Field of the Invention

The present invention relates to an adjustable lighting device and relates particularly, though not exclusively, to an adjustable lighting device that employs an LED array as the light source.

Background to the Invention Electroluminescence - the creation of light by passing an electrical current through a material - using a diode was first observed in 1907 by English engineer Henry Joseph Round. In 1927 Russian scientist Oleg Losev built on Round's research to invent the first light emitting diode (LED), based on diodes used in radio receivers. In 1961 American experimenters Robert Biard and Gary Pittman, found that gallium arsenide (GaAs) emitted infrared radiation when electric current was applied. They successfully applied for and obtained a patent for the infrared LED.

Not until 1962 did American scientist Nick Holonyak develop red, low-level LEDs. These were extremely expensive, but were followed by the development of mass- produced, affordable low-level LEDs in 1968 for use as indicator lights. The first high-brightness LED was produced in 1992 by Shuji Nakamura, a Japanese engineer. Nakamura's blue LED eventually led to the phosphor-based high efficiency white LEDs used in Brightgreen bulbs today.

LEDs are now being used in many applications, for example, to replace the traditional halogen globes used for internal lighting, such as in downlights and other decorative internal lighting fixtures.

The present invention was developed with a view to providing an adjustable lighting device which employs LEDs as the light source, which may typically be used as an internal decorative light fixture. However it will be evident that any suitable light source may be employed and the the invention is not limited to the use of LEDs.

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(Rule 26) RO/AU References to prior art in this specification are provided for illustrative purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere.

Summary of the Invention

According to one aspect of the present invention there is provided an adjustable lighting device comprising: a light source; a luminaire body on which the light source is supported, the light source facing backwards towards a wall, ceiling or other surface on which the device is mounted; an adjustable support arm mechanically coupled to the luminaire body for attaching the lighting device to the wall, ceiling or other surface, the mechanical coupling permitting pivoting movement of the luminaire body about at least one axis wherein, in use, the direction in which light is directed from the light source to the wall, ceiling or other surface may be varied.

Preferably the mechanical coupling is a ball and socket joint which permits pivoting movement of the luminaire body about multiple axes.

Preferably the lighting device further comprises a diffuser mounted in front of the light source, the diffuser distributing the light from the light source more uniformly onto the wall, ceiling or other surface.

In the preferred embodiment the light source is an LED array. Typically the LEDs are arranged in a circular array on a rear surface of the luminaire body. Preferably the diffuser is also of circular configuration. Typically each LED in the array is fitted with a micro-lens on its front surface. Preferably the luminaire body comprises a mounting plate hich forms a heat sink for the LED array, the mounting plate being provided with a plurality of cooling fins on its rear face.

Typically the lighting device further comprises an opaque grip panel which is attached to the rear of the luminaire body. In the illustrated embodiment the grip

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(Rule 26) RO/AU panel is of rectangular configuration (a square). However it will be appreciated that the grip panel could be of any desired shape or configuration. In use, the grip panel can be gripped on each side to adjust the angle of the lighting device relative to the wall, ceiling or other surface on which it is mounted. · Advantageously the adjustable support arm comprises a first elongate member which is mechanically coupled at one end to the luminaire body, and which is slidably received in one end of a second hollow elongate member, the second elongate member being attachable at the other end to the wall, ceiling or other surface whereby, in use, the support arm is telescopically adjustable by sliding the first member into or out of the second member.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Likewise the word "preferably" or variations such as "preferred", will be understood to imply that a stated integer or group of integers is desirable but not essential to the working of the invention.

Brief Description of the Drawings

The nature of the invention will be better understood from the following detailed description of several specific embodiments of the lighting device, given by way of example only, with reference to the accompanying drawings, in which:

Figure 1 (a) is a rear top isometric view of a first embodiment of a lighting device according to the present invention;

Figures 1 (b), (c) and (d) are a plan elevation, front elevation and side elevation respectively of the lighting device of Figure 1 (a);

Figure 2 is a rear elevation of the lighting device of Figure 1 (a);

Figure 3 is a section view through the line A-A in Figure 2 of the lighting device

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(Rule 26) RO/AU of Figure 1 (a);

Figure 4 is a side elevation of the lighting device of Figure 1 (a) illustrating adjustment of the beam, spread;

Figure 5 is a rear elevation of the lighting device of Figure 1 (a) illustrating adjustment of the light direction; and,

Figures 6 (a) and (b) are a side elevation and plan elevation respectively of the lighting device of Figure 1 (a) further illustrating adjustment of the light direction.

Detailed Description of Preferred Embodiments

A preferred embodiment of an adjustable lighting device 10 in accordance with the invention, as illustrated in Figures 1 to 6, comprises a light source 12 and a luminaire body 14 on which the light source 12 is supported. The light source 12 (see Figure 3) is mounted so that it faces backwards towards a wall, ceiling or other surface on which the device is mounted (not shown). An adjustable support arm 16 is mechanically coupled to the luminaire body 14 for attaching the lighting device 10 to the wall, ceiling or other surface. The mechanical coupling of the adjustable support arm 16 to the luminaire body 14 permits pivoting movement of the luminaire body about at least one axis. In use, the direction in which light is directed from the light source 12 to the wall, ceiling or other surface may be varied.

Thus, for example, if the device 10 is wall mounted in an internal living area, light from the light source 12 may be directed onto the wall to create subtle and decorative lighting effects. The direction and/or angle in which the light is directed may be adjusted via the adjustable support arm 16 to vary the lighting effects. Preferably the mechanical coupling is a ball and socket joint 18 which permits pivoting movement of the luminaire body 14 about multiple axes (i.e. in any direction). Preferably the lighting device further comprises a diffuser 20 mounted in front of the light source 12. The diffuser 20 distributes the light from the light source 12 more uniformly onto the wall, ceiling or other surface. In the described embodiment the light source 12 is an array of LEDs 22 (see Figure 3). The LEDs 22 are arranged in a circular array on a rear surface of the luminaire

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(Rule 26) RO/AU body 14. Preferably the diffuser 20 is also of circular configuration and is made of translucent material. Typically each LED 22 in the array is fitted with a micro-lens on its front surface. As noted above, any suitable light source may be used, and the invention is not limited to the use LEDs. However LEDs are particularly advantageous because of their compact size and improved efficiency (high brightness and low power consumption).

In this embodiment, the luminaire body 14 comprises a mounting plate 24 on which a printed circuit board (PCB) 26 for the LEDs 22 is mounted. The mounting plate 24 also forms a heat sink for the LED array, and is provided with a plurality of cooling · fins 28 on its front face, as can be seen most clearly in Figures 1 (b) and 6(b). The ball of the ball and socket joint 18 is received in a recess formed in the centre of the mounting plate 24, as can be seen most clearly in Figure 3. The diffuser 20 is fastened to the mounting plate 24 by two M2 fasteners (not visible in the drawings). This clamps the PCB 26 to the mounting plate 24 and assembles the ball and socket joint 18.

Typically the lighting device further comprises an opaque grip panel 30 which is attached to the rear of the luminaire body. In the illustrated embodiment the grip panel 30 is formed with a hollow section 32 on each of two opposite sides which may be used as hand grips. In this embodiment the grip panel 30 is of rectangular configuration (a square). However it will be appreciated that the grip panel 30 may be of any desired shape or configuration. In use, the grip panel 30 can be gripped with two hands on each side to adjust the angle of the lighting device 10 relative to the wall, ceiling or other surface on which it is mounted.

Advantageously the adjustable support arm 16 comprises a first elongate member 36 which is mechanically coupled at one end to the luminaire body 14, as can be seen most clearly in Figure 3. The first elongate member 36 is slidably received through one end of a second hollow elongate member 38. The second elongate member 38 is attachable at its other end to the wall, ceiling or other surface on which the device 10 is mounted. Both elongate members 36 and 38 are typically cylindrical in shape. The first elongate member 36 is formed with the ball of the ball and socket joint 18 on its one end. In use, the support arm 16 is teiescopically adjustable by

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(Rule 26) RO/AU sliding the first member 36 into or out of the second member 38. In this way the beam spread of the light source 12 can effectively be adjusted.

Now that a preferred embodiment of the lighting device has been described in detail, it will be apparent that the described embodiment provides a number of advantages over the prior art, including the following:

(1) It can be easily adjusted to modify the direction and spread of the light onto the adjacent wall, ceiling or other surface on which the device 10 is mounted.

(2) It is of simple but robust design and provides an innovative and aesthetically attractive means of changing the ambience of an internal space.

(3) The LED array provides a low-power, high brightness light source, which may also be dimmable if desired.

It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention. For example, the mechanical coupling of the adjustable arm to the luminaire body may be via any suitable coupling, for example, a simple hinge; although a ball and socket joint is preferably because of its versatility. Therefore, it will be appreciated that the scope of the invention is not limited to the specific embodiments described.

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(Rule 26) RO/AU