TECHNICAL FIELD

The present disclosure relates to ensuring that illumination in an environment provides a certain luminous flux level through a vertical plane or cylindrical surface (i.e. a great enough component emanates in the horizontal direction). For instance this could be to ensure compliance with a specification of the WELL circadian lighting standard.

BACKGROUND

New lighting recommendations are published in the WELL Building Standard (http://standard.wellcertified.com/light/circadian-lighting- design). This defines a

recommended melanopic daylight (D65) equivalent, referred to as EML (equivalent melanopic lux), for a variety of scenarios such as work places (e.g. workstations in offices). EML is measured in the vertical plane at a predetermined height above the finished floor corresponding to a typical eye level of the occupant. EML also takes into account luminous intensity and colour temperature. The WELL building standard specifies that EML levels are to be measured during performance verification (the commissioning stage) in order to ensure compliance.

Luminous flux is the measure of the perceived power of light. It is equal to the electromagnetic radiant flux in the visible spectrum weighted per unit frequency according to the luminosity function, which represents the human eye's response to different wavelengths of light. The SI unit is Lumen (lm). Lux (Lx) is the SI unit of luminous flux per unit area

(illuminance), a quantity which may be referred to by the symbol E. Sometimes as a shorthand the quantity E itself (as opposed to the SI unit) is referred to as the“lux” (strictly the illuminance). EML is defined as the lux Ev in a vertical plane or vertical cylindrical surface multiplied by a dimensionless ratio MEF (melanopic equivalence factor), referred to in the WELL Building Standard as the melanopic ratio R, which is a function of correlated colour temperature (CCT) of the lux component at the location in question. It is a metric used to measure the effect of light on a human’s circadian rhythm. It is defined as: The WELL Building Standard ^® , Version 1.0 of October 20 ^th 2014, downloadable at

https://www.wellcertified.com/sites/default/files/resourc es/WELL%20Building%20Standard %20-%20Qct%202014.pdf discloses on page 189-191 the following:

TABLE L 1 : MELANOPIC RATIO

This unit Equivalent Melanopic Lux (EML) was proposed by Lucas and others (Lucas et al, "Measuring and using light in the melanopsin age." Trends in Neuroscience, Jan 2014). The authors provided a toolbox which for a desired spectrum derives equivalent“a-opic” lux for each of the five photoreceptors in the eye (three cones, rods, and the ipRGCs). The authors selected scaling constants such that each of the values would be identical to each other and the standard definition of lux for a light spectrum of perfectly uniform energy (CIE Standard Illuminant E).

Given a spectrum of light, each equivalent a-opic lux is related to each other by a constant. The table below shows the example ratios between the equivalent melanopic lux and the standard visual lux for several sources.

To calculate the equivalent melanopic lux (EML), multiply the visual lux (L) designed for or measured in a building by this ratio (R): EML = L x R. For example, if incandescent lights provide 200 lux in a space, they will also produce 108 equivalent melanopic lux. If daylight is modeled to provide the same visual brightness (200 lux), it will also provide 220 equivalent melanopic lux.

Similar melanopic ratios can be determined by incorporating the spectrum of the desired source into the calculations in Table L2. Projects are encouraged to use this approach to obtain more accurate results. Both the authors of the journal article and the IWBI have spreadsheets to aid in this calculation.

CCT (K) LIGHT SOURCE RATIO

2950 Fluorescent 0.43

2700 LED 0.45

2800 Incandescent 0.54 4000 Fluorescent 0.58

4000 LED 0.76

5450 CIE E (Equal Energy) 1.00

6500 Fluorescent 1.02

6500 Daylight 1.10

7500 Fluorescent 1.11

TABLE L2: MELANOPIC AND VISUAL RESPONSE

To calculate the melanopic ratio of light, start by obtaining the light output of the lamp at each 5 nm increment, either from manufacturer or by using a spectrometer. Then, multiply the output by the melanopic and visual curves given below to get the melanopic and visual responses. Finally, divide the total melanopic response by the total visual response.

EML is thus a measure of adjusted lux per unit area in a defined vertical plane or surface. In the norm today it is measured in the vertical plane but it is also possible this will be changed or added to it that it can also be measured in the cylindrical way. The WELL building standard also specifies that such EML levels should be met at specific heights above the finished floor. This is illustrated schematically in Figure la and lb. Figure la shows a vertical plane VP through a region of a space such as a room, and a horizontal component Ev of the lux in that space as projected onto an elementary area dA in the plane VP at a height h above the floor. The EML is defined as the lux E falling on dA (the luminous flux per unit area) multiplied by MEF(CCT) where CCT is the colour temperature of the lux component E. Figure lb shows the alternative measure of EMF, based on a horizontal component of the lux Ev as projected onto an elementary area dA at a height h on the surface of a vertical cylindrical surface VC. Note the cylindrical surface over which the component is measured doesn’t have to be a full cylinder. E.g. the EMF may be averaged over a half cylindrical surface, or measured at an elementary area dA on a cylindrical surface at a particular point.

Note that EML may equivalently also be defined based on other intensity and spectral information indicative of the lux and colour temperature. E.g. using foot-candles as the measure of intensity in the visible spectrum (i.e. illuminance), a factor equivalent to the MEF can be defined which gives the same EML value for illuminance measured in foot- candles as the above equation would for the same illuminance measured in lux.

For work areas, the WELL building standard specifies that at least one of the following requirements is met. (a) At 75% or more of workstations, at least 200 EML is present, measured on the vertical plane facing forward, 1.2 m above finished floor. This light level may incorporate daylight, and is present for at least the hours between 9:00am and 1 :00pm for every day of the year (b) For all workstations, electric lights (which may include task lighting) provide maintained illuminance on the vertical plane facing forward of 150 EML or greater.

Breakrooms: for workplaces where employees spend most of their time in spaces with light levels limited by work type (such as restaurant servers or hospital ward workers), the WELL building standard specifies that such workplaces have break rooms which meet the following requirement. Lights provide a maintained average of at least 250 EML as measured on the vertical plane facing forward at surfaces 1.2 m above finished floor. The lights may be dimmed in the presence of daylight, but are able to independently achieve these levels. In living environments (e.g. bedrooms, bathrooms, and rooms with windows), the WELL building standard specifies the following (a) 200 or more EML as measured facing the wall in the centre of the room 1.2 m above the finished floor. The lights may be dimmed in the presence of daylight, but are able to independently achieve these levels (b) Lights provide not more than 50 EML (to the extent allowable by code) as measured 0.76 m above the finished floor.

In learning areas, the WELL building standard specifies that at least one of the following requirements is met. (a) Early education, elementary, middle and high schools, and adult education for students primarily under 25 years of age: the light (which may incorporate daylight) must provide at least 125 EML at 75% or more of desks, on the vertical plane facing forward 1.2 m above finished floor. This light level is present for at least 4 hours per day for every day of the year (b) Ambient lights provide maintained illuminance on the vertical plane of EML greater than or equal to the lux recommendations in the Vertical (Ev) Targets in Table 3 of IES-A SI RP-3-13, following the age group category most appropriate for the population serviced by the school. Lor example, art studios in elementary school, middle school, or high school are provided with 150 EML from the electric lights.

SUMMARY

A problem with the existing luminaires today is that they do not provide enough vertical illuminance, i.e. lighting in the vertical plane or a vertical cylindrical surface. This has to do with the existing norms which give more attention to the horizontal work plane and the direct glare control. For instance, typically luminaires as used today are positioned in a horizontal plane, with relatively large spacing between the luminaires and each having a relatively small horizontal light emitting area. These may also be screened from direct view of the occupants by optical parts such as lamellas placed between the light-emitting areas.

The effect of such features is that most of the emitted light is directed downwards towards horizontal work plane and the lighting component directed towards vertical planes is limited.

The present disclosure provides lighting fixtures with a special design to emit a substantive component of both horizontal and vertical illumination. For instance, the horizontal illumination component (i.e. the component illuminating the horizontal plane) may be arranged to meet a certain specification for a workspace plane, e.g. a European standard such as 5001ux on the workspace plane, whilst the vertical illumination component may be arranged to provide a certain equivalent melanopic lux (EML), e.g. to meet one or more of the specifications as described in the WELL building standard. According to one aspect disclosed herein, there is provided a lighting fixture comprising: fitting means adapted for fitting the lighting fixture to a ceiling of a room, a specified ceiling height above a floor of the room; one or more first parts having one or more first lighting surfaces for emitting a first illumination output; and one or more protruding members having one or more second lighting surfaces for emitting a second illumination output. The one or more first lighting surfaces are arranged such that when the fitting means is fitted to the ceiling, the one or more first lighting surfaces face downward from the ceiling so that the first illumination output illuminates a space below the lighting fixture. The one or more protruding members are arranged such that when the fitting means is fitted to the ceiling, the one or more second lighting elements protrude downward from the ceiling with the one or more second light-emitting surfaces facing sideways so that the second illumination output is projected sideways. .

I.e. the first illumination has a substantial vertical illumination component and creates a substantially horizontal illuminance (i.e. a component illuminating a horizontal plane), and the second illumination output has a substantial horizontal illumination component and created a substantially vertical illuminance (i.e. a component illuminating a vertical plane or vertical cylindrical surface). For instance, the second illumination output may be arranged to be directed towards the eyes or face of an occupant of a workstation associated with the lighting fixture when the occupant is stationed (e.g. seated) at the workstation.

In embodiments the one or more protruding members may be arranged such that when the fitting means is fitted to the ceiling, the one or more second lighting surfaces are operable to provide said second illumination output with an equivalent melanopic lux, EML, of at least: (a) 125 EML at a height of l.2m above the floor, or (b) 150 EML at the height of l.2m above the floor, or (c) 200 EML at the height of l.2m above the floor, or (d) 250 EML at the height of l.2m above the floor, or (e) 125 EML at a height of l.5m above the floor, or (f) 150 EML at the height of l.5m above the floor, or (g) 200 EML at the height of l.5m above the floor, or (h) 250 EML at the height of l.5m above the floor, or (i) 125 EML at any height between l.2m and l.7m above the floor, or (j) 150 EML at any height between l.2m and l.7m above the floor, or (k) 200 EML at any height between l.2m and l.7m above the floor, or (1) 250 EML at any height between l.2m and l.7m above the floor, or (m) 125 EML across a range of heights between l.2m and l.7m above the floor, or (n) 150 EML across a range of heights between l.2m and l.7m above the floor, or (o) 200 EML across a range of heights between l.2m and l.7m above the floor, or (p) 250 EML across a range of heights between l.2m and l.7m above the floor.

In embodiments, the second illumination output may have a higher colour temperature than the first illumination output; or a colour temperature of at least one of the first and second illumination outputs may be settable independently of the other such that a higher colour temperature can be set for the second illumination output relative to the first illumination output.

In embodiments, the one or more second lighting surfaces may have a total luminous area greater than that of the one or more first lighting surfaces.

In embodiments the lighting fixture may be arranged so as, when fitted by said fitting means to the ceiling, the first illumination output provides at least 500 lux in a horizontal workspace plane.

In embodiments, the one or more first parts and the protruding members may be integrated into a same luminaire housing, or may be implemented in multiple luminaire housings each integrating at least one of the first parts and at least one of the protruding members into the same housing.

In embodiments, the one or more protruding members may be retrofitted to one or more luminaries comprising the one or more first parts thereby furnishing said one or more luminaires with one or more new protruding members not available or considered necessary at the time of manufacture, sale or installation of said one or more luminaires. The term“retrofit” as used herein refers to (i) furnishing the luminaire with new or modified parts or equipment not available or considered necessary at the time of manufacture of the luminaire, (ii) installing (new or modified parts or equipment) in a luminaire previously manufactured or constructed, or (iii) adapting a luminaire to a new purpose or need.

In embodiments, one, some or all of the one or more protruding members may be arranged to at least partially block a state (e.g. an on/off state or dimmed state) of the first illumination output from being visible in a surrounding area.

In embodiments, one, some or all of the protruding members may comprise a sound absorbing material.

According to another aspect disclosed herein, there is provided a system comprising one or more lighting fixtures installed in an environment comprising one or more rooms, including at least an instance of any of the above-mentioned lighting fixtures installed by said fitting means to the ceiling of each room. In embodiments, the system may further comprise a controller configured to: control a timing of at least the second illumination output so that at least a predefined location within said environment is illuminated with a minimum EML for at least a minimum time schedule, and/or receive an input from an occupancy sensor to detect whether an occupant is present at the predetermined location illuminated by said second illumination output, and based thereon to control the timing of at least the second illumination output so that the occupant is provided with the minimum EML when detected to be at said location.

In embodiments, said minimum time schedule may comprises: at least three hours between 9am and lpm; or at least 4 daytime hours for every day of the year, with at least 2 of these hours between 8am and 1 lam.

In embodiments, the one or more protruding members may be arranged to provide said minimum EML at a workstation of the occupant.

In embodiments the predetermined location is a workstation of the occupant.

In embodiments, the minimum EML may be: 125 EML at a height of 1.2m above the floor, 150 EML at the height of 1.2m above the floor, 200 EML at a height of 1.2m above the floor, or 250 EML at the height of 1.2m above the floor. The minimum EML may be: 125 EML at a height of 1.5m above the floor, 150 EML at the height of 1.5m above the floor, 200 EML at the height of 1.5m above the floor, or 250 EML at the height of 1.5m above the floor. The EML may be 125 EML at any height between 1.2m and 1.7m above the floor, 150 EML at any height between 1.2m and 1.7m above the floor, 200 EML at any height between 1.2m and 1.7m above the floor, or 250 EML at any height between 1.2m and 1.7m above the floor. The minimum EML may be: 125 EML across a range of heights between 1.2m and 1.7m above the floor, 150 EML across a range of heights between l.2m and l.7m above the floor, 200 EML across a range of heights between 1.2m and 1.7m above the floor, or 250 EML across a range of heights between 1.2m and 1.7m above the floor.

In embodiments the controller may be configured to control one or both of the first and second illumination outputs to have a lower colour temperature in winter than in summer, or in a latitude further from the equator than in a latitude closer to the equator.

In embodiments one, some or all of the protruding members may be arranged as acoustic baffles.

According to another aspect disclosed herein, there is provided a method of installing a lighting system, the method comprising: fitting at least one lighting fixture to a ceiling of a room having a floor, the lighting fixture comprising one or more first parts having one or more first lighting surfaces for emitting a first illumination output, and one or more protruding members having one or more second lighting surfaces for emitting a second illumination output, wherein said fitting comprises arranging the lighting fixture such that the one or more first lighting surfaces face downward from the ceiling so that the first illumination output illuminates a space below the light fixture, and the one or more second lighting elements protrude downward from the ceiling with the one or more second lighting surfaces facing sideways; and calibrating the second illumination output to provide, at a specified height above the floor and a specified relative distance to the lighting fixture, at least a specified luminous flux per unit area in a vertical plane.

In an embodiment, the method comprises installing at least one lighting fixture as an acoustic baffle to the ceiling, wherein one, some or all of the one or more protruding members (24) of the at least one lighting fixture comprise a sound absorbing material.

According to another aspect disclosed herein there is provided a lighting system arranged to illuminate a workstation, the lighting system comprising a first lighting device arranged to provide a first illumination output having a vertical illumination component (i.e. a component illuminating a horizontal plane) and a second lighting device arranged to provide a second illumination output having a horizontal illumination component (i.e. a component illuminating a vertical plane or vertical cylindrical surface), wherein the second lighting device is operable to provide at least a minimum specified EML level at the workstation at a specified height above the floor (e.g. any of the above-mentioned EML levels and heights). The second illumination output may be directed toward the eyes or face of an occupant of the workstation when the occupant is stationed at the workstation. The second lighting device may be attached to the first lighting device (e.g. retrofitted to it), or may be implemented in a unit separated from the first lighting device. Preferably the colour temperature of the second illumination output is tuneable independently from that of the first illumination output.

In embodiments the system comprises a controller configured to control a timing of at least the second illumination output so as to provide at least the minimum EML level for at least a minimum time schedule. For example the controller may be configured to control the second lighting device to emit the second illumination output until a

predetermined amount or dose of EML light has been provided to the occupant.

Alternatively, or additionally, the controller may be configured to receive an input from an occupancy sensor to detect whether an occupant is present at the workstation, and to thereby trigger at least the second lighting device to provide the second illumination output with at least the minimum specified EML, at least when the occupant is detected to be present at the workstation. In further alternative or additional embodiments, the controller may enable the occupant him/herself to manually adjust the intensity and/or colour temperature of the second illumination output. In yet further alternative or additional embodiments, the controller may be configured to receive user data from a personal logging system which keeps track of the received EML for the occupant in one or more specified time intervals per day. The tracking system may for example comprise an RFID based tracking system, an indoor positioning system, and/or a sensor on the body of the occupant (e.g. worn on the body, such as a pendant with the sensor facing forward from the breast). For instance the sensor may be connected to a small program (e.g. on a PC or smart phone) to monitor and count the received EMF.

In yet further alternative or additional embodiments, the controller may be configured to automatically adapt a colour temperature of the first illumination output to match a colour temperature of the second illumination output when the second illumination output is activated.

According to yet another embodiment disclosed herein there is provided a luminaire for illuminating a workstation, the luminaire comprising a first lighting device operable to provide an illumination output having a vertical illumination component (i.e. a component illuminating a horizontal plane), and further comprising an optical element (e.g. a reflector) arranged to redirect (e.g. reflect) a portion of the illumination output to create a horizontal illumination component (i.e. a component illuminating a vertical plane). In embodiments the optical element may be rotatable. The first lighting device and optical element may be configured so that the redirected, horizontal illumination component can provide at least a minimum specified EMF level at the workstation at a predetermined height above the floor when the luminaire is arranged to illuminate the workstation (e.g. any of the above-mentioned EML levels and heights). The optical element may be arranged to direct the redirected component toward the eyes or face of an occupant while stationed at the workstation. The optical element may be an integral part of the luminaire or may be retrofitted to the luminaire.

In embodiments the luminaire is part of a system comprising a controller configured to control a timing of the illumination output so as to provide at least the minimum EML level for at least a minimum time schedule. Alternatively or additionally, the controller may be configured to receive an input from an occupancy sensor to detect whether an occupant is present at the workstation, and to thereby trigger the illumination output to be provided with at least the minimum specified EML at least when the occupant is detected to be present at the workstation. In some embodiments the controller may be configured to trigger the illumination output to be provided when then occupant is present within predetermined hours (e.g. 9.00am - l .OOpm).

BRIEF DESCRIPTION OF THE DRAWINGS

To assist understanding of the present disclosure and to show how embodiments may be put into effect, reference is made, by way of example only, to the accompanying drawings in which:

Figure la schematically illustrates luminous flux per unit area on a vertical plane,

Figure lb schematically illustrates luminous flux per unit area on a cylindrical surface,

Figure 2 is a schematic block diagram of a control system,

Figures 3 a to 3 g illustrate some example lighting fixture designs,

Figure 4a to 4e schematically illustrate some further example lighting fixture designs,

Figures 5 a to 5h schematically illustrate yet further options for lighting fixture design, and

Figures 6a to 6d schematically illustrate some designs for a vertical lighting slab.

DETAIFED DESCRIPTION OF EMBODIMENTS

Throughout this description the direction of light, direction of lighting or direction of illumination is defined as the direction of the light rays. The term illuminance is defined as the total luminous flux incident on a surface, per unit area. Horizontal and vertical illumance therefore are the total luminous flux incident on a horizontal and vertical surface respectively, per unit area. When reflected light is not taken into account, horizontal illuminance is generally created with vertical light, vertical lighting or vertical illumination whereas vertical illuminance is generally created with horizontal light, horizontal lighting or horizontal illumination.

The following describes a luminaire arrangement designed specially to create EMF illumination levels. In embodiments the arrangement may also improve acoustic qualities of the illuminated environment, and/or may improve the visual perception of the space by providing the EMF light for one or more occupants in one area without changing the visual perception of the space for the other users. In yet further embodiments, the arrangement may offer energy savings by means of presence detection and/or timing of illumination.

Preferably the design creates horizontal illuminance levels as described in European norms and vertical EML illuminance levels as specified in the WELL building standard.

The solution splits the luminaire into two different controllable devices: a first device for providing a horizontal illuminance with a normal or tuneable white spectrum and optionally glare protection (in itself known to people skilled in the art), and a second device to improve a vertical EML illuminance. The second device may be incorporated into the same housing as the luminaire or may be separate, e.g. retrofitted. According to the disclosure herein, the second device may take the form of a substantially vertical“slab” or other such additional substantially vertical lighting surface or aperture. In embodiments this may optionally also be arranged to improve the acoustic qualities and/or visual impression of the space in general.

The selection of colour temperatures, intensity levels and lighting schedules may be in accordance with the WELL building standard.

When the substantially vertical slabs are installed with tuneable white light sources, they can also be used to create or add to a specific ambience in the non-EML illumination periods, e.g. create‘warm white’ slabs/panels in the winter or‘cold white’ slabs/panels in summer. It is also possible in this way to create warmer light at the end of the day to prepare people for leaving the workplace for going home. And/or, the variation in colour temperature can also help to create special lighting scenes for different activities, like a more cosy ambiance or a more activating or inspiring space experience.

Because the horizontal component of the illumination can be controlled separately from the vertical component, it offers the possibility to reduce the vertical illumination when no one is present in a particular part of the space - leading to energy savings - while keeping the visual impression of the vertical slabs - emitting or non-emitting horizontal illumination - active. In some embodiments, instead on an integrated solution, the vertical slabs can also be added to an existing general lighting installation thereby adding EML light to an existing installation. The arrangement may also be advantageous in offices without a system ceiling, where the vertical slabs bring acoustic and aesthetic quality to the environment (otherwise provided by the system ceiling).

Figure 2 illustrates an example lighting system in accordance with embodiments disclosed herein. The system comprise at least one lighting fixture 4 installed in an environment occupied by at least one occupant 8 (a human). The environment comprises one or more rooms of a building. E.g. in an office building such rooms may take the form of an office room, a meeting room, a breakroom, a canteen, a foyer or reception, or a corridor (and the various rooms will typically include different such types of room). Or in the home the rooms may comprise a living room, kitchen bathroom, one or more bedrooms, etc. The lighting system comprises one or more lighting fixtures 4, preferably at least one in each room. The following will be described from the perspective of a given lighting fixture 4 in a given room 2, but it will be appreciated that the teachings may be duplicated across multiple lighting fixtures 4 in a given room 2 and/or multiple rooms 2.

The lighting fixture 4 comprises a fitting means 9 by which it is fitted to the ceiling 28 of the room 2, such that when thus fitted the lighting fixture 4 is suspended at a defined height above the floor 27 of the room and illuminates a region of space beneath the ceiling 28. The fitting means 9 may take any suitable form and is not limiting in its form (note also that Figure 2 is only schematic). For instance the fitting means 9 may simply take the form of one or more suitable holes in any part of the lighting fixture body or housing or any other member of the lighting fixture 4, for accepting fasteners such as screws, rivets, bolts or the like for fastening the lighting fixture 4 to the ceiling 28. As another example, the fitting means 9 may comprise a clipping, slotting or latching mechanism for clipping, slotting or latching the lighting fixture 4 to the ceiling 28, or a complementary part or parts for accepting such a mechanism installed in the ceiling 28. In another example, the fitting means 9 may comprise one or more flexible suspenders such as wire, cable, rope, twine, one or more straps or a harness, or the like, for suspending the lighting fixture from the ceiling 28; or one or more holes, loops, hooks or the like for attaching to one or more such flexible suspenders attached to the ceiling 28, or any member or body portion by which the fixture 4 can be bound, harnessed, strapped, or cradled from the ceiling 28, etc. In yet further alternatives the fixing means 9 may comprise a suitable adhesive or a surface for accepting such an adhesive to adhere the lighting fixture 4 to the ceiling 28.

When thus fitted, the lighting fixture 4 is arranged to provide, in the space, both a first, downward illumination output 21 comprising a vertical component of illumination (i.e. for illuminating a horizontal plane) and a second, sideways illumination output 25 comprising a horizontal component of illumination (i.e. for illuminating a vertical plane or surface as shown in Figure la and lb). The first illumination output 21 may be a task light or ambient light. The second, sideways illumination output 25 may achieve a certain specified EMF in a vertical plane or surface. Note that where reference is made herein to the illuminance in a horizontal plane or vertical plane or surface, or such like, this does necessarily limit to illumination falling on a tangible plane or surface. In general, the illuminance in a plane or surface may refer either to the flux falling on an actual tangible surface (e.g. a worksurface such as a desk) or passing through an imaginary or abstract mathematical surface in the air.

When fitted by the fitting means 9 to the ceiling 28, the second, sideways illumination output 25 is arranged to illuminate at least a vertical plane or surface in which the eyes or face of an occupant 8 is likely to be, at a predefined height h above the floor 27 corresponding to a typical eye height, at least when the occupant is at a certain specified location or locations within the room 2, e.g. at a workstation 34. The idea is that the sideways illumination component 25 is arranged to meet a certain specified EML level at a defined vertical height or heights h, at at least one horizontal positon or over a range of horizontal positions in the room. For indoor spaces,“floor” may refer herein to the finished floor as specified by the WELL building standard.

For instance the workstation 34 may be a seated workstation such as a desk, and the eye height may be equal to a typical seated eye height. E.g. certain standards such as the WELL building standard specify an eye height of l.2m above the finished floor. However this is not limiting and other eye heights or a range of eye heights could be used (such that the specified EML level is met over said range of eye heights). Further, the EML level could be specified for a standing eye height, e.g. for a standing workstation. For instance a typical standing eye height may be taken as l.5m, or as a range from l.5m to l.6m or l.5m to l.7m (such that the EML level is met over this range). In some embodiments the lighting fixture 4 may be designed to provide the specified EML over all of a range of heights accommodating both seating and standing positions, e.g. 1.2m 1.5m, or up to 1.7m to take into account taller occupants, and/or down to 1.1m at the lower end of the range to take into account smaller occupants.

The specified EML level may for example be any of those specified for various scenarios by the WELL building standard, e.g. 125EML, 150EML, 200EML or 250EML. However the possibility of other specifications is not excluded.

In embodiments, the lighting fixture 4 is also configured so as, when fitted by the fitting means 9 to the ceiling 28, the downward illumination 21 provides at least a specified lux level in a horizontal plane at a defined height h2 above the floor 27 (e.g. at a height of 0.76m above the floor 27 for a seated workspace plane such as a desktop). For example this may be 5001ux in the workspace plane as specified for workplaces in Europe. In embodiments the first illumination output 21 may have a common white light spectrum as used for general lighting and provides the functional lighting needed for the visual tasks. This spectrum may have a standard fixed colour temperature like 3000 or 4000K. It is also an option to have multiple light spectra of tuneable white in which case the colour temperature can vary from warm white to cool white. The first illumination output 21 may be arranged to have a distribution as commonly used for general lighting, e.g. in workplaces. For example, it can have a lambertian (Figure 4a) or a batwing distribution (Figure 4b). As for the second light output 25, the illumination level needed to produce a given EML depends on the colour temperature applied (see for example the table in background section). In embodiments, for this second light distribution 25 it is preferred to use higher colour temperatures (above the 4000K). The higher the colour temperature the easier it will be to realize the EML needed since this depends on a ratio, for example the Melanopic Ratio as defined in the WELL building standard, related to the colour

temperature. E.g. to realize an EML of 250 lux with a 2700K light source it may take twice as much light than to realize this with a 6000K light source. The second illumination 25 has a light distribution which is more horizontal than the first illuminataion 21 (e.g. see Figure 4c).

In embodiments the second illumination output 25 may be arranged so that it meets the specified EML level at the specified height h and horizontal position 34 on its own. Alternatively, it may be arranged such that this EML specification is met by the total of the horizontal component of the second light output 25 plus the horizontal component of any other light contributions present in the room 2, e.g. a more horizontal component of the first illumination output 21 and/or any light entering through one or more windows and/or originating from other light sources (not shown) and having a horizontal illumination component. Similarly, the first light output 21 may be arranged so that it meets the specified horizontal lux level at the specified height h2 and horizontal position 34 on its own.

Alternatively, this horizontal lux specification may be met by the total of the vertical component of the first illumination output 21 plus the vertical component of any other contributions present in the room 2, e.g. a more vertical component of the second

illumination output 25 and/or any light entering through one or more windows (not shown) or originating from other light sources and having a vetical illumination component.

Preferably however windows or other lighting sources are not relied upon, as daylight is not constant or not always present throughout the whole working day and other artificial light sources may be turned off or dimmed down independently of the light fixture 4. In some embodiments the sideways illumination output 25 may simply be fixed, such that whenever it is turned on the specified EML is met at the defined position or positions (and in embodiment similarly for the downward illumination 21). More preferably however, the system further comprises a controller 10 operatively coupled to the lighting fixture 4 in order to control the intensity and/or colour temperature and/or spectral content (spectral power distribution) of at least the second, sideways illumination output 25 emitted by the lighting fixture 4, and in embodiments also of the first, downward illumination output 21. The coupling between the controller 10 and lighting fixture 4 for this purpose may be via any wired and/or wireless means, e.g. via a wired network such as an Ethernet or DALI network, or a wireless network, e.g. a wireless local area network (WLAN) such as a Wi-Fi or ZigBee network, or any combination. Various means of communicating between subsystems of a system will be familiar to a person skilled in the art and will not be discussed at length herein. The controller 10 may be implemented in the form of software stored on one or more memory devices and arranged to run on one or more processing units. Alternatively the controller 10 maybe implemented in hardware, or any combination of hardware and software. The controller 10 may be implemented on any suitable physical unit or units. E.g. it may be implemented on a server, a lighting bridge, or a dedicated control unit; or it may take the form of a distributed function implemented throughout multiple components of the system such as in the lighting fixtures 4 themselves, or a combination of server and bridge, or server and lighting fixtures, etc.

Preferably the first, downwards illumination output 21 is controllable independently of the second, sideways illumination output 25, whether automatically by the controller or manually by the occupant 8 (or another user).

In embodiments where a controller 10 is used, the control maybe performed on a number of bases. In embodiments the controller 10 is operatively coupled to a timer 11, which may for example be internal to the same processor or circuit implementing the controller 10; or which may be external, e.g. on a server, and connected to the controller 10 via any suitable wired or wireless communication means such as those discussed above. The controller 10 is configured with a time schedule which it follows based on the timer 11 in order to automatically control the illumination emitted by the lighting fixture 4, at least to control the second illumination output 25, to ensure the EML specification is met at the specified position (e.g. workstation 34) at the specified height h for at least a minimum time constraint or a minimum time schedule. This may comprise turning the light 25 on and off, dimming it up and down, and/or controlling its colour temperature or spectral content (spectral power distribution). The counting of the received EMI is preferably re-started for every separate day of the year. So, every new day a person starts with 0 EML and then starts adding up received EML.

The time schedule could be simply be that the specified EML is provided over all of the course of a predetermined window of time such as a day, or the daylight hours of a day, or a working day (e.g. 9am to 5pm). Alternatively the criteria may be more complex. For instance, for work areas the WELL building standard defines that 200 EML is present (measured on the vertical plane facing forward, 1.2 m above finished floor) for at least the hours between 9:00 AM and 1:00 PM. Another example of a more complex condition is that a minimal EML illuminance should be present for at least 4 daytime hours for every day of the year, preferably in the morning, with at least 2 of these hours between 8-11 AM.

At other times the controller 10 may turn off, dim down or reduce the colour temperature of the second, sideways light output 25, e.g. to save power or create a different ambience (e.g. a cosier ambience later in the day).

Note: although particular combinations of EML level, height and time constraints are set out in the WELL building standard, the scope of the present disclosure is not bound by those, and other combinations of the above criteria and/or others can be applied. In general any EML level may be combined with any height and any time condition to define an EML specification.

As an alternative or in addition to controlling the timing, the controller 10 may be coupled to an occupancy sensor 6, in order to receive a signal indicative of whether the occupant 8 is present at the workstation 34 (or other such position for which the lighting fixture is arranged to provide EML). Again this coupling may be by any suitable wired or wireless means such as those mentioned above. The occupancy sensor 6 may comprise one or more passive infrared sensors and/or active ultrasound sensors, and/or one or more cameras plus image recognition algorithm (e.g. facial recognition). In other embodiments however the occupancy sensor 6 does not have to take such traditional forms. As another example the occupancy sensor 6 may comprise an RF tag disposed about the occupant’s person and an RF tag reader disposed at the workstation 34, such that when the occupant 8 occupies the workstation 34 he/she implicitly or explicitly scans the tag against the reader and hence registers his/her presence at the workstation 34 (or equivalently the reader could be disposed about the occupant’s person and the tag be located at the workstation34). As a variant of this it is also possible to detect a person by a portable device such as a smart phone he/she is carrying with him/her. As yet another example, the occupancy sensor 6 may take the form of an application installed on a user terminal of the occupant 8 (terminal not shown). This could be a static terminal such as a desktop computer located at the workstation 34 such that when the occupant logs in or uses the terminal, the application registers the presence of the occupant 8. Alternatively the user terminal could be a mobile user terminal such as a laptop, tablet, smartphone or wearable device carried about the occupant’s person, by which the occupant 8 can be recognized, and which is equipped with a localization technology such as a satellite-based localization technology (e.g. GPS) or an indoor localization technology (e.g. indoor positioning based on coded light). In this case the application uses the localization technology to determine when the occupant is at his/her workstation 34.

By whatever means the occupancy detection is implemented, the controller 10 may be configured so as to automatically trigger the second, sideways illumination output 25 to turn on, dim up or increase in colour temperature at least whenever the occupancy of the workstation 34 (or the like) is detected. This way the occupant receives the EML whenever at the workstation, but at other times the second illumination output 25 can be turned off or dimmed down to save power, or have its colour temperature reduced to more match with the illumination in the surrounding areas (e.g. in an open plan office).

As an alternative or in addition to occupancy sensing, it is also possible to connect the controller 10 wirelessly to a wearable sensor (not shown) worn about the person of the occupant 8. For example, the sensor may be placed on the breast area of the occupant facing forwards, e.g. the sensor being integrated into a device taking the form of a pendant worm about the occupant’s neck with the sensor facing forward, or a broach pinned to the occupant’s clothing. As another example the sensor could be integrated into a pair of glasses, e.g. smart glasses, and thereby arranged to sense the light experienced at eye level from the occupant’s perspective. In another example the sensor could be implemented in an earring. Whatever form it takes, this sensor may be arranged to measure the EML at the location of the sensor or information indicative thereof (e.g. the combination of Ev and CTT, or other intensity and spectral information of the currently experience light), and to provide this information to the controller 10. In this way the controller 10 can keep track of the received EML levels over time, e.g. the amount received in a predetermined time window such as 9 am- 1 pm. After receiving enough EML the controller 10 may switch off the EML component at the lighting fixture. The controller 10 (or its functionality) may for instance take the form of an app installed on smart phone or wearable device of the occupant. In some embodiments, an extra correction factor for age may be added to the system. Older people will need more EML since their eye lens is less clear and discoloured towards yellowish allowing less blue light to enter the eye.

In further alternative or additional embodiments, the controller 10 may also enable the occupant him/herself to manually control the second, sideways illumination output 25, to turn it on/off, dim it up/down and/or change its colour temperature spectral content (spectral power distribution). This way the occupant 8 can select when the EML is provided (or another user such as a supervisor or lifestyle coach can select this for them).

In yet further alternative or additional embodiments, the controller 10 maybe configured to take into account seasonal and/or local requirements. In embodiments the controller is configured to adapt the colour temperature of the first and/or second illumination output 21, 25 in dependence on the current season, such that the colour temperature is warmer (lower) in the winter than in the summer. And/or, the controller 10 may be set to a different setting depending on the geographical latitude at which the lighting fixture 4 is installed, such that the colour temperature of the first and/or second illumination output 21,

25 is of a warmer (lower) colour temperature if installed closer to one of the poles of the earth but a cooler (higher) colour temperature if installed closer to the equator. The setting may be set manually by a commissioning technician, or may be set automatically based on the controller automatically detecting its latitude (using any suitable geographic location system for detecting latitude, e.g. geo IP or a satellite based positioning system such as GPS).

The use of the second (horizontal) illumination output 25 to effect these differences is particularly advantageous, because light through a vertical plane or surface (sideways light) has more impact on an occupant’s experience of the space than vertical (downward) light.

Figures 3 a to 3 g illustrate example designs for the lighting fixture 4 in accordance with embodiments disclosed herein. View 102 in figures 3e and 3f is a plan view from underneath the lighting fixture (in a position when fixed on a ceiling), and view 104 is a side view of the lighting fixture (in a position when fixed on a ceiling).

The lighting fixture 4 comprises one or more first parts 20. Where there are multiple first parts 20, these may be different light sources or different parts of a given lighting source. They may be incorporated in the same luminaire housing or separate housings. They provide one or more first luminous surfaces 22, e.g. a respective surface per device or part 20 or a combine surface, which emit(s) the first illumination output 21. E.g. the one or more first lighting surfaces 22 may be square, rectangular or round, or any other shape. When the fitting means 9 is fitted to the ceiling 28, the one or more first luminous surfaces 22 face downwards from the ceiling, projecting the first illumination output 21 vertically downwards to provide a horizontal illuminance. In embodiments the one or more first luminous surfaces 22 maybe parallel with the ceiling 28 when fitted. The first illumination output maybe projected with a beam axis normal to the ceiling 28.

Further, the lighting fixture 4 comprises one or more protruding members 24 which, when the fitting means 9 is fitted to the ceiling 9, project downwards from the ceiling. They have one or more second luminous surfaces 26 (e.g. one or two per member 24) which emit the second illumination output 25. The protruding members are arranged so that, when the lighting fixture is fitted on a ceiling, the one or more second luminous surfaces face outward to project the second illumination output 25 sideways, thus providing horizontal illumination. In embodiments as shown schematically in Figure 3e, when the fixture 4 is fitted, the one or more second luminous surfaces 26 maybe in a plane normal to the ceiling 28 so as to project the second illumination output 25 in a direction parallel to the ceiling 28. Alternatively as shown schematically in Figure 3f, when the fixture 4 is fitted, the one or more second luminous surfaces 26 may be slanted such that the second illumination output is projected slightly downwards, but still with a substantial horizonal component (i.e. the beam axis is subtantially more horizontal than vertical). Note that the term“sideways” as used herein does not limit the second luminous surface 26 to be at exactly 90 degrees to the ceiling, as for example illustrated in Figures 3a to 3d.

Some further examples are illustrated in Figures 3a to 3d. In embodiments the designs of Figures 3a to 3d may represent actual rather than purely schematic designs. Figure 3 a may be considered a lighting fixture comprising six luminaires whereas Figures 3b and 3c have two luminaires and Figure 3d four luminaires, In the illustrated embodiments one or more of the protruding members (24) may comprise one or more of the first parts (20) such that the one or more first illumination surfaces (22) are integrated into the one or more second lighting surfaces.

The protruding member(s) 24 may be integrated in the same luminaire housing as the first part(s) 20, or where the lighting fixture comprises multiple luminaire housings, each housing may incorporate at least one respective first part (20) and at least one of the protruding members 20. Alternatively the protruding member(s) 24 may be implemented in separately housed units from the housing of the first part(s). In embodiments the protruding member(s) 24 may be retrofitted to the luminaire housing of the first part(s) 20, as illustrated in Figures 3f and 3g. In embodiments, the protruding members 24 may take the form of vertical slabs with luminous surfaces 26 on one or both side of the slab.

Thus there is provided a solution to the problem that in known office spaces there is not enough horizontal illumination available. According to the disclosed solution, a specially designed luminaire 4 is provided which has two different light distributions 21, 25 which can be used in combination or separately. Preferably the two light distributions 21, 25 can be controlled independently of one another. This results in an installation in which a second light distribution 25 (the EML lighting) can be added to the normal (functional) general lighting 21 during the hours in which specified EML levels should be reached, e.g. according to the WELL building standard. In embodiments, the protruding member(s) 24 of the lighting fixture 4 which provides the EML lighting also has a decorative function. And/or, in some cases the protruding member(s) 24 may help to improve the acoustic qualities of the space by incorporating a sound-absorbing material and arranged to act as acoustic baffles.

The first light distribution 21 (for functional lighting) is aimed downward.

This first light distribution 21 can have a light distribution and glare control solution as commonly used for general lighting in working places to fulfil the European norms, e.g. to make sure that the fixture 4 should provide at least 500 lux in the horizontal plane (on desk level), and in embodiments also to meet minimal requirements regarding the illumination levels on the immediate surroundings and the vertical planes. For this functional lighting, white light of 3000 or 4000 K may be used. Another option is to use tuneable white light.

This can be realized with optics as used today such as in the PowerBalance luminaire. This kind of luminaires however produces most of its illumination in the horizontal plane. They fulfil the European norms but do not provide enough vertical illuminance to reach the EML levels specified in the WELL building standard.

Therefore to increase the EML levels in the vertical plane (or vertical cylindrical EML) a second lighting element 24 is added to the lighting fixture 4, hereinbefore referred to as the protruding member. This second lighting element may have a form factor of a vertical panel. In some embodiments this panel is made with sound absorbing materials, for example with a textile or other sound absorbing material being placed between the LEDs or light sources in the panel. By adding these panels the sound reverberation time in the space will be reduced. The vertical position of the panels 24 make them suitable for acoustic absorption and for increasing the horizontal illumination to reach illuminance levels in the vertical plane as needed to reach the vertical EML levels as described in the WELL building standard. In embodiments they will have a lambertian light distribution. The spectrum of the light emitted from the vertical slabs 24 of the luminaire may be a standard white light spectrum with a colour temperature (CCT) of 3000 or 4000K. It may be preferred to create these spectra with tuneable white light. This will give the option to emit“normal” white light at some times, but in the hours when the EML lighting is required it is possible to increase the CCT (e.g. from 3000K to 5000K). This makes it easier to reach the EML levels needed since the colour temperature determines the Melanopic Ratio and will influence the illumination level needed, as given in the table reproduced in the background section.

The vertical slabs 24 may also have a big impact on the visual experience of the space. Looking into the space beneath the luminaire 4 from an occupant’s perspective, the vertical slabs 24 under the ceiling 28 may be quite dominant and influence the total visual impression of the space. This is not the case with the horizontal parts 20 of the luminaire (which looks like for e.g. a normal PowerBalance luminaire). These parts 20 will mainly produce illumination in the horizontal plane which has less visual impact when looking into the space from a distance. Thus the vertical slabs 24 really add to the visual impression of the space. This makes it possible to switch off or dim the functional lighting 21 when there are no people present in a certain part of the space. People working in another part of the space will hardly see the functional lighting 21 is reduced since the vertical slabs 24 still make the unoccupied space appear lit. Without the vertical slabs 24, people would be looking into a “black hole”. In other words the state of the vertical (downward) lighting 21 is at least partially hidden from the perspective of areas not immediately beneath it. This will make it possible to reduce the energy consumption in the space while keeping an attractive impression when looking into the unoccupied region.

Further, by using tuneable white in the vertical slabs 24, the EML levels can be supported by adding cooler vertical light during the hours the EML lighting is required. The tuneable white light also makes it possible to give the vertical slabs 24 a warm or cool white impression. This can help to change the overall impression in the space. In wintertime the warmer lighting can help to create a warmer impression enabling to reduce heating cost. In summertime the cooler lighting can help to establish a cooler impression reducing air- conditioning cost. The vertical slab 24 may have a relatively big surface which will mean that the brightness (direct glare) in the vertical plane is can be limited (spread out over a bigger surface which will add to the visual comfort of the users).

Optical lighting solutions that can be applied to realize the vertical slabs can include for example back-lighting behind a translucent material, and/or an indirect lighting arrangement whereby the sideways illumination 25 is aimed from the top or below to a reflective surface which directs the light into the eye of the occupant 8. An example is illustrated in Figure 6a. Here the vertical slab 24 comprises a housing part comprising an opaque body part 36 and a diffuser 40, which constitutes the luminous surface 26 and in embodiments may comprise a sound absorbing light tranmissive textile, with an illumination element 38 such as an LED or a string or array of LEDs being housed inside the housing part along with a reflector 42. The illumination element 38 and reflector 42 are arranged relative to one another and the housing part such that the illumination emitted by the lighting element 38 is reflected via the reflector 42 out through the diffuser 40. The diffuser 40 is arranged to face sideways (arranged in the vertical plane or slanted somewhat) when the slab 24 is fitted to the ceiling 28. Thus the light reflected from the reflector 42 out through the diffuser 40 is projected sideways and thus forms (at least part of) the desired EML light 25. The relatively large reflecting surface 42 will limit the brightness needs, which will add to the visual comfort. In some embodiments, when the EML lighting 25 is not activated vertical slab 24 can instead be used for decorative lighting effects as well. For example, by also adding RGB LEDs to the light source also, natural lighting effects can be realized, adding to the user experience of the space.

Some alternative designs for the slab 24 are shown in Figure 6b to 6d. Figure 6b shows a design using side-emitting back lighting with a mixing chamber. Figure 6c shows another example of side-emitting back lighting with a mixing chamber. Figure 6d shows an LED array/grid used as back lighting behind the diffuser 40.

In one implementation only the vertical slab is made as a retrofittable part that can be combined with existing general lighting luminaire installations. This will make it possible, in a standard office situation, to reach EML levels which cannot be reached only with the existing general illumination luminaire installation. This way, it is also possible to add quality to the visual experience of the space. Another implementation option is to make a product that can be used in spaces where there is no system ceiling installed. In this case the (extra added) vertical slabs will bring improved acoustic qualities which are otherwise provided by the system ceiling made of acoustic materials.

Figure 3g shows another variant of the lighting fixture design discussed above in relation to Figures 3a-3f. This illustrates that in alternative variants the protruding members 24 and the first parts 20 may be continuous with one another, such as in a“wave” type formation as shown, which undulates between peaks and troughs relative to the ceiling in at least one horizontal direction parallel to the plane of the ceiling. Here the peaks and troughs of the waves (where the gradient is shallowest) form the first parts 20 and first luminous surfaces 22 for emitting the vertical light 21 , whilst the sides of the undulations form the second parts 24 and second luminous surfaces 26 for emitting the sideways (EML) light 25. Note again that“sideways” as referred to herein does not limit the second luminous surface 26 to being in an exactly 90 degrees plane.

Figure 4d illustrates some alternative designs for the lighting fixture 4. In Figure 4d view 106 is a plan view from underneath the lighting fixture when fixed to the ceiling and views l08i to l08iii are side views of alternative variants of the lighting fixture when fixed to the ceiling.

The lighting fixture of Figure 4d comprises a first part 20 comprising at least one first light source arranged to provide vertical lighting 21 and a second part comprising at least one second light source for providing sideways lighting 25. Again the first light distribution 21 (for functional lighting) is aimed downward. This light distribution 21 may again have a light distribution as commonly used for general lighting in working places, e.g. a lambertian (Figure 4a) or a batwing (Figure 4b) form of light distribution. Other forms are also possible. This first light distribution 21 is realized with common white light spectra as used for general lighting and it provides the functional lighting needed for the visual tasks. This spectra can be a standard fixed colour temperature like 3000 or 4000K. It is also an option to have this light as tuneable white in which case the colour temperature can vary from warm white to cool white.

The first light source 20 providing the downward lighting 21 can be a common square or rectangular form, but it is also an option to go for a round or elliptical product form. The light source 20 may be a pre-existing luminaire to which the second source 24 is to be retrofitted. The idea works for both recessed, surface mounted and suspended luminaires.

The secondary light source 24 is configured with a special light distribution 25 which is more horizontal (Figure 4c). This EMF light distribution 25 can be added to the first light distribution 21. It has a more horizontal component to create a high illuminance level in the vertical plane. In some embodiments this vertical illuminance level may be achieved using asymmetrical light. This asymmetric light distribution helps to create an

omnidirectional vertical illuminance at, e.g., l .2m to 1.5 meters above the floor 27 (on eye level of the users). For this secondary light distribution 25 it may be preferred to use higher colour temperatures (above the 4000K). The higher the colour temperature the easier it will be to realize the EMF levels needed since this depends on the Melanopic Ratio related to the colour temperature (see table in background section). As one can see to realize an EMF of 250 lux with a 2700K light source it will take twice as much light compared to realizing this with a light source having a colour temperature of 6000K.

When the first light source 20 is a tuneable white source, the option also exists to set the tuneable white light to the same colour temperature which is provided by the secondary light source 24 during the operating time of the secondary light source 24. This will have the advantage that there will be no difference in colour temperature of light perceived in the environment which can otherwise lead to unwanted colour shift or colour shadow effects. I.e. to avoid unwanted colour shifts or colour shadows when the two light sources are active the colour temperature of the task lighting 21 may be set to the same colour temperature as the EML lighting 25 when the EML is active. In embodiments the controller 10 may be configured to activate a special setting such that at the moment the EML lighting 25 is activated, the colour temperature of the general lighting 21 is also made the same, i.e. an over-rule setting. The advantage would be that it will avoid disturbing colour shifts or colour shadows when both sub systems are active.

The secondary light source 24 can be integrated with the first light source 20 into a new luminaire, i.e. a completely integrated solution in which a luminaire 4 contains two different light sources 20, 24, one for the functional and one for the EML lighting.

Alternatively the second light source 24 may be implemented as an-add on device that can be added to a pre-existing luminaire 4 comprising the first light source 20.

This can be used in combination with a standard luminaire in a new installation.

Figure 4e illustrates another variant in which the second (EML) light source 24 is implemented in another, separate light fixture which can be installed in combination with an already installed lighting installation. I.e. the first and second light sources 20, 24 are implemented in completely separate luminaires 4. In this case the EML luminaire 24 with the horizontal light distribution may be positioned between the functional lighting luminaires 20, preferably in such a way that is covers the complete room.

Yet further alternatives for a luminaire designs are illustrated in Figures 5a to 5h.

Figures 5a to 5c illustrate the idea of an additional secondary lighting source to be used in combination with a task light luminaire such as a desk lamp in order to realize a specified EML level, e.g. to address feature 54 of the WELL building standard related to circadian lighting design. EML should ideally be omnidirectional, i.e. the EML light should come from all around. In practice however workers 8 spend a lot of their time behind a desk 34 and their head position is quite fixed with their eyes fixed mostly on the screen at a distance of about 500mm from the display, or on their desk’s working plane. This situation makes it possible to add a special task lighting luminaire which helps to realize the lighting requirement as described in the new WELL building standard.

In the WELL building standard there is a remark which says that instead of a ‘fixed installation’, additional task lights can be used in order to meet the feature 54 requirements. For on-site verification, several of these desk lamps have to be provided to prove that feature 54 of the WELL building standard (250 lux EML) is met. These tasks lights should be supplied to the desk user on request and one needs to prove that there is sufficient funding to outfit 75% of the workstations with such desk lamps.

Although in the WELL building standard the task light is described as a desk light which can be supplied to workers. The below described principle can also be added to a free floor-standing or a suspended task light luminaire.

In the solution shown in Figure 5a, an extra light source for providing horizontal EML light 25 is added to the task light fixture 4 in order to realize a specified EML level, e.g. the circadian light levels as described in the WELL building standard.

The colour temperature (CTT) of the EML light 25 may vary between for example 3000 to 6500K and maybe used to control the Melanopic Ratio of light. When the CCT is lower (warmer light impression) the amount of light needed falling in the eyes should be higher to trigger the same circadian effects. In general the EML is based on a combination of the amount of light and the colour temperature of the light. In the embodiment of Figure 5a the EML light distribution 25 is directed in such a form that it falls mainly into the eye of the observer (worker) 8. So ideally, the EML light should come from the front and directed directly into the eye of the worker 8. Therefore the desk task luminaire is positioned so that the extra light source realizes the EML illumination in a horizontal plane.

In embodiments, the task luminaire 4 may be combined with an app or other such software program or an app to be installed on the occupant’s PC or smart phone which registers the time that he/she is working at a certain workplace (desk), and in response to trigger the EML light 25. Other forms of occupancy sensor could also be used.

As shown in Figure 5 a, a first implementation is to install a tuneable white light source in the task desk luminaire as its main light source to produce task lighting 21. By adding intelligence to the luminaire 4 the user 8 can enable or activate the EML lighting 25 and a timer will automatically control the light and change the colour temperature preferred according to the WELL building standard and the time of the day. Normally this will mean that for example between lOam and 12 o’clock noon the colour temperature will go up for example from 3000K to 5000K. It is also possible that in combination with colour temperature, the light output (flux) will be also be increased to a higher level. After a certain time (for example after 4pm) the colour temperature will go back to a warmer impression like 3000K, and/or the illumination level will go down, or a combination of a warmer colour temperature and a lower level will be established. This is to avoid that the body reflexes of people will be over stimulated or stimulated in the wrong way.

Another possibility is to provide the occupant 8 with a personal device which sets the EML lighting 25. In this case, when present in a workplace, the occupant 8 is recognized and the controller 10 will determine how much EML the occupant has already received that day. In response the controller can then take actions to provide the missing EML light in the time left.

Figure 5b shows a variant where the luminaire 4, in which the task and EML light sources are included, takes the form of a free floor standing luminaire 4 rather than a desk standing luminaire as in Figure 5a. Figure 5c shows a variant where the luminaire 4, in which the task and EML light sources are included, takes the form of a luminaire 4 suspended from the ceiling 28.

As shown in Figures 5d and 5e, a second implementation is to add to a desk task luminaire 4, instead of an additional light source, an additional reflector (or other optical redirection means) 30, which enables the luminaire to increase the horizontal light output into the direction of the worker 8. So when the light from the luminaire 4 is switched on, the user 8 can rotate the extra reflector 30 to aim more light into the direction of his/hers eyes. View 110 in Figure 5e shows the normal task light situation, whilst view 112 shows how the more horizontal EML light distribution is realized by putting the adjustable reflector (mirror) 30 in the EML positon, thus resulting in a higher vertical illuminance on the face of the worker.

Like in Figures 5a-5c, the reflector 30 of Figures 5d and 5e may be integrated in a desk luminaire as shown in Figure 5d, or in a free standing or ceiling-suspended luminaire analogous to Figures 5b and 5c.

A third implementation is to add to the luminaire 4, which includes the task light source for providing task light 21, an extra secondary light unit which works independently from the task light unit. This extra EML unit is made in such a way that the light distribution it produces results in a vertical illuminance level (e.g. at 1.2 m) as described in the WELL building standard. This secondary unit steers the EML light 25 only into the direction of the eye of the worker 8. The centre of the vertical plane to be illuminated should be at 1.2 m above the floor. Also here, with help of a clock and/or a connection to internet, the luminaire 4 knows the time and the right colour temperature for the EML light to be supplied. The system can operate manually or automatically. This extra EML unit does not need to have a full white spectrum. E.g. it will be enough to add (only bluish) light with a colour temperature of 5000K or higher since it will only have to add the EML light 25 and not contribute to the task (work) light 21.

The presence of a person 8 working with the task luminaire 4 may be detected after it is activated, either manually or with a presence sensor ft is also possible to have all the task luminaires in a building providing the same EML light 25 in set time intervals. N.B. the clock system of the EML unit has to be updated depending on the global location (time- zone). ln another example, an installation is provided in a building where at all workstations in the right time interval the EML 25 is activated but still it is over ruled by occupancy detection, so when no one is there it is dimmed or switched off.

Further variants are shown in Figures 5f to 5h. These show the use of an indirect lighting component 21’ reflected from the luminaire 4 onto the occupant 8 via a surface such as the ceiling 28 (in addition to or instead of the task lighting component 21 and/or the EML lighting component 25). Figures 5f to 5h shows this for the desk, floor free standing and ceiling-suspended luminaires respectively. The indirect lighting 21’ can be used for or added to both task lighting and EML lighting ft is less efficient but adds to the aesthetic quality of the space. The indirect lighting 2 G may fulfil the following functions lndirect light 2 G on the ceiling 28 will give an esthetical effect on the space, as it will look higher (architectural lighting). Further, the indirect lighting 2 G will add to the general lighting and task lighting 21 in the horizontal plane ft is not an effective way of creating horizontal illuminance but it can be taken into account. The indirect lighting 21’ will also add to the vertical illuminance, so to the EML.

With any of the designs of Figures 4a to 5h it is also possible to use any of the control features discussed in relation to the designs of Figures 3a to 3g. For instance, the luminaires of any of Figures 4a to 5h may be combined with any of the previously described occupancy detection features to trigger the vertical illumination 21 and/or horizontal illumination 25 in response to presence of an occupant 8. And/or, in any of Figures 4a to 5h the horizontal lighting component 25 can be made a tuneable white light, and again in such cases the EML levels can be supported by adding cooler horizontal light during the hours the EML lighting is required, and/or the tuneable white light also makes it possible to give a warm or cool white impression via the hortizontal illumination 25. E.g. again, in wintertime the warmer lighting can help to create a warmer impression enabling to reduce heating cost, whilst in summertime the cooler lighting can help to establish a cooler impression reducing air-conditioning cost.

Similarly any of the designs of Figures 3a to 3g may be combined with any control features described in relation to any of Figures 4a to 5h. Further, the lighting component designs of Figures 6a-6h are not limited to be used as the vertical slabs of Figures 3 a to 3 g. For example the lighting component of any of Figures 6a to 6h may be suspended from the ceiling 28 or may be used as a floor- or table-standing luminaire.

It will be appreciated that the above embodiments have been described by way of example only. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.