AUSTRALIA Patents Act 1990 MORT BAY TRADERS PTY LTD COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: A Compact Luminaire The following statement is a full description of this invention including the best method of performing it known to us:- 2 TECHNICAL FIELD The described embodiments relate generally to a compact luminaire in the form of a downlight or recessed light. 5 BACKGROUND Luminaires which are installed into a hollow opening in a ceiling are commonly referred to as downlights or recessed lights. When installed, a downlight gives the appearance of having light shining from a hole in the ceiling which is concentrated in a downward direction as either a broad floodlight or a narrow spotlight. 10 Typically there are four parts to a downlight, the trim, the light source, the light source housing and a driver/transformer. The trim is the visible portion of the light. It is the insert that is seen when looking up into the fixture, and also includes the thin lining around the edge of the light. The light source housing is the fixture itself that is 15 installed inside the ceiling and contains the light source, typically a halogen bulb. The housing's primary purpose is to ensure that no flammable materials come into contact with the light itself, which is typically a halogen bulb. Badly-housed downlights can be a fire hazard, although some downlights are designed to contain a self re-setting thermal switch as a safety measure. The combination of the housing and light source 20 may be referred to as the luminaire. Because halogen bulbs generate a significant amount of heat, Australia's fire safety regulations stipulate that in order to comply fully with building codes there needs to be at least a 20cm clearance above the luminaire, at least a 20cm clearance between any 25 building structure, at least a 20cm clearance between any thermal barrier/insulation and at least a 5cm clearance to the driver/transformer. Figure 1 illustrates a typical layout for a single halogen downlight which meets Australian regulations. However it is not just insulation which poses a threat. Ceiling debris such as rubbish 30 and leaves, rodents and nesting birds can also create a fire hazard which regulations cannot necessarily control. Furthermore, halogen bulbs are problematic, have a high lumen output, they have a short lifespan and therefore require regular replacement which is expensive and time 35 consuming.
3 It is desired to address or ameliorate one or more shortcomings or disadvantages associated with traditional downlights or recessed lights, or to at least provide a useful alternative thereto. 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. 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 A compact luminaire in the form of a down light or a recessed light is provided, the luminaire comprising: a lighting module including a plurality of light emitting diodes to emit light therefrom, the lighting module having a first outer surface and a second inner surface; a driver portion to drive the lighting module; and a housing configured to house both the driver portion and the lighting module, the housing having an opening to expose at least a portion of the first outer surface of the lighting module; wherein the driver portion is adjacent the lighting module and wherein the compact luminaire further comprise a trim and the compact luminaire is configured such that the housing is pivotable with respect to the trim. The driver portion may be an integrated LED driver. The driver portion may be configured to enable dimming and/or remote control capability. The lighting module may comprise an array of light emitting diodes (LEDs). The array may be a circular array or a parallel array. The array may be built up on a printed circuit board.
4 The lighting module may be constructed using chip-on-board (COB) technologies, such a lighting module being refered to as a chip-on-board light emitting diode module. Alternatively the lighting module may be constructed utilising surface mount technology or a combination of through-hole construction and surface mount technology. The lighting module may further comprise a discrete base, wherein the lighting module is affixed to a first side of the base. In such an embodiment the driver portion may be affixed to a second side of the base. The compact luminaire may further comprise an optical lens where the optical lens is positioned to overlie the lighting module. The optical lens may be diffuse. BRIEF DESCRIPTION OF T E DRAWINGS Embodiments are described ir further detail below, by way of example, with reference to the accompanying drawings, in w ich: Figure 1 is a schema ic illustration which illustrates a typical layout for a single halogen downlight which mee s Australian regulations; Figure 2 is a bottom view of a compact luminaire according to some embodiments; Figure 3 is a side view f the compact luminaire illustrated in Fig. 2; Figure 4 is an elevation view of the compact luminaire unit illustrated in Fig. 2; Figure 5 is an elevated view of an optional configuration of the compact luminaire; Figures 6a to 6c illustr te three alternative embodiments of the lighting module of the compact luminaire illustrated in Fig. 2; Figure 7 is a cross section through the compact luminaire illustrated in Fig. 2; and Figure 8 illustrates a c rcuit diagram to implement a PWM function on an NUD4001 driver device.
5 DETAILED DESCRIPTION Referring to figures 2 to 4, an exemplary compact luminaire 202 is provided that includes a trim 204, a housing 206, and a lighting module 208. Like numbers refer to like components throughout the illustrations. 5 A pair of fastening portions 214 in the form of spring levered tabs are provided, each respectively secured to an arm which projects perpendicularly away from the trim 204. The fastening portions 214 facilitate securing the compact luminaire 202 to a surface, such as a wall or ceiling. 10 As is illustrated in Figure 5, the housing 206 is secured to the trim 204 by way of a pair of loose rivets (not shown) which enable the housing 206 to pivot on the rivet axis. In this embodiment the housing 206 is pivotable with respect to the trim 204 by approximately 30 degrees to the horizontal. To effect the maximum extent of pivot, the 15 housing 206 is mechanically blocked in rotation by way of a mechanical stopper 216 (see Figure 4) situated on the trim 204. The compact luminaire 202 comprises a lighting module 208 which includes an array of light emitting diodes (LEDs). The LEDs are provided in what is referred to as a 20 chip-on-board array. Figures 6a to 6c illustrate lighting modules 208 each having a different LED configuration. There are several benefits of using a chip-on-board array over, for instance, surface mounting technology including better temperature management and lower production costs. 25 The driver portion is an integrated LED driver 218. Integrated LED drivers provide a constant current source and are designed to replace discrete solutions for driving LEDs in AC or DC voltage applications. An integrated driver eliminates the need for individual components by combining them into a single small surface mount package which results in a significant reduction of both system cost and board space. 30 Figure 7 illustrates a cross section through the luminaire 202 illustrated in Figure 2. The LED driver 218 is a discrete unit that is connected to the LED array 208 via a positive and negative supply wire 220 (only one of which is shown). Advantageously the driver portion 218 is able to be affixed directly on top of the light module, or in 35 close proximity thereto, thereby ensuring compactness of the luminaire.
6 An example of an LED driver 218 is the NUD4001. It should be noted that the compact luminaire 202 is provided with dimming and remote control capability. A superior method of incorporating dimming functionality is to use pulse width 5 modulation (PWM). Figure 8 shows how to implement a PWM function on an NUD4001 driver device. This is made by adding an external small signal NPN transistor connected between pin 4 and ground. The function of Rext2 is to pull up the pin 4 of the device when the PWM 10 signal in the base of the NPN transistor is low. The average current applied to the LED is directly dependent on the duty cycle (lavg =Ipeak x duty cycle). And the LED's light intensity is directly dependent on the average current I(avg) applied. The circuitry illustrated in figure 8 is to enable any one or more of dimming, colour 15 changing and sequencing of the LEDs. A driver portion with dimming capability results in the ability to dim the LED light output over the full range of 0% to 100%. It should be appreciated that dimming drivers can dim LEDs by reduction in the forward current, pulse width modulation via digital control. With the later method the frequency could range up to hundreds of thousands of modulations per second so that 20 the LED array appears to be continuously lit without the presence of any flicker. In one embodiment, the resultant dimensions of the compact luminaire have a width of 85mm and a height of 45mm. The low recessed profile requires very little room under the ceiling in which it is to be installed. Specifications for a wide beamed compact 25 luminare and a spotlight compact luminare are as follows: Specifications Wide beamed Spot light Beam angle (*) 110 30 Colour temperature (K) 3000-4000 3000-4000 Candela (cd) 100-150 700-1000 Lumen (Im) 260-380 230-350 Advantages of using an array of LEDs is that they have a very long life and therefore do not requiring replacing and they are relatively safe. Additionally, LED arrays do not 30 produce infrared radiation which allows the LED fixtures to be positioned in locations 7 where heating from conventional sources would cause a problem. There is an indiscernible amount of heat generated from an LED. It will be appreciated by persons skilled in the art that numerous variations and/or 5 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.