FIELD

The field relates to a lighting assembly for use in, but not being limited to, navigation beacons.

BACKGROUND A navigation beacon is a device that can generate signals (e.g. by radio or visible light) for alerting navigators to the presence of (or their position relative to) a nearby hazard or landmark, such as for guiding a vessel or aircraft.

Most existing navigation beacons use a single incandescent light source, which can consume a significant amount of electrical power and require frequent replacement as the filament in such light sources have a relatively short lifespan when put to constant use. Figure 1 is a diagram of a typical navigation beacon 100 using a single incandescent light source 102. The navigation beacon 100 has a green light filter 104 and a red light filter 106. Light beams produced by the source 102 travel in a straight line and passes through the filters 104 and 106. As a result, an observer will see either a red light (at position A) or a green light (at position B) depending on the observer's position relative to the beacon 100. When the observer moves from position A to position B, the observer will see a red light suddenly changing to a green light.

Light emitting diodes (LEDs) are increasingly being used as a replacement for incandescent light sources, such as in traffic lights. LEDs offer several advantages, including the ability to produce the same luminosity as incandescent light sources but using less power, and which also have a longer effective working life (thus minimising the need for regular replacement).

However, LEDs are typically manufactured with the light producing element encased within a transparent (or translucent) body that includes a lens portion shaped for spreading light over a wide area. The lens portion makes it very difficult to control the direction of light being produced by an LED (particularly in a vertical direction). This presents a significant problem if LEDs are used as a light source for navigation guidance purposes. To illustrate the problem, Figure 2 shows an example of a navigation beacon 200 having two sets of LEDs 202 and 204. A first set 202 produces green light and a second set 204 produces red light. Since the light from each LED spreads over a wide area, a user at positions A, B and C will be able to see different proportions of red and green light. A beacon of the type shown in Figure 2 can confuse navigators (or observers) since it is not possible to clearly see a different colour of light from the beacon depending on the position of the observer relative to the beacon. This presents a significant barrier to the use LEDs in navigation beacons, since different coloured light from such beacons are used to indicate whether an observer's position (relative to the beacon) is safe or hazardous.

It is therefore desired to address one or more of the above problems, or to at least provide a useful alternative.

SUMMARY In a described embodiment, there is provided a lighting assembly, including: a base supporting a row of one or more light emitting elements in an outward facing configuration for emitting light away from said base; and one or more optical elements, each corresponding to a different said light emitting element, wherein each said optical element enables light from a corresponding said light emitting element to pass through a first portion and then a second portion of the optical element, said first portion being adapted for controlling a spread of said light substantially along a first axis, and said second portion being adapted for controlling a spread of said light substantially along a different second axis.

BRIEF DESCRIPTION OF THE DRAWINGS Representative embodiments of the present invention are herein described, by way of example only, with reference to the accompanying drawings, wherein:

Figure 1 is a diagram of a typical navigation light beacon;

Figure 2 is a diagram of an exemplary light beacon using LEDs;

Figure 3 is an exploded perspective view of the lighting assembly; Figure 4 is a bottom perspective view of a lens member of the lighting assembly;

Figure 5 is a top view of the lighting assembly when assembled;

Figure 6 is a sectional view of the lighting assembly along section A- A of Figure 5; Figure 7 is a sectional view of the lens member along section B-B of Figure 6;

Figure 8 is a top view of the base of the lighting assembly;

Figure 9 is a side view of the base of the lighting assembly;

Figure 10 is a sectional view of the base along section C-C of Figure 9; and Figures 11, 12, and 13 are respectively top, side and front views of an optical element of the lighting assembly;

Figure 14 is a diagram of the lighting assembly in one mode of operation;

Figure 15 is a diagram of the lighting assembly in another mode of operation; and

Figure 16 is another exploded perspective view of the lighting assembly. DETAILED DESCRIPTION OF THE REPRESENTATIVE EMBODIMENTS

A lighting assembly 300, as shown in Figure 3, includes a base 302, one or more optical elements 303 (which may be formed as part of a lens member 304), and one or more light emitting elements 306 (not shown in Figure 3).

A light emitting element 306 refers to any component (or a combination of components) capable of producing visible light (see Figure 15). A light emitting element 306 may include a light emitting diode (LED) of the type that can produce either a single colour or several different colours (e.g. depending on the voltage supplied to each LED). A light emitting element 306 may also include a support member 308 (see Figure 15) adapted for coupling the light emitting element 306 to the base 302. The support member 308 may be a panel (or printed circuit board) having connections for providing power to a light emitting element, as well as any components for controlling the operation of the light emitting element 306. Each light emitting elements 306 may be powered by electricity from mains, a battery or a solar power source (e.g. one or more solar cells coupled to the lighting assembly 300). The base 302 is adapted to support the one or more light emitting elements 306. In a representative embodiment, as shown in Figure 3, the base 302 includes a supporting surface 310 onto which one or more light emitting elements 306 can be attached (e.g. by an adhesive). The base 302 may also have one or more supporting arms 312 adapted for securing a light emitting element 306 in a fixed position relative to the base. For example, different portions of a light emitting element 306 may engage with (or be received into) one or more projections or recesses formed in different support arms 310 so as to securely hold the light emitting element 306 in an outward facing configuration for emitting light away from the base 302. In a representative embodiment, the light emitting elements 306 are positioned around an arcuate or peripheral portion of the base 302. However, it will be appreciated that the light emitting elements 306 can be coupled to different parts of the base 302.

The lens member 304 can be removably fitted over the base 302. In a representative embodiment, the lens member 304 has one or more optical elements 303 positioned around a peripheral portion of the lens member 304, such that when the lens member 304 is fitted over the base 302, each optical element 302 is positioned adjacent to a different light emitting element 306.

Figure 4 is a bottom perspective view of the lens member 304 as shown in Figure 3. The lower portion of the lens member 304 is formed to include one or more locking recesses

400 for receiving a corresponding locking tab 402 formed in a lower portion of the base

302. In other representative embodiments, the locking recesses 400 may instead be formed on the base 302, and the locking tabs 402 may instead by formed on the lens member 304.

When the lens member 304 is fitted over the base 302, the locking tabs 402 are received into the locking recesses 400 so as to resist rotation of the lens member 304 relative to the base 302. This enables the optical elements 303 to remain substantially aligned and adjacent with the corresponding light emitting elements 306.

Each optical element 303 is adapted to control a spread of light emitted from a different corresponding light emitting element 306. Figures 11, 12 and 13 respectively show a top view, side view and a front view of a representative embodiment of an optical element 303. The optical element 303 enables light from a corresponding light emitting element 306 (positioned to the left of the optical element 303 shown in Figure 11) to pass through a first lens portion 1100 and then a second lens portion 1102. The first lens portion 1100 is adapted or shaped for controlling a spread of light substantially along a first axis 1300. The second lens portion 1102 is adapted or shaped for controlling a spread of light substantially along a second axis 1302 that is different to the first axis 1300. In a representative embodiment, the first and second axes 1300 and 1302 are perpendicular with respect to each other. As shown in Figures 1 and 13, the first axis 1300 and second axis 1302 may be substantially horizontal and vertical respectively relative to the optical element 303 (and/or base 302). The first lens portion 1100 is adapted for converging light from the light emitting element 306 substantially along the first axis 1300. Similarly, the second lens portion 1102 is adapted for converging light from the light emitting element 306 substantially along the second axis 1302. In a representative embodiment, this is achieved by having the first lens portion 1100 adapted to provide a first convex surface 1104 (which faces the light emitting element 306) with a substantially consistent cross-section extending along a first linear axis 1108 perpendicular to the first axis 1300. In Figure 11, the first linear axis 1108 extends into the page. Similarly, the second lens portion 1102 is adapted to provide a second convex surface 1106 (which faces away from the light emitting element 306) with has a substantially consistent cross-section extending along a second linear axis 1200 perpendicular to the second axis 1302. In Figure 12, the second linear axis 1200 extends into the page.

As shown in Figure 13, the second convex surface 1106 can be advantageously shaped so that a centre portion 1304 of the surface 1106 has a smaller cross-sectional width relative to that for the end portions of the surface 1106. This increases the curvature of the second convex surface 1106 around the centre portion 1304 relative to the curvature around the end portions, which increases the corrective power around the centre portion 1304 for converging light along the second axis 1302 (relative to that for the end portions). It should be noted that the second convex surface 1106 for each optical element 303 should be arcuate (see Figure 11) in order to provide a circular outer surface for the lens member 304. In this configuration, the end portions of second convex surface 1106 will be positioned further away from the light emitting element 306 than the centre portion 1304. Therefore, by adapting centre portion 1304 and end portions of the second convex surface 1106 to have different corrective power (depending on their relative distance from the light emitting element 306) it is possible to provide a more even convergence of light from the light emitting element 306 along the second axis 1302.

Figures 14 and 15 illustrate two representative embodiments of the lighting assembly 300 that are configured for different applications. In Figure 14, the lighting assembly 300 has four different light emitting elements 1400, 1402, 1404 and 1406 arranged in an arcuate configuration. The light from each light emitting element 1400, 1402, 1404 and 1406 passes through a corresponding optical element 303 (formed in the lens member 304) for converging the light in the manner as described above. It can be seen from Figure 14 that there is a degree of overlap (e.g. 22°) in the light emitted by adjacent light emitting elements 1400, 1402, 1404 and 1406. For example, the light from light emitting elements 1404 and 1406 may be controlled by the corresponding optical elements 303 to spread over different sectors 1408 and 1410 of the same size (in degrees). This configuration does not present problems where the light emitting elements 1400, 1402, 1404 and 1406 all emit the same colour, but is undesirable where the light emitting elements emit different colours (as described in Figure 2).

In Figure 15, the lighting assembly 300 includes a plurality of light emitting elements 1500, 1502, 1504 and 1506 organised into one or more different subsets, each subset having one or more different light emitting elements 1500, 1502, 1504 and 1506, and the light emitting elements 1500, 1502, 1504 and 1506 in each subset being adapted for producing light of a different colour. In the representative embodiment shown in Figure 15, light emitting elements 1500, 1502 and 1504 each belong to a different subset, and each generates a different colour.

The light produced by the light emitting element 1500 passes through the corresponding optical element 303 (formed in the lens member 304) which covers a first sector 1508. The light produced by the adjacent light emitting element 1502 is controlled to cover a smaller sector 1510 in order to minimise overlap with the light in the adjacent sector 1508. This may be achieved by providing a barrier portion adjacent to the corresponding light emitting element 1502, which has optically opaque portions for defining an optical opening for limiting a spread of light from the light emitting element 1502 along at least one of the first axis 1300 and the second axis 1302. The barrier portion may be part of a barrier member 1514 that is supported by the base 302 in a position between a light emitting element 306 and its corresponding optical element 303. Alternatively, the barrier portion may refer to certain portions of the first convex surface 1104 that are adapted to be optically opaque (e.g. painting portions of the surface 1104 with an optically opaque paint) so as to define an optical opening. The light produced by the light emitting element 1504 is also controlled by a barrier portion (or barrier member 1516). The size of the optical opening defined by the barrier portion can be adapted in size to control the sector region over which light from a light emitting element 303 can spread. In a representative embodiment, different barrier members can be produced (each defining different sized optical openings) which can be selected for use with the lighting assembly 300 depending on the sector characteristics required for different light emitting elements 303 (e.g. of different colour). This provides a quick and easy way for producing the light assembly 300 to meet the specific light colour and sector specifications relevant to, for example, marine and aviation navigation requirements.

The optical output produced by each light emitting element 306 may be controlled by a corresponding driver module 314 (not shown in the Figures). Each light emitting element 306 may operate on a range of different voltage levels, which determines (or is determined by) the colour of light produced by each light emitting element 306. For example, the colours green, white and blue are typically produced by a unique voltage within a range of 3 to 4.4 volts, and the colours red and yellow are typically produced by a unique voltage within a range of 2 to 2.5 volts. The driver module 314 may include components for storing configuration data such as flash codes, intensity settings, and other control settings for controlling the optical output of the corresponding light emitting element 306.

Each driver module 314 may respond to control data representing one or more signals, commands, parameters or instructions that are generated by a control module 316 (not shown in the Figures) by changing one or more configuration parameters (e.g. voltage, current, or a change in voltage and/or current over any period of time) to control the optical characteristics of the light produced by the corresponding light emitting element 306. For example, the configuration parameters may control optical characteristics including the (i) colour, (ii) intensity (or brightness), or (iii) changes in colour and/or brightness over a period of time.

The driver module 314 and the control module 316 may each be provided by computer program code for controlling the operations performed by either one or several different processors (such as a microprocessor or other instructable processing unit). In a representative embodiment, driver module 314 and control module 316 controls separate processors that work together for controlling the light output produced by the light emitting elements 306 of the lighting assembly 300. Those skilled in the art will appreciate that the processes performed by the driver module 314 and control module 316 can also be executed at least in part by dedicated hardware circuits, e.g. Application Specific Integrated Circuits (ASICs) or Field-Programmable Gate Arrays (FPGAs). It may also be appreciated that the driver module 314 and control module 316 may be combined in future miniaturization of electronic components. In another representative embodiment, the control data generated by the control module 316 may be used (e.g. by a processor) to control different sets of one or more light emitting elements 306 of the lighting assembly 300. Each set may include one or more light emitting elements 306. The light emitting elements 306 in a particular set may be positioned adjacent to each other when attached to the base 302, or alternatively, in any other configuration. In this embodiment, the light emitting elements 306 in the same set respond to the control data generated by the control module 316 in the same way.

The ability to control each individual light emitting element 306 (or a set of multiple light emitting elements 306) using the driver module 314 and/or the control module 316 can provide several advantageous features. For example, it is possible to turn on the light emitting elements 306 (e.g. those facing towards the open sea or other relevant signalling area), while leaving the remaining light emitting elements 306 (e.g. those facing towards land) in an power off state to conserve power consumed by the lighting assembly 300. It is also possible to control the colour and intensity of the light emitting elements 306 to achieve compliance to aviation requirements, such as unidirectional and bidirectional runway lights under international standards (such as those by the FAA and ICAO). By having the ability to sector light output, and control the power levels to an individual or group of light emitting elements 306, the lighting assembly 300 can achieve the requirements for elevated lights where a combination of colours (e.g. red/green and yellow/white) are required to be produced by a single lighting assembly. For example, a lighting specification may require a lighting assembly to produce 180 degrees red and 180 degrees green. Further, the specification may require that the green sector to be greater than 600 candela, but the red sector to be only greater than 20 candela. The lighting assembly 300 described herein is able to comply with such specifications by allowing independent control of the power levels to the light emitting elements 306 in each sector within the same lighting assembly 300.

It is also possible to control the colour produced by the light emitting elements 306 in different sectors of the lighting assembly 300, and the sectoring of light can be further controlled by using barrier portions (or barrier members 1514 and 1516) as described above. It is also possible to control the timing in which each light emitting element 306 changes from its lowest intensity to its highest intensity, and then vice versa, so that when adjacent light emitting elements 306 are controlled in this manner in sequence the light emitting elements 306 can produce the a lighting effect resembling a rotating light whilst the lighting assembly 300 remains stationary.

Each lighting assembly 300 may be controlled by a different respective control module 316, which may be fitted inside the housing of the lighting assembly 300. The control module 316 may also work with a communications module 318 (not shown in the Figures) that enables the control module 316 to communicate with a central control system 320 (not shown in the Figures) via any electronic communications means, such as by radio, satellite, via a wireless or mobile telecommunications network (e.g. GSM) or any other communications network (such as a local wired network). The central control system 320 may control the operation of each control module 316 by way of generating central control data representing one or more signals, commands, parameters or instructions. The central control system 320 may also generate central control data directed towards (and for controlling the operation of) different groups of lighting modules 300, where each group may include one or more lighting modules 300.

In yet another representative embodiment, the control module 316 may also work with a monitoring module 322 (not shown in the Figures) that enables the control module 316 to perform one or more monitoring functions. The parameters monitored by the monitoring module 322 may include one or more of the following: (i) wind speed and direction, (ii) a longitude and latitude position (e.g. by GPS), (iii) a level of surrounding light, (iv) wave height, (v) water turbidity, (vi) water salinity, (vii) compass bearing, and (viii) an angle at which the lighting module 300 is positioned (e.g. relative to a water level in the context of using the lighting assembly 300 in a buoy at sea). Wave height can be measured using one or more accelerometers that are sampled many times in a predefined time period. The sampled data represents changes in acceleration (or deceleration) during that time, from which it is possible to determine an estimate of the distance (or height) travelled during that time.

The communications module 316 can send the data detected by the monitoring module 322 back to the central control system 320 for analysis. This enables the lighting module 300 to also serve as a means for collecting useful data about the weather or other physical conditions around the lighting assembly 300, which can then be used to provide information to navigators (e.g. as a separate report, or by adjusting the lighting output characteristics of the light emitting elements 306 of the relevant lighting assemblies 300).

In this specification, including the background section, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or known to be relevant to an attempt to solve any problem with which this specification is concerned.

Modifications and improvements to the invention will be readily apparent to those skilled in the art. Such modifications and improvements are intended to be within the scope of this invention.