AU2013270465A1 - Light Spill Controller - Google Patents

Abstract

A light spill control device comprising: a support surface for associating the device with the visor of a luminaire, and at least one baffle associated with the support surface, wherein the at least one baffle is at least partially enclosed by the visor of the luminaire. 21 b 15a 15b 21a 31b 1 1 9a x27 \9a 31Fa 329 9b FIGURE 3(b)

Description

P/00/011 Regulation 3.2(2) AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Application No. Lodged: Invention Title: LIGHT SPILL CONTROLLER The following statement is a full description of this invention, including the best method of performing it known to: 2 LIGHT SPILL CONTROLLER FIELD OF INVENTION [0001] The present invention relates to the field of lighting, particularly lighting assemblies and fixtures of the type known as 'exterior luminaire'. [0002] In one particular aspect the present invention relates to a spill control device for a light assembly, that is, a device that controls the direction(s) in which light spills out from artificial illumination. [0003] In one particular aspect the present invention is suitable for use in conjunction with outdoor lighting of the type found in public areas such as parks and gardens, sports and leisure areas, and thoroughfares such as roads, streets and tunnels. [0004] It will be convenient to hereinafter describe the invention in relation to street lighting, however it should be appreciated that the present invention is not limited to that use only as it may also be used for other purposes such as the control of illumination spilling out from playing fields or stadiums for sporting events, flood lighting at industrial sites for security, and light spill from 24 hour work sites such as ports and construction zones. [0005] The term 'luminaire' as used herein is a term of the art that includes a lighting assembly comprising a light source (lamp), a reflector for directing the light, an aperture covered by a visor which acts as a lens, an outer casing for lamp alignment and protection, an electrical ballast and connection to a power source. BACKGROUND ART [0006] It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention. Further, the discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art problems by the inventor. Moreover, any discussion of material such as documents, devices, acts or knowledge in 3 this specification is included to explain the context of the invention in terms of the inventor's knowledge and experience and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein. [0007] The purpose of outdoor lighting is to increase visibility of hazards, enhance safety, improve public amenity, provide character, accent, encourage patronage of public spaces and increase security. Outdoor lighting is commonly used for a wide range of applications including thoroughfares such as streets, footpaths and roadways, public places such as car parks, playgrounds, municipal buildings and municipal parks, work sites, and homes. [0008] Effective outdoor lighting has minimal light projecting vertically. Upward shining light doe little to provide safety or security, and is the primary sours of 'sky glow' lighting pollution. Effective lighting also projects a minimal of light outwards. Outward shining light creates glare, a potential visibility hazard for motorists, cyclists and pedestrians. Furthermore, effective lighting is mostly projected downwards to provide the visibility level required for safety, security and recreation. [0009] The use of electric street lighting dates back to the late 1 9 th century, when carbon arc lamps employing alternating current were used to ensure the electrodes burned down at the same rate. However due to their intense, harsh light and need for constant maintenance to replace burnt out carbon electrodes, by the start of the 20 th century they had been replaced by incandescent light bulbs. Incandescent bulbs remained in use until replaced by high-intensity discharge lamps, often operated in high voltage series circuits. Before the invention of photoelectric controls, a single switch or clock would be used to regulate the turning on and off of all the light in an entire district. [0010] Street lighting today typically uses high intensity discharge lamps or high pressure sodium lamps or in recent times, compact fluorescent tubes such as the T5, T8 or T12. The T5 lamp is particularly popular.

4 [0011] The "T" in lamp nomenclature represents the shape of the lamp - which is tubular. The number following the "T" usually represents the diameter of the lamp in eighths of an inch (1 inch equals 2.5 centimetres). T5 lamps are fluorescent lamps that are 5/8" of an inch in diameter. These lamps are approximately 40% smaller than T8 lamps, which are one inch in diameter, and almost 60% smaller than T12 lamps, which are 1 " in diameter. The T5, T8 and T12 also have different pin bases at each end of the lamp. [0012] Street lights are located at the top of poles in order to maximise the amount of light they cast onto the thoroughfare below. Since the 19th century street lighting has progressed from the use of straight, vertical poles of 3 to 4 metres in height to include much taller structures up to 10 metres in height, often curved at the top or including a bracket to locate the light closer to the centre of a thoroughfare. Many of these types of street lights are produced for use with a T5 fluorescent lamp including those sold under the registered Australian trade mark Greenstreet@ by Pierlite Pty Ltd, the street light described in Pierlite's Australian patent application AU 2004205200 and the street light described in Streetworx patent application AU-2009233600. [0013] Each type of luminaire has a characteristic light distribution pattern which depends on the configuration of the visor (which acts as a lens), reflector and the type and orientation of the individual optical elements. The light distribution patterns of luminaires can be expressed as 'isolux' or contour diagrams. The contours provide the points of equal illuminance around the luminaire, measured in units of foot candles or lux. Isolux diagrams can be used to assess the distribution characteristics of a luminaire in addition to determining lighting levels. Different distributions are used for different application. For example the distribution characteristics of a luminaire used to illuminate a sports ground will be different to those of an elongate luminaire used to project light vertically downwards from its position at the top of a pole onto a footpath. Even among streetlights, the distribution characteristics of an elongated luminaire will differ from a decorative luminaire on a pole for projecting light horizontally for 3600 as well as vertically upwards or downwards. [0014] For example, US patent application 2003/0053314 (Summerford et al) describes a luminaire for a sporting arena which is designed to concentrate light energy 5 where required, such as for television cameras, while eliminating unwanted stray or spill light to reduce viewer glare. The luminaire comprises a horizontally extending high intensity light source including an asymmetric parabolic shaped reflector having an exit aperture. Because the focal axis lies along an axis of an arc tube of the light source, the reflector acts as a collimator redirecting light from the light source into parallel rays from the exit aperture. A louver assembly is located within the exit aperture, including two groups of asymmetric louvres, each group being precisely angled. The louver assembly is necessarily of complex construction in order to control direct spill light from the arc tube, but not interfere with the arc of light from the arc tube which is emitted into the main beam of light rays from the reflector. [0015] JP 10-241419 (Matsushita Electric Works) describes a decorative luminaire of the type often located at the top of a short pole, typically 1 to 1.5 metres in height, for illuminating a path, steps or garden bed. The lamp of the luminaire is encircled by multiple annular louvers, arranged vertically, and inclined about 450 outward and downward. The luminaire is below normal eye-level, so the louvres are provided to decrease upper light flux that would otherwise cause glare and ensure that the outward and downward illumination is fit for intended purpose (eg making sure walkers can clearly see a step or pathway). [0016] Typically, for an elongate luminaire used as a street light, the distribution of light is referred to as being forwards, backwards, left or right of the luminaire, and aeroscreen when the light is directed downwards. This type of luminaire is significantly different to the arena and decorative luminaires described above. Furthermore, elongate luminaires used for external applications such as street lighting also have different illumination characteristics compared to internal elongate luminaires. [0017] For example, Canadian patent 2,593,720 (Acuity Brands, Inc) describes an overhead lighting system of a type commonly used in office buildings. The lighting system includes a housing mounted in a ceiling plane, a reflector tray in which is mounted a light source such as fluorescent tubes and a louver assembly. The louver assembly includes a plurality of longitudinal stringers transversely located relative to a plurality of substantially planar blade ribs. The top edge of the blade ribs fits flush with the reflector tray, while the bottom edge is flush with the plane of the ceiling. Thus, the 6 louver comprises a grid-like structure; the stringers and ribs interlocked to form a series of more or less equally sized rectangular openings. The louvre assembly is intended to minimise glare, without reducing illumination efficiency for workers in the office. [0018] External elongate luminaires are significantly different in design and application. One of the problems associated with street lighting is 'light pollution' or the spill of excessive light from a luminaire such that it causes nuisance or annoyance. For example, suburban residents may be annoyed by the spill of excess light from street luminaires onto their property, particularly if the windows of their residence are close to the sidewalk. [0019] In the past efforts have been made to control light spill by applying black paint to the outer surface of the visor of the luminaire. This approach is not aesthetically pleasing and the effectiveness of the paint decreases over time as it weathers. [0020] Other efforts to control light spill have included installation of a shield or boxing around one or more sides of the visor. One of the problems associated with shields or boxing attached to the exterior of a luminaire is that they can fall off. Exposure to the weather can cause fixtures to corrode, allowing the shield or boxing to detach from the luminaire and plummet many metres to the ground, potentially injuring those below. Time and expense is incurred replacing the shield. [0021] In another approach to control of light pollution, aluminium shields have been associated with the inside surface of the visor. While the shields could reduce light spill forwards and backwards, they could not control left, right or downward light spill. SUMMARY OF INVENTION [0022] An object of the present invention is to reduce light pollution in public areas. [0023] A further object of the present invention is to provide improved control of light spill.

7 [0024] A further object of the embodiments of the present invention is to improve the ease and speed with which existing lighting assemblies can be modified to control light spill. [0025] A further object of the present invention is to alleviate at least one disadvantage associated with the related art. [0026] It is an object of the embodiments described herein to overcome or alleviate at least one of the above noted drawbacks of related art systems or to at least provide a useful alternative to related art systems. [0027] In a first aspect of embodiments described herein there is provided a light spill control device comprising: - a support surface for associating the device with the visor of a luminaire, and - at least one baffle associated with the support surface, wherein the at least one baffle is at least partially enclosed by the visor of the luminaire. [0028] Typically the light spill control device can reduce light spill in one or more directions relative to the luminaire. In particular, the device is configured so that it can control light spill in one or more desired directions, that is, to the left, right, back, front or directly downwards from the luminaire, or combinations thereof. [0029] In a preferred embodiment, the device has an elongate support surface in association with an elongate baffle for controlling light spill to the left, or to the right, or to both the left and right of the luminaire. In another preferred embodiment, the device has two elongate support surfaces associated with either ends of two or more baffles located transverse to the support surfaces for controlling light spill to the front, back or directly beneath the luminaire. [0030] The light spill control device may be constructed of any convenient material or combination of materials, which are preferably non-conductive. In a particularly preferred 8 embodiment the baffles, and/or the support surfaces are of dark colour, such as matt black. [0031] Typically the device of the present invention is attached to a luminaire for external illumination, such as street lighting. A luminaire for street lighting typically has an elongate casing comprising a main body defining a port for receiving a mains cable, and a visor. Inside the casing is a reflector assembly for receiving at least one lamp, and a termination chamber. In a particularly preferred embodiment the lamp is a fluorescent lamp, particularly a T5 or T8. [0032] The visor incorporates within its structure a lens for optimising the casting of light from the lamp. The casing typically includes at least one integral hinge that permits movement of the visor from a first, closed position to a second, open position permitting full access to the light spill control device, the reflector assembly and termination chamber, without the visor disengaging from the main body. In a preferred embodiment, the light spill control device remains in association with the visor when the visor is in the second, open position. Thus, the light spill control device does not fall out of the luminaire when the visor is opened. [0033] Typically the support surface rests on a shoulder, flange, boss, pin or other suitably configured internal surface of the visor. The light spill control device may be integral with the visor. Securing means such as screws, pins, spring clips or combinations thereof may be used to removably attach the support surface to the visor. Alternately, during manufacture the visor and light spill control device may be formed as a singly unitary element. In an alternate embodiment, in use the light spill control device is not integral and is simply supported on the visor without the need for securing means. [0034] In a particularly preferred embodiment the light spill control device can readily be inserted or removed from the visor by electricians and electrical linesmen wearing cumbersome protective gloves. This is particularly useful during maintenance or for retrofitting the light spill control device to existing luminaires. [0035] The reflector assembly preferably includes an elongate reflector tray adapted to receive a single, double or compact fluoro lamp or more than one lamp without 9 restriction on wattage. Typically the reflector assembly will be substantially planar. This is in contrast to many of the reflector assemblies of the prior art, such as those appearing in the USA in the 1980's which had a cross sectional profile resembling two arched 'eyebrows', which tends to limit the assembly to accommodating only two globes/lamps. [0036] In one embodiment, the light spill control device is located intermediate the reflector assembly and the visor, and solely in contact with the visor. [0037] The termination chamber receives the mains cable and encloses electrical and electronic components. For example the termination chamber of a street light includes the photoelectric (PE) cell. A PE cell is typically present in each individual street light and controls the activation and deactivation of the street light based on the ambient light level. [0038] In a second aspect of embodiments described herein there is provided a lighting assembly having: - a casing comprising a main body defining a port for receiving a mains cable,

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a visor, - a reflector assembly for receiving at least one lamp, - a termination chamber, and - a light spill control device, wherein the light spill control device includes a support surface associated with the visor and at least one baffle associated with the support surface, wherein the at least one baffle is at least partially enclosed by the visor.

10 [0039] It is important that the baffles do not physically contact the lamps of the luminaire or otherwise interfere with their operation. When multiple baffles are in use, preferably the baffles are generally flat and U-shaped. [0040] Preferably the baffles are spaced to prevent direct visibility of the lamps from 250, or from 200, or from 50 behind the luminaire (ie for a street light, the end of the luminaire that is closest to residences). [0041] In yet a further aspect of embodiments described herein there is provided a system for control of light spill from an external luminaire, the system comprising at least one device according to the present invention associated with, and at least partially enclosed within the visor of a luminaire. [0042] In yet a further aspect of embodiments described herein there is provided a method of controlling a light spill in a luminaire including the step of installing a device according to the present invention in the luminaire. [0043] In a further aspect of embodiments described herein there is provided a method of manufacturing a light spill control device of the present invention including the steps of: - cutting a sheet of material to define at least one support surface and at least one transverse baffle, with an edge attached to the support surface, - twisting the at least one transverse baffle from 1 0 up to 900, and - forming attachment means in association with the at least one support surface. [0044] The attachment means may include, for example, holes for receiving a pin, boss or other projection from the visor. Typically the cutting and forming of attachment holes would be carried out by a laser. The device would then be ready for immediate installation in a luminaire by opening the visor, pressing the attachment holes in the 11 support surface onto lens pins on the visor, and securing the device using push-on spring washers. [0045] Other aspects and preferred forms are disclosed in the specification and/or defined in the appended claims, forming a part of the description of the invention. [0046] In essence, embodiments of the present invention stem from the realization that baffles could be configured for location within a luminaire in a position that advantageously controlled light pollution but did not interfere with operation of the luminaire. [0047] Advantages provided by the device of the present invention comprise the following: * can be installed as part of a new lighting structure or retrofitted to existing luminaires, * when retrofitted to existing luminaires there is no functional or performance penalties to the operation, maintenance or repair of the luminaire, * can be rapidly and economically retrofitted, * requires minimal maintenance, * can be readily accessed for repair, replacement or removal, * can be configured to avoid any risk of detaching and falling from a luminaire. [0048] Further scope of applicability of embodiments of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure herein will become apparent to those skilled in the art from this detailed description.

12 BRIEF DESCRIPTION OF THE DRAWINGS [0049] Further disclosure, objects, advantages and aspects of preferred and other embodiments of the present application may be better understood by those skilled in the relevant art by reference to the following description of embodiments taken in conjunction with the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the disclosure herein, and in which: Figure 1(a) to 1(d) depicts different attributes of outdoor lighting; Figure 2 illustrates light pollution (or 'spill light) effects from a luminaire; Figure 3(a) is an exploded view of a luminaire of a type preferred for use with the spill control device of the present invention, illustrating the major components; Figure 3(b) is a further exploded view of the luminaire of Figure 3(a) showing the components in greater detail; and Figure 3(c) illustrates the fully assembled luminaire of Figure 3(a) viewed from underneath (Fig. 3(c)(i), in cross section along AA' (Fig. 3(c)(ii)) and from the side (Fig. 3(c)(iii)); Figure 4 illustrates one embodiment of a device according to the present invention for controlling light spill from the left side or right side of a luminaire, the device shown in perspective view (Fig.4(a)), end or cross sectional view (Fig. 4(b)); and in cross-section (Fig.4(c)), located within the luminaire of Fig. 1; Figure 5 illustrates one embodiment of a device according to the present invention for controlling light spill from the front, back or directly downwards from a luminaire, the device shown in perspective view (Fig. 5(a)), end or cross sectional view (Fig.5(b)); top view (Fig.5(c)); and in cross-section (Fig.5(d)) located within the luminaire of Fig. 1; 13 Figure 6 illustrates isolux diagrams for a luminaire (known as an Enviro T5 Standard from Streetworx Pty Ltd) with and without spill control devices according to the present invention. Figures 6(a) and 6(b) are respectively, a polar diagram and an isolux diagram for the luminaire without any spill control. Figures 6(c) to 6(f) are isolux diagrams for the luminaire fitted with a transverse spill control device (Fig.6(c)), an aeroscreen spill control device (Fig.6(d)), a left side longitudinal spill control device (Fig.6(e)) and a right side longitudinal spill control device (Fig.6(f)); Figure 7 compares typical light spread of standard street light luminaires (Fig.7(a)) with the light spread from the same luminaire fitted with devices of the present invention. DETAILED DESCRIPTION [0050] Figure 1(a) to 1(d) depicts different attributes of outdoor lighting. Effective outdoor lighting has minimal light projecting vertically. Upward shining light doe little to provide safety or security, and is the primary sours of 'sky glow' lighting pollution. Effective lighting also projects a minimal of light outwards. Outward shining light creates glare, a potential visibility hazard for motorists, cyclists and pedestrians. Furthermore, effective lighting is mostly projected downwards to provide the visibility level required for safety, security and recreation. Hence Figure 1(a) depicts an extremely undesirable projection of light from an outdoor luminaire. The light projection shown in Figure 1(b) is also very undesirable. The light projection from the luminaire in Figure 1(c) is better, but the projection of light shown in Figure 1(d) is the best of the four depictions. [0051] Figure 2 illustrates light pollution (or 'spill light) effects from a street light luminaire. Specifically it indicates the area beneath the luminaire that is intended to be lit (2), the direction of glare (4) experience by a pedestrian, the spill light zone (6) and the light trespass (8) that would be experienced through windows in an adjacent building. [0052] Light pollution is created by the combined effects of glare (4), light trespass (8) and sky glow. When the available light from a luminaire is not directed to where it is needed most, there is the potential to actually reduce the safety and security in the area 14 supposed to be illuminated. Glare is the visual distraction and discomfort experienced as a result of poor installation or inadequate light regulation. A person's ability to see details not directly illuminated is hindered. They should be able to see a hazard and not the light source. Light trespass is light that intrudes on a property, creating privacy issues and nuisance by shining into windows and other areas. Sky glow is created by light projected vertically by poor luminaire design, installation, or reflected light. It impacts habitat and behaviour of nocturnal animals and birds, and it symbolises energy wastage. [0053] Figure 3(a) is an exploded view of a preferred embodiment of a luminaire of the type suitable for use with the present invention and illustrates the major components. This view clearly shows the casing of the luminaire comprising a main body (1) of cast metal such as aluminium, or alternatively of polymeric material. The main body (1) includes a port (3) for receiving a hollow support (5) which would typically be located at the top of a pole and/or would form part of a bracket or similar structure. The port is adapted to receive a grommet (not shown) which may act as a seal between the support (5) and the port (3). A mains cable (not shown) would ordinarily be located within the support (5). [0054] The visor (7) is of unitary construction and at least in the vicinity of the lamp it is conformed to act as a prismatic lens. The visor is typically made of acrylic, polycarbonate or other hard wearing polymer that can be made clear or translucent, however, other suitable materials may used as would be understood by the person skilled in the art. The components located within the termination chamber (13) as well as the components of the reflector assembly (11) are visible through the visor (7). [0055] The main body (1) and visor (7) are held together by two clips (9a, 9b) and two integral hinges (10a, 1Ob not shown) located in corresponding positions on the other side of the main body and visor, thus permitting movement of the visor (7) from a first, closed position to a second, open position permitting full access to the reflector assembly (11) and termination chamber (13). [0056] Typically the main body (1) is removably connected to the support (5) by a pair of fasteners (15).

15 [0057] Figure 3(b) is a further exploded view of the lighting assembly of Figure 3a illustrating the components in greater detail. Again, this view clearly shows the casing of the lighting assembly comprising a main body (1) and a visor (7) and the two clips (9a, 9b) for holding the main body (1) and visor (7) closed. A gasket (10) of silicon, neoprene or any other suitable material assists in providing hermetic closure of the casing. [0058] In this view the components of the reflector assembly (11) can be more readily seen. These include a gear tray (17) having lamp holders (19a, 19b) for securing either ends of the lamps (21a, 21b), a reflector tray (23), an electronic ballast (25), a 3-way terminal socket (27) with two MOVs connected to supply terminals and a lanyard (29). An electronic ballast (also known as control gear) is a solid state electronic device that limits the amount of current in an electronic circuit particularly when the load does not regulate its own current consumption well enough. [0059] In the embodiment illustrated in this drawing the reflector assembly is adapted to support the electronic ballast and two lamps, preferably two 14 watt lamps which are equivalent to an 80 watt mercury vapour lamp but with 66% less energy use and reduced greenhouse emissions. However, the reflector assembly (11) may alternatively be adapted to receive a single or compact lamp. The reflector assembly (11) is held at one end to the main body (1), and at the other end to the termination chamber (13) by two pairs of fasteners (31 a, 31 b). A quick release lanyard (29) and plug socket are installed to assist component replacement. [0060] The termination chamber (13) includes a terminal tray (33), a terminal block (35) of plastic or other suitable material and is adapted to hold a PE cell (37). The PE cell (37) is seated in the terminal tray (35) and can be completely enclosed within the casing. The part of the visor (7) in the vicinity of the PE cell (37) is clear so that the PE cell (37) correctly detects the level of ambient light. Using frosting in other parts of the visor (7) however may provide the advantage of preventing reflected or early ambient light impinging on the PE cell (37) and causing it to prematurely deactivate. The main body (1) is fastened to the support (5) by a pair of large gauge fixing bolts and corresponding nuts (15a, 15b).

16 [0061] Figure 3(c)(i) illustrates the fully assembled lighting assembly of Figure 3(a) when viewed from underneath. This is the view that a person would have if they walked underneath the lighting assembly and looked up. In this view they would see through the visor (7) to the reflector tray (23) and lamps and the PE cell (37). [0062] Figure 3(c)(ii) illustrates the lighting assembly of Figure 3(c)(i) viewed in cross section along AA'. In this view the support (5) can be seen projecting into the elongated port (3) in the termination chamber (13). The main body (1) is fastened to the support (5) by a pair of large gauge fixing bolts (15). [0063] Figure 3(c)(iii) illustrates the lighting assembly of Figure 3(c)(i) viewed from the side. [0064] Figure 4 illustrates one embodiment of a device according to the present invention for controlling light spill from the left side or right side of a luminaire. Various embodiments of the light spill control device of the present invention can be provided, including various shapes and formats that fit inside the visor of the luminaire and alter the spread or shape of the light, ensuring that the light is directed to where it is intended, minimising light pollution. Thus, the light spill control device of the present invention can be provided, for example as (i) aeroscreen (ensuring effective light is concentrated downward and not spread right or left), (ii) transverse cut-off (limiting the front and/or rear light concentration), (iii) left side cut-off (concentrating light on the right hand side of the luminaire), or (iv) right side cut-off (concentrating light on the left hand side). [0065] Aeroscreen devices can provide directional and concentrated light on a specific area (not spread right and left) and avoiding glare in applications such as pedestrian crossing points, streets, identified hazards such as speed humps, traffic islands, sharp curves or car parks near airports. Transverse cut-off devices reduce the front and/or rear light levels, whilst maintaining the available light directed to each side of the luminaire. This could be employed for example on narrow roads, laneways or where light trespass illuminates a private residence. Left and right hand cut-off devices limit the spread of light to one side only, thus minimising unwanted light on a particular side where it might create issues or is unnecessary.

17 [0066] In the perspective view of the device in Figure 4(a) can be seen the support surface (50) which in use is attached to the visor (7) of a luminaire, enclosed within the main body (1) and the visor (7). The support surface (50) includes holes (56a, 56b) which can be located on existing lens pins by push-on spring clips. One edge of the support surface (50) is angled (at 300) as shown in the cross sectional view of Figure 4(b), and integral with an elongate baffle (52). [0067] In this configuration, the light spill control device can be retrofitted to existing street lights, avoiding the need to replace the luminaire if it is discovered after installation of the luminaire that it causes light pollution problems. [0068] The device can be pressed from a single elongate strip of metal, typically mild steel which is finished by preferably dark coloured powder coating. [0069] When located within the luminaire as shown in Figure 4(c), the baffle (52) controls the light from the fluorescent lamps (21 a, 21 b) which would otherwise spill to the left of the luminaire. Alternatively the baffle (52) could be associated with the lens pins on the other, parallel side of the visor (7) to control the light which would otherwise spill to the right of the luminaire. In another alternative, two devices can be associated with either side of the visor (7), controlling light which would otherwise spill to the right and the left of the luminaire, thus effectively also controlling light directed downwards. [0070] Figure 5 illustrates one embodiment of a device according to the present invention for controlling light spill from the front, back or directly downwards from a luminaire. The perspective view of Figure 5(a) the device has two elongate, parallel support surfaces (61,62) associated with multiple baffles (65) located transverse to the support surfaces (61,62). Depending on the angle and orientation of the baffles relative to the support surfaces, the device can be configured to control light spill to the front, back or directly beneath the luminaire. [0071] Figure 5(b) is an end view of the device of Figure 5a, and clearly illustrates the 300 angle of the support surfaces (61, 62) relative to the baffles (65). Figure 5(c) shows the device viewed from above and in this view can be seen the holes (67) which can be used to attach the device to the visor (7) of a luminaire.

18 [0072] Figure 5(d) shows the device located within the luminaire of Fig. 1 such that it controls the spill of light to the front, back or directly downwards from a luminaire. In another configuration, a device as shown in Figure 4 could additionally be included in the luminaire. [0073] The device of Figure 5 can be pressed from a single elongate strip of metal. For example the shape could readily be cut from a flat (0.5mm) sheet of mild steel or (0.5mm) sheet of semi-specular reflector aluminium. The baffles could be produced by twisting sections of the sheet by 900. The device could then be finished by powder coating, or black anodising. [0074] Figure 6 illustrates isolux diagrams for a luminaire (known as an Enviro T5 Standard from Streetworx Pty Ltd) with and without spill control devices according to the present invention. [0075] Figures 6(a) and 6(b) are respectively, a polar diagram and an isolux diagram for the Enviro T5 luminaire without any spill control. [0076] Figures 6(c) and 6(d) are isolux diagrams for the Enviro T5 luminaire fitted with a spill control device of the type shown in Figure 5, configured to control transverse light spill (Fig.6(c)) and configured to act as an aeroscreen spill control device (Fig.6(d)). [0077] Figures 6(e) and 6(f) are isolux diagrams for the Enviro T5 luminaire fitted with a spill control device of the type shown in Figure 4, configured as a left side longitudinal spill control device (Fig.6(e)) and a right side longitudinal spill control device (Fig.6(f)). [0078] Figure 7 illustrates the typical light spread of three standard street light luminaire (Fig.7(a)) across a road (70) and a property line (75) compared with the light spread when two of the luminaires (80) are fitted with a device of the present invention configured for transverse cut-off, and the third luminaire (85) is fitted with a device configured for left hand cut-off.

19 [0079] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth. [0080] As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. The described embodiments are to be considered in all respects as illustrative only and not restrictive. [0081] Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. In the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural equivalents, but also equivalent structures [0082] "Comprises/comprising" and "includes/including" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', 'includes', 'including' and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Claims (18)

1. A light spill control device comprising: - a support surface for associating the device with the visor of a luminaire, and - at least one baffle associated with the support surface, wherein the at least one baffle is at least partially enclosed by the visor of the luminaire.

2. A device according to claim 1 wherein the support surface has an elongate edge associated with an elongate baffle and can be located within the visor of the luminaire to control light spill to the left or right of the luminaire.

3. A device according to claim 1 wherein the support surface is adapted to rest on an internal surface of the visor.

4. A device according to claim 1 wherein the light spill control device is integral with the visor.

5. A device according to claim 1 wherein the device has two elongate support surfaces associated with either ends of two or more baffles located transverse to the support surfaces for controlling light spill to the front, back or directly beneath the luminaire.

6. A device according to claim 1 wherein the baffles and/or support surfaces are of dark colour.

7. A device according to claim 1 configured for aeroscreen cut-off of light from a luminaire.

8. A device according to claim 1 configured for transverse cut-off of light from a luminaire. 21

9. A device according to claim 1 configured for left or right side cut-off of light from a luminaire.

10. A lighting assembly having: - a casing comprising a main body defining a port for receiving a mains cable, - a visor, - a reflector assembly for receiving at least one lamp, - a termination chamber, and - a light spill control device, wherein the light spill control device includes a support surface associated with the visor and at least one baffle associated with the support surface, wherein the at least one baffle is at least partially enclosed by the visor.

11. A lighting assembly according to claim 10 wherein the light spill control device is located intermediate the reflector assembly and the visor, and solely in contact with the visor.

12. A lighting assembly according to claim 10 which further includes at least one lamp chosen from T5, T8 or T12 fluorescent lamps.

13. A lighting assembly according to claim 10 wherein the casing is elongate and adapted for external use.

14. A system for control of light spill from a luminaire, the system comprising at least one device according to claim 1 associated with, and at least partially enclosed within the visor of a luminaire. 22

15. A method of manufacturing a light spill control device of the present invention including the steps of: - cutting a sheet of material to define at least one support surface - providing at least one transverse baffle, with an edge attached to the support surface, - twisting the at least one transverse baffle, and - forming attachment means in association with the at least one support surface.

16. A method as claimed in claim 15, wherein the at least one transverse baffle is provided in the cutting step.

17. A method of manufacture according to claim 15 wherein the transverse baffled is twisted in the range of 12 to 900.

18. A method of controlling a light spill in a luminaire including the step of installing the device of claim 1 in the visor of a luminaire.