat through the natural light transferral means 20 to the interior 4 of the building 2.

[0031] In addition to the combined solar and artificial light luminaire 30 being designed to provide the exit from the natural light transferral means 20, they also comprise artificial light means 31. Obviously, the amount of light available from daylight is dependent both on the time of day and weather. In bright sunny conditions, a great deal of light will be collected by the sunlight collector 10 and transferred by the natural light transferral means 20 to the combined luminaire 30 and then into the interior 4 of the building 2. When the weather is cloudy or it is night time, little or no daylight is collected by the sunlight collector 10, and the interior 4 of the building 2 is not sufficiently well lit. In order to ensure that the interior 4 of the building 2 is well lit during bad weather and night time, the artificial light means 31 can add additional light into the combined luminaire 30. The additional light from the artificial light means 31 is either combined with the light exiting the natural light transferral means 20, or when no such light is within the natural light transferral means 20, the light from the artificial light means 31 provides the only light to the interior 4 of the building 2.

[0032] At times when light is required from the artificial light means 31 to supplement the amount of natural light exiting the natural light transferral means 20, it is advantageous for these sources of light to be appropriately mixed prior to or as being provided into the building interior 4. The simplest mechanism for mixing the artificial and natural light, is to provide the cover 36 with a diffuser 37. If the cover 36 has a diffuse surface, which can be of any well known form, the natural and artificial light will be satisfactorily mixed, and a uniform light provided to the building interior 4. One mechanism of providing a diffuser 37, is to roughen one side of the cover 36, such that the light from both the natural and artificial means scatters as it passes through the cover 36. Another mechanism, is to provide the cover 36 with a multiple lens diffuser 37, such that the light is reflected, refracted and directed in different directions, such that the natural and artificial light is combined. Diffusers 37 are well known in the art, and it is considered that any of these well known options would be equally appropriate here.

[0033] As can be seen in the two options shown in the Figures, it is quite possible for the artificial light means 31 to comprise different structures. As is clear from Figures 1 and 2, the artificial light means 31 can comprise fluorescent strips 34. These fluorescent strips 34 are positioned across the interior of the combined luminaire 30, and are provided so as to augment the amount of light exiting the natural light transferral means 20, should the external light be insufficient for lighting the interior 4 of the building 2. Obviously it is advantageous to interfere minimally with the light exiting the natural light transferral means 20, and so the artificial means 31 should either not be positioned in front of the exit of the natural light transferral means 20 as shown in Figure 2, or at the very least only marginally interfere with such as shown in Figure 1. In the case of the fluorescent strips 34 seen in Figures 2, it is anticipated that these strips 34 could be provided outside of the region of exit of light from natural light transferral means 20. On the other hand, if more fluorescent strips are required, it is possible to provide these fluorescent strips 34 in front of the exit of the natural light transferral means 20, but keeping these strips 34 to a minimum number. Advantageously, the fluorescent strips 34 could be provided by T5 type fluorescent strips 34. These T5 fluorescent strips 34, comprise fluorescent strips 34 which have a very small diameter, and therefore do not block much of the natural light exiting the natural light transferral means 20. It is further advantageous to provide fluorescent strips 34 for the artificial light means 31, as these generally have a high efficiency and low power consumption.

[0034] As can be seen in Figure 3, it is also possible to provide the artificial light means 31 by means of spotlights 33. The advantage of providing spotlights 33, is that these can be incorporated into the body of the combined luminaries 30 at a position away from the exit of the natural light transferral means 20. As shown in Figure 3, spotlights are provided in the corners of the combined luminaire 30, which are not in the path of the natural light exiting the natural light transferral means 20. Again, it is advantageous if these spotlights 33 are designed such that they can comprise low energy fluorescent bulb type lamps, so as to improve the energy efficiency of the system.

[0035] One further important and advantageous feature which may be included in the combined solar and artificial light luminaires 30, is that of reflectors 35 for the artificial light means 31. Obviously, when light is being generated by the artificial light means 31, it is important that this light is directed toward the interior 4 of the building 2. The natural light transferral means 20 acts equally well to remove light from the interior 4 of the building 2 and provide this to the exterior 3. In order to avoid this, provision of reflectors 35 on the artificial light means 31 will mean that any light generated by these artificial light means 31 is directed into the building 2 and not through the natural light transferral means 20 to the exterior 3 of the building 2. In the case of the spotlights 33 seen in Figure 2, this is readily achieved by simply having a reflective housing or baffle into which the spotlight 33 bulb fits. In the case providing fluorescent strips 34, either the upper surface of the fluorescent strips 34 can comprise a highly reflective surface for directing the light only toward the interior 4 of the building 2, or a separate reflector 35 is provided just above the fluorescent strip 34 for directing the light to the interior 4 of the building 2.

[0036] One final feature of the combined solar and artificial lighting system 1, is the optional provision of a light sensor 32 which is positionable within the interior 4. This light sensor 32 is intended to measure the light within the interior 4 of the building 2, in order to ensure that enough light is present within the building interior 4. As has been discussed above, daylight from the exterior 3 of the building 2 will vary depending upon the weather and time of day. The requirements for light in the interior 4 of the building 2, does not change, and therefore it is necessary to augment the natural light with that from the artificial light means 31. In order to provide a reasonable amount of light within the building interior 4, the light sensor 32 monitors the amount of the light in the building interior 32 and adjusts the amount of light from the artificial light means 31 accordingly. When the natural light exiting the natural light transferral means 20 drops below an acceptable level, the light sensor 32 monitors and recognises this and therefore acts within combined luminaire 30 to cause the artificial light means 31 to switch on. Obviously, once the natural light being provided by the natural light transferral means 20 increases again, the light from the artificial light means 31 may not be needed to provide sufficient lighting to the building interior 4, and therefore the artificial light means 31 can be switched off. The light sensor 32 constantly monitors the amount of light in building interior 4, and if this exceeds a point and the artificial light means 31 are still on, the light sensor 32 causes the combined luminaire 30 to switch off the artificial light means 31.

[0037] It is particularly advantageous to maintain a near constant level of light within the building interior 4. As such, a preferred design of the combined solar and artificial light luminaire 30, has artificial light means 31 which can produce a variable amount of light. The light sensor 32 monitors the amount of light within the building interior 4, and adjusts the amount of light being generated by the artificial light means 31 to ensure that the light exiting the combined luminaire 30 remains at a constant. For example, on a bright sunny day the amount of light being provided by the natural light transferral means 20 may be fully sufficient for lighting the interior 4 of the building 2. As such, the artificial light means 31 are not switched on at all. If the amount of light begins to drop, it may be that the total light provided by the natural light transferral means 20 is not sufficient to provide a required amount of light to the building interior 4. At this point, the light sensor 32 detects this reduction in light, and switches on the artificial means 31 to generate a sufficient amount of light to maintain required light level. In this way, the combined luminaire 30 provides an active component which ensures that the amount of light in the building interior 4 remains constant. Obviously, when the light present in the exterior 3 of the building 2 drops very low, for example at night time, the artificial light means 31 will be run at a maximum level, such that the light within the building interior 4 is still acceptable.

[0038] As can be seen in Figure 1, the light sensor 32 may be incorporated directly into the combined luminaire 30. That is, the light sensor 32 monitors the amount of light actually to the side of the combined luminaire 30 and is calibrated such that the amount of light measured here is known to correspond with the amount of light at the working level in the building interior 4. Such calibration is readily achievable, and allows for a compact combined luminaire 30 and light sensor 32, which will maintain the required amount of light at the working level of the building interior 4.

[0039] Whilst the Figures show a single light sensor 32 per combined luminaire 30, it is quite possible to have one light sensor 32 being connected to a plurality of combined luminaries 30. If a plurality of combined luminaries 30 are provided in one area of the interior 4 of a building 2, it is quite likely that each of the artificial light means 31 of each combined luminaire 30 should be generating the same amount of light as each other. As such, a single light sensor 32 could be adapted to operate the amount of light from the artificial light means 31 of a plurality of combined luminaries 30, thereby reducing the number of light sensors 32 required.

[0040] It is anticipated, that the combined luminaries 30 will be integrated within the ceiling of a building interior 4, as shown in the Figures. Obviously, it is equally possible to provide the combined luminaries 30 on a sidewall of a building interior 4, should this be more desirable. If this is the case, obviously the light sensor 32 is calibrated such that it maintains the required amount of light by augmenting the natural light with that from the artificial light means 31. Further, the combined luminaries 30 can be operated either by mains electricity, or by integrating these within the standard lighting circuitry provided in an already existing building. Also, the combined luminaries 30 as shown in the Figures, are intended to fit readily within the ceiling of a building interior 4. That is, many modern buildings have suspended ceilings, and are provided with standard luminaries, for providing light to the rooms. The combined luminaries 30 of the current invention are shaped and sized so that they can readily replace existing luminaries in a building 2.

[0041] The above described combined solar and artificial lighting system 1 obviously comprises numerous features therein. It is intended that a degree of flexibility is available in this combined lighting system 1, and therefore it is possible to provide a system 1 comprising all or only a few of the above described features. As such, a combined lighting system 1 drawing on many of the options described above can be constructed as required at the point of use, and no combination of features is considered as particularly important for the appropriate operation of the combined lighting system 1. For example, a combined luminaire 30 could combine both of the artificial lighting means 31 described above, that is both fluorescent strips 34 and spotlights 33.

Claims

1. A combined solar and artificial lighting system (1) comprising:

a sunlight collector (10) positionable outside (3) of a building (2) for collecting sunlight;

one or more combined solar and artificial light luminaires (30), positionable within the interior (4) of a building (2);

a natural light transferral means (20) adapted to transfer the light from the sunlight collector to the one or more combined luminaires (30); wherein

the one or more combined solar and artificial light luminaires (30) interact with and/or are connectable with one end of the natural light transferral means (20) for providing the collected sunlight into the building interior (4), the one or more combined solar and artificial light luminaires (30) further comprising:

one or more artificial light means (31) arranged to provide artificial light into the building interior (4), and

a light sensor (32) positionable within the building interior (4); wherein further

the combined solar and artificial light luminaire (30) is adapted to maintain the same amount of light in the building interior (4) by adjusting the level of light from the artificial light means (31) on the basis of the light detected by the light sensor (32).

2. The lighting system (1) according to claim 1, wherein the natural light transferral means (20) comprise a light tube (21) for connecting between the sunlight collector (10) and the one or more combined solar and artificial light luminaires (30).

3. The lighting system (1) according to claim 2, wherein the light tube (21) does not have any bends in it which are greater than 90°.

4. The lighting system (1) according to claim 1, wherein the natural light transferral means (20) comprises a fixing means or collar (25) for the direct connection of the sunlight collector (10) to one or more of the combined solar and artificial light luminaires (30).

5. The lighting system (1) according to claim 1, wherein the natural light transferral means (20) comprises one or more fibre optic cables (24).

6. A combined solar and artificial lighting system (1) comprising:

a sunlight collector (10) positionable outside (3) of a building (2) for collecting sunlight;

one or more combined solar and artificial light luminaires (30), positionable within the interior (4) of a building (2);

a natural light transferral means (20) comprising a light tube (21) connected between the sunlight collector (10) and the one or more combined solar and artificial light luminaires (30), wherein the light tube (21) does not have any bends in it which are greater than 90°, and further

the one or more combined solar and artificial light luminaires (30) interact with and/or are connectable with one end of the light tube (21) for providing the collected sunlight into the building interior (4), the one or more combined solar and artificial light luminaires (30) further comprising:

one or more artificial light means (31) arranged to provide artificial light into the building interior (4), and

a light sensor (32) positionable within the building interior (4).

7. The lighting system (1) according to any of claims 2, 3 or 6, wherein the light tube (21) preferably does not have any bends in it which are greater than about 60°.

8. The lighting system (1) according to any of claims 2, 3, 6 or 7, wherein the light tube (21) comprises a tube like body (22) which is internally coated with a highly reflective internal coating (23).

9. The lighting system (1) according to any of the preceding claims, wherein the sunlight collector (10) comprises a Fresnel lens (11) for focussing the collected light into the natural light transferral means (20).

10. The lighting system (1) according to any of the preceding claims, wherein the sunlight collector (10) is movable about its mounting position so as to allow it to track the position of the brightest light or sun throughout the day.

11. The lighting system (1) according to any of the preceding claims, wherein the artificial light means (31) comprise one or more spotlights (33) which are positioned in the combined solar and artificial light luminaire (30) in a position which does not interfere with the end of the natural light transferral means (20).

12. The lighting system (1) according to any of claims 1 to 10, wherein the artificial light means (31) comprise fluorescent strips (34).

13. The lighting system (1) according to claim 12, wherein the fluorescent strips (34) preferably comprise T5 lamps.

14. The lighting system (1) according to either of claims 12 or 13, wherein the fluorescent strips (34) are provided with reflectors (35) which are positioned such that the light from the fluorescent strips (34) is stopped from entering the natural light transferral means (20) and is instead reflected into the building interior (4).

15. The lighting system (1) according to any of the preceding claims, wherein the combined solar and artificial light luminaire (30) is provided with a cover (36) which is preferably comprised of a diffuser (37) for combining the natural light from the natural light transferral means (20) with light from the artificial light means (31), if generated, as it passes through the cover (36) to provide a uniform light to the building interior (4).

16. The lighting system (1) according to claim 15, wherein the cover (36) is provided with a dust tight seal (38) to stop dust or other particulates from entering the combined solar and artificial light luminaire (30) and the natural light transferral means (20).

17. The lighting system (1) according to either of claims 15 or 16, wherein the cover is comprised of a thermally insulating material for reducing heat transfer through the cover.

18. The lighting system (1) according to any of the preceding claims, wherein the combined solar and artificial light luminaire (30) comprises a highly transparent dust shield (39) which is positioned at the interaction or connection point with the natural light transferral means (20) for stopping dust or other particulates from entering the natural light transferral means (20).

19. The lighting system (1) according to any of the preceding claims, wherein the light sensor (32) is located such that it will be able to measure the light in the interior (4) of the building (2) in the region of the combination solar and artificial luminaire (30), and is adapted to operate the artificial light means (31) to ensure that the light contribution from the artificial light means (31) offsets a reduction in the natural light from the natural light transferral means (20).

20. The lighting system (1) according to any of the preceding claims, where the light sensor (32) is located on the ceiling of the building interior (4) and is calibrated such that it will operate the artificial light means (32) so as to maintain a desired luminance at the working level of the building interior (4).

21. The lighting system (1) according to any of the preceding claims, wherein each of the one or more combined solar and artificial light luminaires (30) is provided with a light sensor (34) for individual control.

22. The lighting system (1) according to any of the preceding claims, wherein several of the one or more combined solar and artificial light luminaires (30) use one light sensor (32) for control of their artificial light means (31).

23. The lighting system (1) according to any of the preceding claims, wherein the one or more combined solar and artificial light luminaires (30) and light sensor (34) are powered using either the lighting circuitry of the building (2) or normal mains electricity.

24. A combined solar and artificial light luminaire (30) comprising:

one or more artificial light means (31) arranged to provide artificial light into the building interior (4), and

a light sensor (32) positionable within the building interior (4); wherein

the combined solar and artificial light luminaire (30) interacts with and/or is connectable with one end of a natural light transferral means (20) which is for providing collected sunlight from an outside (3) of a building (2) to the combined solar and artificial light luminaire (30); wherein further

the combined solar and artificial light luminaire (30) is adapted to maintain the same amount of light in the building interior (4) by adjusting the level of light from the artificial light means (31) on the basis of the light detected by the light sensor (32).

Drawing