A LUMINAIRE APPARATUS

The present invention relates to an electrical lighting apparatus in the form of a luminaire apparatus, in particular to a luminaire apparatus suitable for commercial and industrial environments.

The term "luminaire" is an industrial term used to describe an apparatus that gives off light. Simple single bulb luminaries which are commonly used in domestic environments provide insufficient light for industrial or commercial environments. In contrast batten luminaries comprising batten bulbs, reflector and diffuser units are used in commercial and/or industrial environments, however these types of luminaire apparatus provide inadequate light for very large areas. For such areas it has been regarded as being more optically efficient to use a halogen, sodium or mercury luminaire. In contrast to batten luminaire, halogen, sodium or mercury luminaire require large amounts of electrical energy to actually power the lamp and illuminate an area.

The luminaire apparatus disclosed in United Kingdom Patent Specification No. GB 2387646 provides a solution to problems associated with both the use of halogen, sodium or mercury luminaire and batten luminaire in large commercial or industrial environments. Within that luminaire apparatus, batten bulbs are mounted centrally in a set position along the longitudinal axis of a reflector unit. The reflector unit has an interior reflective surface having a generally concave shape along its longitudinal axis. The apparatus provides extremely good lighting for large environments and has proved to be energy efficient over conventional halogen, sodium or mercury apparatuses.

However, the luminaire disclosed in GB 2387646 has a narrow cone-shaped down-light distribution pattern in which results in light emanating downwards and the light distribution pattern spreads through an acute angle such that band of luminance widens as the light travels farther from the bulb. Generally, in use, the luminaire apparatus is mounted at heights within an environment that ensure areas of interest under the apparatus are illuminated properly. However, the areas outside the light distribution region and above the apparatus are not adequately illuminated, thereby creating a tunnel effect.

The tunnel effect causes a particular problem if, for example, the luminaire cannot be mounted at the required height to ensure that areas of interest are adequately illuminated

In such a scenario, for example in a warehouse environment, the tunnel effect will affect the visibility of stock on high shelving. Furthermore, regardless of whether or not stock close to the apparatus is inadequately illuminated, the tunnel effect appears magnified to the human eye due to the stark contrast to the brighter light distribution area underneath the apparatus. This causes a very unpleasant atmosphere to users or workers within the particular environment.

It is an object of the present invention to provide a more energy efficient luminaire apparatus and to seek to alleviate the aforementioned problems.

According to the invention, there is provided a luminaire apparatus comprising optical elements and electrical elements, the optical elements comprising a reflector unit having an inverted substantially parabolic shaped cross sectional profile having an arcuate base portion from which two opposing elongate arms project, the reflector unit having an interior reflective surface and a longitudinal axis, the optical elements further comprising at least one bulb mountable in the interior of the reflector unit and centrally along the said longitudinal axis of the reflector unit by means of at least one lampholder positioned in one of a plurality of operational positions in or adjacent the reflector unit.

An advantage of this luminaire apparatus over known halogen, sodium or mercury luminaire apparatus is that the energy required to power the luminaire apparatus of the invention is significantly lower. Furthermore, the shape of the reflector unit of the luminaire apparatus of the invention has the advantage that the efficiency of the light output ratio has increased overall by approximately 10%. Thus the energy efficiency of the apparatus of the invention is better than the prior art batten apparatus. The provision of a substantially parabolic shaped reflector, with minimal angles and smooth flow characteristic further contributes to the efficiency of the light output ratio whilst ensuring reduced glare and better light control.

Preferably, the luminaire apparatus of the invention comprises two or more optical elements, wherein two optical elements are a pair of optical elements, each optical element in a pair being in engagement with a central portion. Conveniently, each optical element in the pair is positioned at opposing sides of the central portion and in engagement with opposing sides of the central portion.

In one embodiment of the luminaire apparatus, the operational positions for each lampholder are located on the central portion. Conveniently, each lampholder is mounted in one of the operational positions on the central portion in or adjacent the reflector unit. Preferably, the lampholders are adapted to move between a plurality of operational positions on the central portion relative to the reflector unit. This feature provides yet a further advantage in that the light distribution pattern can be altered quite easily from a narrow distribution pattern to a medium distribution pattern. This overcomes the disadvantage of mounting the apparatus at heights above areas of interest to ensure that those areas are adequately illuminated. Conveniently, the lampholders position can be altered between the narrow distribution pattern and the medium distribution pattern both on site and at the manufacturing stage.

In a further embodiment of the invention, the central portion houses the electrical elements of the luminaire apparatus.

Ideally in one embodiment of the invention, the luminaire apparatus of the invention comprises at least one pair of optical elements. In another embodiment of the invention the luminaire apparatus has two pairs of optical elements. In a further embodiment of the invention the luminaire apparatus may have three pairs of optical elements. It is of course understood that the luminaire apparatus of the present invention can have any number of optical elements attached to the central portion.

The advantage of this arrangement of the luminaire apparatus is that the improvements to the apparatus achieve greater energy efficiency by virtue of the increased light output ratio and photometric performance.

In yet another embodiment of the invention, the luminaire apparatus comprises two bulbs which are mounted in the interior of each reflector unit, wherein each bulb is positioned at an angle relative to each other. Preferably, a first of said at least two bulbs is arranged within the reflector unit at an angle within a range of 80-100° relative to a second of said at least two bulbs. Alternatively, a first of said at least two bulbs is arranged within the reflector unit at an angle within a range of 40-50° relative to a second of said at least two bulbs.

The advantage of this is to improve the light output from each optical element, thus further improving the efficiency of the apparatus of the invention.

Conveniently the luminaire apparatus of the invention can be contained within a housing as a sealed or open unit. Ideally the housing comprises at least one open panel.

Optionally the open panel may be formed as a door of the housing. Conveniently the open panel of the door may be covered using a refractive material. Optionally the refractive material is a clear material which acts as a light diffuser. Alternatively the material could comprise a polarising material. It is of course understood that any combination of refractive, diffusive or polarising material could be used to cover the opening forming a sealed unit. One of the advantages of covering the open panels is to ensure that glass is contained within the apparatus in the event that a bulb should implode or break. It is also understood that the panel could be left open.

In an alternative embodiment of the invention the optical elements of the luminaire apparatus may be secured to the central portion and are thereby held in position by means of ballasts.

Preferably, the luminaire apparatus of the invention further comprises one or more sensor devices. Ideally the sensor detects levels of light within the building and indeed external influences which would affect the level of illumination required within the building.

Conveniently the sensor device is controlled using an integrated intellect system, which facilitates programming of the apparatus and enables the apparatus to readily accept a command. Conveniently the apparatus can be programmed using a remote PC or handheld unit at commissioning stage or alternatively while in place to set different lighting programmes.

Ideally the user is able to program the intellect system so that when the illuminated area is unoccupied, illumination levels are reduced to a minimum light level. The advantage of this system for the user is that the intellect system provides background lighting while offering a minimal energy consumption e.g. after businesses have shut, retail, commercial or otherwise, it may be preferable to offer background lighting for cleaning of work areas or general highlight of merchandising.

Conveniently the intellect system further provides instantaneous responses to changes in occupancy and natural light which in turn provides for efficient use of the apparatus thus energy during periods of non-occupancy by either switching down or switching off the apparatus. Ideally the intellect system is provided with a default mechanism which enables the lighting apparatus to reduce its power consumption from 100% to 5%, thus maintaining lighting to all apparatus while enhancing lighting quality.

Optionally a program can be uploaded and addressed to either individual lighting apparatuses or globally to all of the apparatuses in place.

In a further embodiment of the invention, the luminaire apparatus can move between different locations within a site. Preferably in this embodiment the apparatus of the invention comprises wheels, rollers or castors on the housing of the luminaire apparatus remote from the optical elements and a track to which the wheels of the luminaire apparatus are attached. It is of course understood that the terms 'wheels' and /or 'track' are not limiting terms any other suitable device known to the skilled person which enables the apparatus to move from one location to another is also understood.

Preferably the luminaire apparatus of the invention is further provided with a height adjusting device wherein the lighting apparatus can be lowered from its position on the ceiling and subsequently returned to its starting position at ceiling level. This facility enables users to lower that apparatus to easily access the fittings for the purpose of changing the light source, for example, if a bulb has blown and then readily return to its original position. The advantage of this is that it allows relamping whilst reducing costs significantly. It also avoids the necessity for scaffolding or the hiring of access equipment and eliminates any safety issues pertaining to relamping.

Advantageously the lighting apparatus can be moved between different locations and also raised and lowered by remotely programming the integrated address system.

The invention will hereinafter be more particularly described with reference to the accompanying drawings which illustrate by way of example only, three embodiments of the invention.

In the drawings:

Figure 1 is an end view of two optical elements of the first embodiment of the luminaire apparatus of the invention;

Figure 2 is a side view of the optical elements of the luminaire apparatus of the invention;

Figure 3 is a side view of the central portion of the luminaire apparatus of the invention;

Figure 4 is an end view of the luminaire apparatus of the invention;

Figure 5 is a cross sectional plan view of the luminaire apparatus of the invention;

Figure 6 is a perspective view of the second embodiment of the closed luminaire apparatus of the invention;

Figure 7 is a perspective view of the third embodiment of the luminaire apparatus of the invention with a housing but without a door;

Figure 8 is a plan view of an open luminaire apparatus of the invention;

Figure 9 is a perspective view of the open luminaire apparatus of Figure 7 showing the innards of the central portion; and

Figure 10 is a sectional end view of a reflector unit of the luminaire apparatus shown in the preceding Figures 1 to 9.

Referring to the drawings, there are shown three different embodiments of the luminaire apparatus of the invention 1 , 2 and 3. The first embodiment of the luminaire apparatus 1 shown in Figures 1 to 5 is a closed unit having a housing 10 and a door 20. The second embodiment of the luminaire apparatus 2 shown in Figure 6 comprises a unit with a housing 10 but without a door. The third embodiment of the luminaire apparatus 3 shown in figures 7 to 9 is an open unit without any housing.

Each embodiment of the luminaire apparatus 1 , 2 and 3 comprises at least one pair of optical elements 100 in engagement with a central portion 30. The embodiments of the luminaire apparatus of the invention shown in the 1 to 8 are of the type that has two pairs of opposed optical elements 100 in engagement with the central portion 30. This type of arrangement is known as a four lamp arrangement. It is easily recognised by the person skilled in the art that the apparatus of the invention could also comprise a two lamp, or six lamp arrangement.

In each of the embodiments, a central portion 30 houses the electrical elements of the apparatus. Each optical element comprises a reflector unit 1 1 having an inverted substantially parabolic shaped cross sectional profile having an arcuate base portion 1 10 from which two opposing elongate arms 1 10a and 1 10b respectively project. The interior surface 11 a of the reflector units 11 is highly reflective. At least one bulb 12 is mounted centrally along the longitudinal axis within the interior of the reflector unit 1 1.

Referring specifically to Figures 1 and 2, bulb 12 is mounted in the interior of each reflector unit 11 and centrally along the said longitudinal axis of the reflector unit 1 1 by means of a lampholder 31 (shown in Figures 3 to 8). The lampholder is secured to the central portion 30 by means of a press fastening mechanism whereby two projecting arms from the lampholder 31 are inserted into openings 32 (shown in Figure 3). The arms of the lampholder 31 are resiliently biased into position and are unable to be removed from the openings 32 without the application of an external force. The lampholder 31 can be secured to the central portion 30 using either openings 32a or 32b to one of two lampholder positions 12a or 12b. The alternate positions for the lampholder 31 are available in each of the embodiments 1 to 3.

Position 32a or 12a accommodates the lampholder 31 such that the distance between the centres of each mounted bulb 12 is 190mm, indicated generally by arrow X, which enables the apparatus 1 to have a narrow light distribution pattern. This arrangement is particularly suited for mounting heights over 8 metres.

In contrast, position 32b or 12b accommodates the bulbs such that the distance between the centres of each mounted bulb 12 is 170mm, indicated generally by arrow Y. The narrower distance between the centres of each mounted bulb 12 enables each embodiment to have a medium light distribution pattern. When the bulbs are in this

position, that is, 170mm centre to centre of the bulbs greater uniformity of light distribution is provided at mounting heights under 7 meters.

The distance separating positions 32a and 32b is approximately 10mm. A user simply applies an external force to lampholder 31 to remove the lampholder 31 from one position for example 32a in order to move it to the other position for example 32b. This overcomes the disadvantage of inadequate Illumination due to the light distribution pattern as the distribution pattern of light is readily altered. This can be done at the time of manufacture of the apparatus or when the apparatus is in situ.

The profile of the reflector unit 1 1 causes the light output ratio each embodiment 1 , 2 and 3 to increase to approximately 92% over known batten type luminaire apparatus. In addition this means that overall output has increased on average by 10%. When taking account of the improvement in uniformity in the medium distribution plane this increase is actually in the order of 18%. On examining the narrow distribution plane, it was discovered that the reflector profile accounts for an 11 % improvement at 12 meters in output when measured at one meter above ground in comparison to the prior art luminaire apparatus. At either distribution pattern, the vertical values at 7 meters, 8 meters and 9 meters have increased by 20% due to the polar design of light beam produced. In all, the improvements to the luminaire apparatus achieve greater energy efficiency by virtue of the increased light output ratio and photometric performance when compared to the known prior art luminaire appparatus.

A series of comparative tests as outlined below were carried out between the prior art apparatus and the new luminaire apparatus of the invention.

TEST ONE

The objective of this test was to determine how many luminaire apparatuses were required and hence the power levels required to illuminate to approximately 200 lux, the same aisle (approximately 50Mx2M), when the apparatuses are suspended at a height of 12M. Calculations are based on the average indirect fraction algorithm. The results shown relate to the present invention being configured according to position 12a, that is, the bulbs being arranged such that the reflector has a 190mm centre and enables the apparatus 1 to have a narrow light distribution pattern.

TEST TWO

The objective of this test was to determine the lux levels within the same room (approximately 10Mx10M), when the apparatuses are suspended at a height of 6M. Calculations are based on the average indirect fraction algorithm. The test results shown relate to the present invention being configured according to position 12b, such that the reflector has a 170mm centre to enable the apparatus 1 to have a medium light distribution pattern.

Referring now to Figures 4 to 7, there is shown a first and second embodiment of the luminaire apparatus 1 and 2 having a housing 10. The optical elements 100 and specifically the reflectors 11 are secured to the housing 10 by securing means at points 10a and 10b (shown in Figure 2) respectively. Optionally the securing means are screws or fixing clips (not shown), however it is understood that any suitable means known to a person skilled in the art can also be used. Although not shown wheels or rollers can be attached to the housing 10 of the luminaire apparatus remote from the bulbs to allow the luminaire apparatus 1 to be moved between two separate locations when in situ.

A door 20 is fitted to the housing 10 of the first embodiment 1 of the luminaire apparatus as shown in Figures 4, 5 and 6. The door is hinged at points 21 (Figure 5) and has two open panels 20a and 20b which may be covered using a refractive material. Optionally the refractive material is a clear material which acts as a light diffuser. Alternatively the material could comprise a polarising material. It is of course understood that any combination of refractive, diffusive or polarising material could be used to cover the openings 20a and 20b in the door 20. It is also understood that the open panels 20a and 20b could be left open. One of the advantages of covering the open panels is to ensure that glass is contained within the apparatus in the event that a bulb should implode or break.

Referring now specifically to Figure 5, there is shown a sensor device 35 which is able to detect levels of light within the building and external influences which would affect the

level of illumination required within the building. Conveniently the sensor device is controlled using an integrated intellect system, which facilitates programming of the luminaire apparatus 1 and enables the apparatus to readily accept a command. This allows the luminaire apparatus 1 to be programmed using a remote PC or handheld unit at commissioning stage or alternatively while in place to set different lighting programmes. A user is able to program the intellect system so that when the illuminated area is unoccupied, illumination levels are reduced to a minimum light level. The integrated intellect system further provides instantaneous responses to changes in occupancy and natural light which in turn provides for efficient use of the luminaire apparatus 1 during periods of non-occupancy by either switching down or switching off the luminaire apparatus 1. Ideally the intellect system is provided with a default mechanism which enables the luminaire apparatus 1 to reduce its power consumption from 100% to 5%, thus maintaining lighting to all luminaire apparatus 1 while enhancing lighting quality. Although only shown in Figure 5, each of the embodiments of the luminaire apparatus can be optionally fitted with a sensor device 35.

Although only shown in Figure 5, it is of course understood that each of the embodiments of the luminaire apparatus can be optionally fitted with a sensor device 35.

Referring to Figures 8 and 9, there is shown a third embodiment of the luminaire apparatus 3 which comprises a central portion 30 to which two pairs of optical elements 12 are attached at opposing sides of the central portion 30. The optical elements are secured in position by means of ballasts (not shown) emanating from the central portion 30.

Figure 10 is a sectional end view of one of the reflector units 1 1 and illustrates alternative arrangements for mounting a pair of bulbs within the unit 1 1. In a first arrangement, each bulb may be connected to the unit 11 via one of the pairs of holes 41 a. When the pair of bulbs are connected in this arrangement there is an angle of about 90° between the two bulbs (i.e. each bulb is mounted within the unit 11 at an angle of 45° to the horizontal) and this creates a wide light distribution pattern.

Alternatively, each bulb may be connected via pairs of holes 40b to thereby position each bulb at an angle of about 46° relative to each other (i.e. each bulb is mounted within unit 1 1 at an angle of 67° to the horizontal). This provides a medium light distribution pattern.

However, in either of the arrangements shown in Fig. 10, tolerance levels of +/- 10% for the angle between the two bulbs are appropriate for obtaining the desired light distribution pattern.

In a further arrangement, a single bulb may be secured to the unit 1 1 via hole pair 40c to provide a narrow light distribution pattern.

It will thus be appreciated that different mounting arrangements for bulbs within the reflector unit 11 are able to be accommodated by the present invention and that by selecting an appropriate arrangement a desired light distribution pattern may be obtained.

It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention as defined in the appended claims.