EP3224540B1

EP3224540B1 - Light fixture and module

Info

Publication number: EP3224540B1
Application number: EP15800937.3A
Authority: EP
Inventors: Gareth Evans
Original assignee: Lumishore Ltd
Current assignee: Lumishore Ltd
Priority date: 2014-11-24
Filing date: 2015-11-23
Publication date: 2019-05-01
Anticipated expiration: 2035-11-23
Also published as: EP3224540B8; WO2016083787A1; EP3224540A1; GB2536186A; GB201420857D0

Description

FIELD

The present invention relates to light fixtures and modules. Particularly, but not exclusively, the present invention relates to lighting fixtures for boats.

BACKGROUND

For large boats, often referred to as super-yachts, lighting is required on the side or underside to provide so-called underwater lighting. The lights on such boats are often mounted across the inner end of long metal tubes that are welded into the hull to form a porthole for the light to be emitted from the light into the water
Fixing the lights into the hull in this manner ensures that the light beam emitted by the lights is directed out of the hull and in parallel to the surface of the water. The tubes are welded into an aperture in the hull of the respective boat to ensure that the light is directed in parallel to the surface of the water and in parallel to each other in a manner which is independent of the hull curvature.
The longitudinal axis of the tube is parallel to the desired path for the light.
These tubes are machined from a single solid metal bar and can be prohibitively expensive to produce and heavy due to the materials used to make them and the size they need to be to provide appropriate structural integrity to the lighting fixture. The use of long tubes in the hull of a boat also obscures the light emitted by the light source inside the light as when the light is transmitted by the light source at least a portion of the light hits the walls of the tube which causes the light to be diverted in directions other than the intended direction.
The use of long tube also means that the thermal path between the light source and the external environment, that is the path travelled by the heat to the external environment after it has been emitted by the light source, is long and means that the heat management can be slow and cumbersome, partly due to localised heating of the water in the tube.
Aspects and embodiments were devised with the foregoing in mind.
US2014/218954 discloses a light fixture comprising a thermally conductive stepped formation comprising a plurality of steps and a plurality of light sources mounted to respective steps on the stepped formation.
WO98/33007 discloses a light fixture comprising a pair of divergent thermally conductive members each carrying a plurality of light sources. Each light source is adjustable through an angle and comprises a lens to focus the emitted light.

SUMMARY

A light fixture in accordance with an aspect may be used as part of a lighting module on a boat to provide underwater lighting in an underwater environment. A light fixture in accordance with the first aspect can reduce the loss of light in the underwater environment where maintaining a constant and reliable high level of lighting is important as the reliance on a long metal flange is removed. Removing the reliance on a long metal flange is also important as such flanges can generate pockets of turbulence in the marine environment surrounding a boat which means that the boat uses more fuel to move through the water. Light fixtures in accordance with the first aspect may be used on any vessel, particularly any vessel where underwater lighting is required.
A light fixture in accordance with the aspect may be mounted to a boat and adjusted in situ through an angle relative to the hull of the boat. The angle of adjustment may be in the range 0 to 60 degrees. This means that a light fixture according to the aspect can be fitted to a wide variety of boats. This also means that the light fixtures may be manufactured in larger quantities, thereby reducing the overall cost of manufacture, and fitted to many different varieties of boat afterwards.
In accordance with the present invention, there is provided a light fixture of the kind disclosed in US2014/218954 , which is characterised in that a plurality of lenses adjustable through an angle in the range 0 to 60 degrees are adapted to focus the light emitted from respective light sources, the light module having a thermally conductive mount adapted to mount the lighting fixture to a surface of a hull of a boat. The steps on the stepped formation may be in a first and/or a second axis, which may correspond to the horizontal and vertical axes relative to the surface of water or the deck of a boat.
The plurality of light sources may be a plurality of light emitting diodes (LEDs) that may be arranged as strips of discrete devices. The plurality of LEDs may also be arranged in matrix formation.
A light fixture in accordance with the aspect provides a plurality of light sources that can be individually illuminated to transmit light out of the light fixture without the light being lost within a long tube. Mounting each of the light sources to a thermally conductive step formation also provides a shorter thermal path to the external environment to direct the heat emitted from the light source away from the light source.
Mounting each of the plurality of steps to a respective step also allows control of the angle of the light beam to provide wider and more even beam spreads.
This solves the problem presented by lights in the prior art as the need for a long tube in which to mount the light is removed and the thermal path between the light source and the underwater environment is shortened.
The plurality of lenses may be a plurality or mixture of piano convex lenses, aspheric lenses, Fresnel lenses, total internal reflection (TIR) optical lenses, machined or coated reflector lenses or half ball lenses. Individually focussing each of the light sources provides a light fixture that can be adjusted according to the angle of the hull of a boat to optimise the light produced by the light fixture.
The thermally conductive stepped formation may comprise a high thermal conductivity material, such as copper or aluminium, to provide a high level of thermal conductivity to quickly conduct the heat emitted by the light sources away from the light sources and direct that light to an exterior environment such as the underwater environment which provides a natural cooling effect to the light fixture. By high thermal conductivity material, we mean a material with a thermal conductivity of at least 150 watts per meter Kelvin (W/mK).
The thermally conductive stepped formation may form a stepped printed circuit board (PCB) for the plurality of light sources or each of the steps on the thermally conductive stepped formation may form a PCB for the respective mounted light source.
The thermally conductive mount improves the thermal path between the light fixture and an external environment, such as the underwater environment.

DESCRIPTION

An embodiment will now be described by way of example only and with reference to the following single figure in which schematically illustrates a light fixture 100 in accordance with an embodiment of the present invention.
For the purposes of clarity, we describe the light fixture 100 in use on a boat 110 but this should not be understood to be limit the use of the light fixture to use on a boat 110.
We will now describe a light fixture 100 in accordance with the embodiment with reference to Figure 1. Light fixture 100 comprises a plurality of LEDs 102 a to d each respectively mounted to a PCB on a step 106 a to d on a copper stepped formation 104. The PCB provides driver electronics for the respective LED to which it is mounted. In another embodiment, the stepped formation 104 may form a stepped PCB for the respective LED.
The steps 106 a to d illustrated in Figure 1 are in the vertical axis. However, optionally or additionally, the steps 106 a to d may be stepped in the horizontal axis. Stepped formation 104 is mounted to the hull of boat 110 using a thermally conductive mount 108.
The hull of boat 110 comprises a transparent portion 112 through which light emitted by the LEDs 102 a to d can pass.
Light fixture 100 enables the LEDs 102 a to d to be much closer to the transparent portion 112 where the light enters the external environment. This reduces the amount of light that is obscured by the light fixture 100 or diverted off part of the light fixture 100 in a direction other than the direction intended. This means that more light is emitted from the light fixture 100 in the intended direction which makes the light fixture 100 more efficient.
An internally angled microlens 114 a to d is affixed over each of the LEDs 102 a to d to focus the light emitted by each of the LEDs 102 a to d. Each of the individual lenses 114 a to d may be oriented differently according to the angle of the hull of the boat and the direction in which the light needs to be propagated.
The effect of this is that each of the LEDs 102 a to d forms its own individually configurable optical system which can be configured to focus light emitted by each of the LEDs 102 a to d in a specific direction. This means that the light emitted by the LEDs 102 a to d can be directed through the transparent portion 112 and into the exterior environment which could well be underwater.
The use of a plurality of individually configurable optical systems in this way increase the flexibility of the light fixture 100 as the light emitted by the LEDs can be focussed in a direction that enables as much of the light as possible to travel out of the light fixture 100 and reduces the amount of light that is diverted by the other parts of the light fixture 100.
The angle of the stepped formation 104 with respect to the hull of the boat 110 may also be adjusted to change the direction in which the light propagated by the LEDs 102 a to d is focussed.
Light fixture 100 provides the effect that the heat generated by the LEDs 102 a to d is directed out of the light fixture and into an environment external to the light fixture 100. In this example, the mounting of the stepped formation 104 to the hull of the boat using thermally conductive mount 108 enables the heat to be transmitted from the LEDs 102 a to d to the exterior of the hull of the boat 110. The thermal path between the LEDs 102 a to d and the external environment, i.e. the hull of the boat 110, is reduced as the light fixture 100 can be positioned much closer to the external environment.
The use of copper for the stepped formation 104 means that the heat is conducted away from the LEDs quickly as copper is what would be described as highly thermally conductive, with a thermal conductivity of approximately 400 W/mK. This enables the heat to be quickly transferred from the LEDs 102 a to d to the area surrounding the light fixture 100. In the described example, this means that the heat will be conducted from the LEDs 102 a to d through the stepped portion 104 and through the mount 108 onto the exterior of the hull of the boat 110. As the boat 110 is positioned in water in a marine environment, the water will naturally absorb the heat that gathers on the exterior of the hull of the boat 110 thereby providing a natural and effective cooling for the light fixture 100 without any additional cooling required. Using a material such as copper means that high power light sources can be used without fear that they may cause fire on the underside of the hull of the boat 110 or burn out due to the accumulation of heat in the surrounding environment.
Although the example describes the use of copper for the stepped formation 104, other highly thermally conductive materials can be used such as aluminium or graphite sheet.
Although the example describes the use of LEDs 102 a to d as the source of light for the light fixture 100, other light sources may also be used without departing from the scope of the invention.
As is clearly illustrated by Figure 1, the use of light fixture 100 means that the microlens 114 a to d can be used to focus the light emitted by the LEDs 102 a to d to ensure that light travels through the transparent central portion 112 into the surrounding area. Light fixture 100 enables lights to be provided which emit light efficiently without that light being lost within the structure or diverted elsewhere by the structure.

Claims

A light module, the module having a light fixture (100) comprising:
a thermally conductive stepped formation (104) comprising a plurality of steps; and

a plurality of light sources (102) mounted to respective steps (106) on the stepped formation;

characterised in that a plurality of lenses (114) adjustable through an angle in the range 0 to 60 degrees are adapted to focus the light emitted from respective light sources (102), the light module having a thermally conductive mount (108) adapted to mount the light fixture (100) to a surface of a hull of a boat (110).
A light module as claimed in claim 1 wherein the thermally conductive stepped formation (104) comprises a high thermal conductivity material.
A light module as claimed in claim 2 wherein the high thermal conductivity material is copper.
A light module as claimed in claim 2 wherein the high thermal conductivity material is aluminium.
A light module as claimed in claim 1 wherein the thermally conductive stepped formation (104) forms a stepped printed circuit board (PCB) for the plurality of light sources (102).
A light module as claimed claim 1 wherein each of the steps (106) on the thermally conductive stepped formation (104) forms a PCB for the respective mounted light source.
A boat (110) comprising the light module of any of claims 1 to 6 mounted to the hull of the boat (110).