AU2018250963A1

AU2018250963A1 - Improved lighting apparatus

Info

Publication number: AU2018250963A1
Application number: AU2018250963A
Authority: AU
Inventors: George Ossolinski
Original assignee: LUNAR LIGHTING Pty Ltd
Current assignee: LUNAR LIGHTING Pty Ltd
Priority date: 2017-04-10
Filing date: 2018-02-27
Publication date: 2019-11-28
Also published as: WO2018187833A1; EP3610191A4; ZA201907433B; EP3610191A1

Abstract

A lighting array (26) comprising a plurality of elongate tubular lighting elements (10) each defining a first end and a second end. Each tubular lighting element (10) comprises an elongate housing containing a plurality of LEDs (25), the elongate housing including a light transmissive material on one side (12), and a heat sink (17) on an opposite side of the housing. The plurality of tubular elements (10) are arranged in an annular array with a first end of each of the tubular lighting elements being mounted to a first heat conductive plate (30), each tubular element being separated from adjacent elements in the annular array by a gap. The light transmissive material (12) of each tubular lighting element is arranged facing the exterior of the annular array and the heat sink (17) of each tubular lighting element faces the interior of the array and is connected to the plate (30).

Description

Improved lighting apparatus

Cross-Reference to Related Applications [0001] The present application claims priority from Australian Provisional Patent Application No 2017901307 filed on 10 April 2017, the content of which is incorporated herein by reference.

Technical Field [0002] This invention relates to an improved lighting apparatus which is typically a portable lighting system, but may be permanent. In particular it relates to a lighting apparatus, which can be used to provide a diffuse, glare free and uniform light over a wide area, and typically over a 360° arc.

Background [0003] There are a number of known ways to provide glare free light over a wide area. For example, it is known to provide a balloon comprising an inflatable envelope which is inflated with a gas such as air or helium, place a light source in the balloon and tether the balloon to the ground using an elongate element keeping the balloon at a certain height above the ground. Such balloons are used for the provision of a diffused light source which may for example be needed for outdoor filming, photography, civil works, construction, or for use by emergency services.

[0004] However lighting balloons are expensive (helium is expensive, as are the lighting envelopes, which need replacing regularly and the globes) and the labour required to rig the balloons is also expensive. Lighting balloons are also cumbersome and have a number of problems. First, inflatable balloon envelopes tend to deform quite readily when subject to relatively strong air currents because of the relatively low pressure setting and even the smallest holes in the envelope may cause the balloon’s safety circuit to cut power to the bulb. In more adverse conditions, illuminated balloons switch off more often and provide unsatisfactory lighting and the globes fail frequently.

WO 2018/187833

PCT/AU2018/050176 [0005] A further issue is that lighting balloons do not work at high altitudes or in very cold climates as the lighting envelope can very easily become deformed due to the low air density, resulting in the safety circuit being activated which cuts the power supply and switches off the light.

[0006] There is a further problem with existing inflatable balloon systems and that is their slow inflation rate and noisy operation which is a particular problem when filming. Being unstable, lighting balloons need to be secured to “Cherry Pickers” to keep them in one position and not sway from side to side, especially during film productions where the lumen output needs to be constant.

[0007] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.

Summary [0008] According to the present invention there is provided a lighting array comprising a plurality of elongate tubular lighting elements, the elements being arranged in an annular array with one end of each of the tubular lighting elements being mounted to a plate, preferably a circular annular ring or perforated plate formed from a heat conductive material, each tubular element being separated from adjacent elements in the annular array and each tubular element comprising a plurality of LEDs located between a light transmissive material typically a diffuser, and a heat sink wherein the diffuser is arranged facing the exterior of the array and the heat sink faces the interior of the array and is connected to the plate.

[0009] More specifically there is provided a lighting array comprising a plurality of elongate tubular lighting elements defining a first end and a second end, wherein each tubular lighting element comprises an elongate housing containing a plurality of LEDs, the elongate housing including a light transmissive material on one side, and a heat sink on an opposite side of the housing; and wherein

WO 2018/187833

PCT/AU2018/050176 the plurality of tubular elements are arranged in an annular array with a first end of each of the tubular lighting elements being mounted to a first heat conductive plate, each tubular element being separated from adjacent elements in the annular array by a gap wherein the light transmissive material of each tubular lighting element is arranged facing the exterior of the annular array and the heat sink of each tubular lighting element faces the interior of the array and is connected to the plate.

[0010] By arranging the tubular lighting elements in an annular array, natural convection of air can be used to cool the LEDs and no noisy fan is required, although for applications where noise is not an issue, a fan could be provided to encourage air flow. Air flows up through the unit passing the fins of the heat sink and convecting heat up through the top of the array. Heat can also be release through the small spacings between the tubes.

[0011] Typically the lighting array will have an associated control unit which supplies electrical power to the tubular elements. It is preferred that the tubular elements are electrically connected together in arcuate sections which can be individually switched ON or OFF. Hence for a 360° annulus five sections each of 72° may be provided. The size and number of sections may be varied, particularly if the wattage of the array increases. A dimmer switch will preferably be provided for adjusting the brightness of the array.

[0012] Typically the array will have about forty five tubular elements depending on the size and power required. Larger arrays including more tubes are possible, as are smaller arrays.

[0013] In one embodiment, the array comprises mixture of elements providing visible light and infra-red light, most typically alternating one after the other. Of course other colours, colour temperatures and combinations of the same are possible. For example LEDs providing sodium light spectrum could be provided.

[0014] Throughout this specification the word comprise, or variations such as comprises or comprising, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

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PCT/AU2018/050176

Brief Description of Drawings [0015] Specific embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings in which: Figure 1 shows an extrusion and diffuser which form part of a tubular lighting element;

Figure 2 is a side elevation of a lighting array embodying the present invention including a plurality of tubular lighting elements;

Figure 2a is a schematic drawing illustrating a strip of LEDs:

Figure 3 is a top plan view of the lighting array of Figure 2, showing hidden detail in phantom dashed lines;

Figure 4 is an underneath plan view of the lighting array of Figure 2 showing hidden detail in phantom dashed lines;

Figure 5 is a schematic drawing of the lighting array, including a control unit; and

Figure 6 is a photographic view of a lighting tower.

Description of Embodiments [0016] Referring to the drawings, Figure 1 illustrates the housing of a tubular lighting element or lighting tube 10. The housing comprises an elongate diffuser element 12 made of polycarbonate or a similar material (such as another polymer) having a semi-circular crosssection. The length of the element is not critical but in the described embodiment, the length is 560mm. The ends of the cross-section define radial internal flanges 14, 16.

[0017] The housing also includes an elongate heat sink 17 preferably made of Aluminium 6061 T6 due to its high heat conductivity. The heat sink 17 defines a rectangular section 18 which defines slots 20, 22 which receive the radial flanges of the diffuser. A series of fins 24 whose ends terminate in a semicircle of the approximately same radius as the diffuser element

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PCT/AU2018/050176 project from the rectangular section 18. The axes of the fins are parallel to the longitudinal axis of the lighting element.

[0018] Inside the housing, not shown in Figure 1, but shown in Figure 2a, are a series of electrically connected LEDs which are mounted in the rectangular section 18. Each tube will typically include about 36 LEDs. However if a higher wattage output is required, the number of LEDs will be increased. The LEDs are electrically connected to each other. Typically the LEDs are connected in parallel however they could be connected in series or in a combination of series and parallel.

[0019] Figure 2a is a schematic drawing showing a part of one strip of LEDs 25 which are mounted on a rectangular strip of aluminium 27, with connecting wires for attachment to electrical power. The aluminium strip 27 is mounted in contact with the heat sink 17 to maximise heat transfer from the LED strip.

[0020] Turning now to Figures 2 to 4, these Figures show a lighting unit/array 26 including a plurality of tubular lighting elements 10 (45 in total). The housing is cylindrical and the diameter of the housing is typically about 430mm. As is best seen in Figure 4, the elements are arranged in an annular (circular) array mounted between a lower plate 30 and an upper plate 32, extending vertically upwards with one lower end of each lighting element located on the circumference of the circle. Both plates are made of high grade aluminium for optimum heat conduction. It will be appreciated however that while the preferred arrangement is circular other non-circular annular arrangements/sections are possible such as a pentagonal or hexagonal section. A circular array however provides the best and most even overall light coverage. The tubes 10 are preferably separated by a small gap typically of the order of 2 to 4 mm to allow cooling air to flow between the tubes.

[0021] With reference to Figure 2, the lower plate 30/base of the lighting unit defines a connector/socket 40 for receiving a tripod. The base also defines a series of ventilation slots 42 to allow the passage of air upwards through the base of the lighting unit. It is envisaged that in a variation additional slots may be provided in the base to increase airflow. In a further variation, not shown, the base could be substantially open and the plate 30 could be a simple planar annular ring.

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PCT/AU2018/050176 [0022] The adjacent tubular lighting elements are electrically connected in five sections/segments of nine tubes. Each section/segment subtends an angle of 72° In the described embodiment the base also defines five plugs 44 for electrical connections, one for each of the five sections. However it is envisaged that instead of five separate wires and plugs, a five way connector with a spiral cable could be used instead.

[0023] Although it is shown closed in drawings, the top plate 32 should preferably either be substantially open or should define a series of slots or perforations similar to the lower plate, to allow the flow of air through the unit. Hence in one embodiment the same plate 30 can be used for both top and bottom plates. In a preferred embodiment the top plate defines a loop or connection (not shown) by means of which the unit can be hung, typically an eye bolt placed in the centre of the top plate 32. The top plate will also include a five way connector for connecting with the spiral cable. If the wattage increases the array may include more than 5 segments and the connector will accept additional cables.

[0024] Figure 5 shows a schematic drawing of a lighting unit 26 including a tripod 60 and a control/power unit 70. The lighting unit includes a loop 62 for hanging the lighting unit, in the event that it is not tripod mounted. The control unit includes a series of switches 72, 74, 76, 78, 80 for switching on each of the five segments of the unit and a dimmer switch 82 for dimming the LED lights. The control unit can plug into mains electricity of to an electrical generator or the like.

[0025] Lighting arrays embodying the present invention have a number of significant advantages over the prior art. By using LEDs they are able to provide up to 210 lumen per watt (23 lOLm/W), which is more than double the lumen per watt output of HMI lighting which is typically lOOlm/W and provide a substantially glare free uniform lighting output with a high lumen output. The LED’s are also covered with a waterproofing compound such as polyurethane which enables them to be used in outdoor environments.

[0026] Figure 5 illustrates a control unit for the lighting array. While the specific components used for the control unit are not critical and may be varied a number of features are preferred.

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PCT/AU2018/050176 [0027] First, the adjacent tubular lighting elements are connected in five sections/segments of nine tubes. Each section/segment subtends an angle of 72° For a 1650W lighting array, each segment may be switched ON or OFF independently of the other sections. Thus the lighting array may provide 33OW, 660W, 990W, 1320W or 1550W depending on how many of the five sections are lit. The control unit also includes a dimmer control to dim the lighting array.

[0028] Typically, the unit will draw about 6.8 Amps when delivering 1650 W dropping to 1.3 Amp when 33OW is supplied. While the colour temperature of the lighting elements may be varied, a daylight colour temperature of 6000K with a colour rendering index of 95 is one preferred option.

[0029] The control unit may be designed to operate at anything from 90V to 260V AC current to cope with the power supply in different countries.

[0030] The life and operating conditions of the LEDs may be varied however in the described embodiment, the LEDs are rated for 50,000 hours and are able to operate between 40°C and 85°C.

[0031] The lighting array is relatively lightweight at approximately 14Kg, and can be mounted on top of a tripod (not shown), or a lighting tower or simply suspended from an eyebolt hook (not shown) fixed to centre of the top of the lighting array top plate.

[0032] The lighting array may also be provided in the format of a lighting tower, mounted on top of a trailer 100 carrying a generator as shown in Figure 6. In this embodiment, the lighting array 26 will be mounted on top of a telescopic pole 102 which can be extended to raise the position of the lighting array.

[0033] In one embodiment the lighting unit includes LED lighting tubes which provide infra-red light rather than visible light. The unit may include both visible and infra-red lighting tubes. Visible and infra-red lighting tubes may be arranged alternately and may be operated separately so that the unit can provide only infra-red light or only visible light or both, and even combinations such as visible, infra-red and sodium vapour.

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PCT/AU2018/050176 [0034] Advantageously the lighting unit is reliable, relatively inexpensive and can work in temperatures from -40°C to 85°C and withstand extreme winds, hence addressing issues with lighting balloons.

[0035] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A lighting array comprise a plurality of elongate tubular lighting elements defining a first end and a second end, wherein each tubular lighting element comprises an elongate housing containing a plurality of LEDs, the elongate housing including a light transmissive material on one side, and a heat sink on an opposite side of the housing; and wherein the plurality of tubular elements are arranged in an annular array with a first end of each of the tubular lighting elements being mounted to a first heat conductive plate, each tubular element being separated from adjacent elements in the annular array by a gap wherein the light transmissive material of each tubular lighting element is arranged facing the exterior of the annular array and the heat sink of each tubular lighting element faces the interior of the array and is connected to the plate.
2. A lighting array as claimed in claim 1 wherein the first heat conductive plate is a circular annular ring.
3. A lighting array as claimed in claim 1 wherein the first heat conductive plate is a perforated plate formed from a heat conductive material.
4. A lighting array as claimed in any one of claims 1 to 3 wherein the light transmissive material is a diffuser formed from polycarbonate.
5. A lighting array as claimed in claim 4 wherein the diffuser has a part circular crosssection, typically semi-circular.
6. A lighting array as claimed in any preceding claim wherein the heat sink is formed from aluminium and defines a series of fins for dissipating heat generated by the LEDs.
7. A lighting array as claimed in any preceding claim wherein some of the tubular elements in the array include LEDs which emit infra-red light.