Abstract
A luminaire (100), comprising at least one light source (110) arranged to emit light source light (120), a light exit window (130), wherein the emitted light is arranged to exit the luminaire through the light exit window as luminaire light (135), wherein the light exit window is configured to influence the luminance, L, of the light source light, for generating a profile of the luminance, LP, of the luminaire light as a function of a length 5 dimension, x, of the light exit window, defined from a center (310) of the light exit window to a periphery (320) of the light exit window.
Claims
1. A luminaire, comprising at least one light source arranged to emit light source light, a light exit window, wherein the emitted light source light is arranged to exit the luminaire through the light exit window as luminaire light, wherein the light exit window is configured to influence or modify the luminance, L, of the light source light, for generating a profile of the luminance, L.sub.P, of the luminaire light as a function of a length dimension, x, of the light exit window, defined from a center of the light exit window to a periphery of the light exit window, wherein the profile of the luminance, L.sub.P, at least comprises a first interval, x.sub.1, of the length dimension, x, comprising a step function, S(x), of the luminance, L.sub.P, with a first gradient, G.sub.1=dL.sub.P/dx, a second interval, x.sub.2, of the length dimension, x, adjacently arranged the first interval, x.sub.1, wherein the second interval, x.sub.2, comprises a function, F(x), of the luminance, L.sub.P, with a second gradient, G.sub.2=dL.sub.P/dx, and a third interval, x.sub.3, of the length dimension, x, adjacently arranged one of the first interval, x.sub.1, and the second interval, x.sub.2, comprising a nominal level, L.sub.n(x), of the luminance, L.sub.P, with a third gradient, G.sub.3=dL.sub.P/dx, wherein one of is fulfilled, and wherein the profile of the luminance L.sub.P in the direction from its center of the light exit window to the periphery of the light exit window comprises a change in luminance, L, from a first luminance, L.sub.1, via the step function, S(x), in luminance comprising at least one of a maximum step luminance L.sub.smax, and a minimum step luminance L.sub.smin, to a second luminance, L.sub.2, wherein L.sub.1, L.sub.2>L.sub.smin and L.sub.1, L.sub.2<L.sub.smax.
2. The luminaire according to claim 1, wherein the step function, S(x), in luminance comprises the maximum step luminance L.sub.smax, and the minimum step luminance L.sub.smin, and the profile of luminance L comprises a sequence in luminance L.sub.1, L.sub.2, L.sub.smin, and L.sub.smax from center to periphery of the light exit window of either L.sub.1-L.sub.smin-L.sub.smax-L.sub.2 or L.sub.1-L.sub.smax-L.sub.smin-L.sub.2, wherein L.sub.smax>L.sub.1, L.sub.2>L.sub.smin.
3. The luminaire according to claim 1, wherein the light exit window comprises a pattern configured to influence or modify the luminance, L, of the light source light into luminaire light.
4. The luminaire according to claim 3, wherein the pattern is defined by a distribution of variable light transmission of the light exit window along the length dimension, x, thereof.
5. The luminaire according to claim 3, wherein the pattern is defined by a distribution of variable texture of the light exit window along the length dimension, x, thereof.
6. The luminaire according to claim 3, wherein the pattern is defined by at least two portions, P.sub.i, of the light exit window, having a respective reflectivity, R.sub.i.
7. The luminaire according to claim 3, wherein the light exit window comprises at least one of a cover element and a foil comprising the pattern.
8. The luminaire according to claim 1, wherein the light exit window comprises an optical element configured to influence or modify the luminance, L and/or L.sub.P, of the light source light and/or luminaire light via beam shaping of said light.
9. The luminaire according to claim 1, wherein, associated with a direction, DR, of the length dimension, x, of the light exit window, defined from the center of the light exit window to the periphery of the light exit window, is fulfilled, and wherein a first portion of the light exit window, defined around the center thereof, has at least one first radial dimension, Ra, comprising one of the second interval, x.sub.2, and the third interval, x.sub.3, and the third interval, x.sub.3.
10. The luminaire according to claim 9, wherein the at least one first radial dimension, Ra, is defined by the first interval, x.sub.1, whereby at least one of the first interval, x.sub.1, and the periphery of the light exit window forms a closed loop.
11. The luminaire according to claim 9, wherein the first portion has a first area, A.sub.1, wherein a first ratio, R.sub.1, between the first area, A.sub.1, and a total area, A, of the light exit window, R.sub.1=A.sub.1/A, fulfills 0.03<R.sub.1<0.14.
12. The luminaire according to claim 1, wherein, associated with a direction, DR, of the length dimension, x, of the light exit window, defined from the center of the light exit window to the periphery of the light exit window, is fulfilled, and wherein a second portion of the light exit window, defined around the center thereof, has at least one second radial dimension, R.sub.b, comprising one of the second interval, x.sub.2, and the third interval, x.sub.3, and the third interval, x.sub.3.
13. The luminaire according to claim 12, wherein the second portion has a second area, A.sub.c, wherein a second ratio, R.sub.2, between the second area, A.sub.c, and a total area, A, of the light exit window, R.sub.2=A.sub.c/A, fulfills R.sub.2>0.86.
14. The luminaire according to claim 1, wherein the first interval, x.sub.1, of the length dimension, x, comprises a change of the luminance, L.sub.P, in a range of 10-100%.
15. The luminaire according to claim 1, wherein a sum, S, of the first interval, x.sub.1, and the second interval, x.sub.2, fulfills 1 cm<S<16 cm.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.
[0028] FIG. 1a schematically shows a luminaire according to an embodiment of the present invention,
[0029] FIG. 1b schematically shows a profile of the luminance generated via the luminaire,
[0030] FIG. 2 schematically shows a light exit window of a luminaire according to an embodiment of the present invention,
[0031] FIGS. 3a-3f schematically show luminaires and profiles of the luminance and the brightness generated via luminaires according to embodiments of the present invention,
[0032] FIGS. 4a-b schematically show luminaires according to embodiments of the present invention, and
[0033] FIG. 5 schematically shows preferred lengths of the length dimension, x, of the light exit window of the luminaire according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0034] FIG. 1a schematically shows a luminaire 100 according to an exemplifying embodiment of the present invention. It should be noted that the size, dimensions, etc. of the luminaire 100 and its components are not to scale. The luminaire 100 comprises at least one light source 110 arranged to emit light source light 120. The light source 110 may, for example, comprise one or more LEDs. The luminaire 100 further comprises a light exit window 130, arranged above the light source(s) 110 with respect to the axis, A. The emitted light source light 120 from the light source(s) 110 is arranged to exit the luminaire 100 through the light exit window 130 as luminaire light 135. It will be appreciated that the light exit window 130 may comprise substantially any material, or any composition of material, which is light-transmissive. The light exit window 130 is configured to influence/modify the luminance, L, of the emitted light source light 120, for generating a profile of the luminance, L.sub.P, of the luminaire light 135 as described in FIG. 1b. For example, the light exit window 130 may comprise a pattern 140 configured to influence the emitted light source light 120 from the light source(s) 110 to create a luminance pattern of the luminance, L.sub.P, of luminaire light 135 exiting the luminaire 100. The pattern 140 may be generated by printing or painting a layer of reflecting (preferred) or absorbing paint on the light exit window 130 of the luminaire 100. There may also be a pattern 140 in outcoupling features (paint dots, facets, chemically or laser etched patches, etc.) of a light guide, in case of an edge-lit luminaire panel (not shown). Other solutions involve a pattern 140 in thickness of the diffuser plate or foil, or a pattern in the shape of beam shaping elements (lenslets, micro-cones, micro-prisms) on a beam shaping optical plate. The pattern 140 is hereby created by local variations in beam shape, meaning that the contrast may reverse for different viewing directions: when the luminous intensity distributions vary locally, a higher luminous intensity in a given direction is typically compensated by a lower luminous intensity in another direction. The light exit window 130 may comprise a cover element and/or a foil 195 comprising the pattern 140, wherein the cover element/foil 195 is indicated by the dashed lines.
[0035] The profile of the luminance, L.sub.P, is generated as a function of a length dimension, x, of the light exit window 130, defined from a center 310 of the light exit window 130 to a periphery 320 of the light exit window 130.
[0036] FIG. 1b schematically shows a profile of the luminance, L.sub.P, having a step function S(x) in luminance with a maximum step luminance, L.sub.smax and a minimum step luminance, L.sub.smin, in between a first luminance, L.sub.1, at the center 310 of the light exit window 130 and a second luminance, L.sub.2, at the periphery 320 of the light exit window 130, generated via the luminaire 100 and the light exit window 130 thereof, as described in FIG. 1a and the associated text. The profile of the luminance, L.sub.P, comprises, at least, a first interval, x.sub.1, of the length dimension, x, comprising a step function, S(x), of the luminance, L.sub.P, with a first gradient, G.sub.1=dL.sub.P/dx. Hence, the change of luminance in the profile of the luminance, L.sub.P, is significant at the first interval, x.sub.1. The profile of the luminance, L.sub.P, further comprises a second interval, x.sub.2, of the length dimension, x, adjacently arranged the first interval, x.sub.1, and indicated on either side of the first interval, x.sub.1. The second interval, x.sub.2, comprises a function, F(x), of the luminance, L.sub.P, with a second gradient, G.sub.2=dL.sub.P/dx. The function, F(x.sub.2) may be substantially any function corresponding to the indicated profile, such as an exponential function, a sine/cosine function, a linear function, etc. Compared to the (significant), sharp change of luminance in the profile of the luminance, L.sub.P, at the first interval, x.sub.1, by the relatively high first gradient, G.sub.1=dL.sub.P/dx, the second gradient, G.sub.2=dL.sub.P/dx of the luminance in the profile of the luminance, L.sub.P, is lower at the second interval, x.sub.2. The profile of the luminance, L.sub.P, further comprises a third interval, x.sub.3, of the length dimension, x, adjacently arranged the second interval, x.sub.2, and indicated on either side of the second interval, x.sub.2. The third interval, x.sub.3, comprises a nominal level, L.sub.n(x), of the luminance, L.sub.P, with a third gradient, G.sub.3=dL.sub.P/dx, being (very) small, such as (almost) zero. Compared to the changes of luminance in the profile of the luminance, L.sub.P, by the first and second gradients at the first and second intervals, x.sub.1, x.sub.2, respectively, the nominal level, L.sub.n(x), represents a relatively small, or even non-existing, change of luminance in the profile of the luminance, L.sub.P, by the third gradient. Hence, the luminance, L.sub.P, is preferably constant in the third interval, x.sub.3. It should be noted, however, that the change of luminance over the first interval, XI, and the change of luminance over the second intervals, x.sub.2, is identical, as shown in FIG. 1b. The profile of the luminance, L.sub.P, may be described mathematically, in that a first condition (sgn (G.sub.1)=1, sgn (G.sub.2)=+1, and |G.sub.1|>G.sub.2>|G.sub.3|) or a second condition (sgn (G.sub.1)=1, sgn (G.sub.2)=1, and G>|G.sub.2|>|G.sub.3|) is fulfilled. Hence, in FIG. 1b, in a direction left to right, the first condition applies, as G.sub.1 is negative (sgn (G.sub.1)=1), i.e. a decrease of the luminance in the profile of the luminance, L.sub.P, and its absolute value is relatively high. G.sub.2, on the other hand, is positive (sgn (G.sub.2)=+1), i.e. an increase of the luminance in the profile of the luminance, L.sub.P, with the relationship |G.sub.1|>G.sub.2>|G.sub.3|. Alternatively, in a direction right to left, the second condition applies, wherein sgn (G.sub.1)=1, sgn (G.sub.2)=1, and G>|G.sub.2|>|G.sub.3| is fulfilled.
[0037] In other words, by the profile of the luminance, L.sub.P, in FIG. 1b as generated by the luminaire 100 comprises a relatively sharp step, S(x.sub.1), whereas the second gradient, G.sub.2, of the function, F(x), of the luminance, L.sub.P, is not as sharp, which in turn, is sharper than the third gradient, G.sub.3, of the nominal level, L.sub.n(x), of the luminance, L.sub.P. The luminaire 100 hereby achieves, via the Cornsweet illusion, a reduced overall glare during operation of the luminaire 100.
[0038] FIG. 2 schematically shows a light exit window 130 of a luminaire according to an embodiment of the present invention. Here, the light exit window 130 is exemplified as having a round shape, but it should be noted that other shapes (e.g. rectangular) are feasible as well. Compared to the orientation of the luminaire 100 in FIG. 1a, with respect to the axis, A, the light exit window 130 in FIG. 2 is shown from above as indicated by the axis, A. In FIG. 2, the light exit window 130 comprises a pattern 140 configured to influence/modify the luminance, L, of the light source light emitted from the light source(s) of the luminaire. Analogously with the schematically indicated pattern 140 of FIG. 1a, it should be noted that the form of the pattern 140 in FIG. 2 is (also) merely indicated for reasons of understanding, and that the pattern 140 may have many different forms in order to influence the luminance. L, of the light source light for achieving the profile of the luminance, L.sub.P of the luminaire light. The lines in the pattern 140 indicate features in the luminance pattern like maxima, minima, or transitions between intervals. Accordingly, the concentric circles of the pattern 140 in FIG. 2 are merely presented as examples, and the pattern 140 may take on many different forms and/or comprise many different features. The pattern 140 may, for example, be achieved by paint. According to one or more other examples, the pattern 140 may be defined by a distribution of variable light transmission of the light exit window 130 along the length dimension, x, thereof and/or be defined by a distribution of variable texture of the light exit window 130 along the length dimension, x, thereof. Furthermore, the pattern 140 may be defined by at least one two portions, P.sub.1, P.sub.2 of the light exit window 130, having a respective reflectivity, R.sub.1, R.sub.2, wherein R.sub.1/R.sub.2. It should be noted that the form, placement, etc., of the first and second portions, P.sub.1, P.sub.2, in FIG. 2 are merely exemplifying and for reasons of understanding, and may be different than those shown in FIG. 2. of the light exit window 130.
[0039] Analogously with FIG. 1a, the light exit window 130 may comprise a cover element and/or a foil 195 comprising the pattern 140. It should be noted that the cover element and/or a foil 195 in FIG. 2 is merely indicated for reasons of understanding that the cover element/foil 195 comprises the pattern 140. Furthermore, the light exit window 130 may comprise an optical element (not shown) configured to influence/modify the luminance, L and/or L.sub.P, of the light source light and/or luminaire light via beam shaping of the light source light and/or luminaire light.
[0040] FIGS. 3a-3f schematically shows luminaires and profiles of the luminance and the brightness generated via luminaires according to embodiments of the present invention.
[0041] FIGS. 3a and 3b schematically show luminaires 100 according to embodiments of the present invention. The profile of the luminance, L.sub.P, in FIG. 3b corresponds to the luminaire 100 shown in FIG. 3a. In turn, the profile of the luminance, L.sub.P, in FIG. 3b corresponds to that shown in FIG. 1b (the intervals x.sub.1, x.sub.2, x.sub.3, and the functions S(x), F(x), Ln(x), are omitted in FIG. 3b, and it is referred to FIG. 1b). In FIG. 3b, the profile of the luminance, L.sub.P, comprises, at least, a first interval, x.sub.1, of the length dimension, x, comprising a step function, S(x), of the luminance, L.sub.P, with a first gradient, G.sub.1=dL.sub.P/dx. The profile of the luminance, L.sub.P, further comprises a second interval, x.sub.2, of the length dimension, x, adjacently arranged the first interval, x.sub.1, wherein the second interval, x.sub.2, comprises a function, F(x), of the luminance, L.sub.P, with a second gradient, G.sub.2=dL.sub.P/dx. The profile of the luminance, L.sub.P, further comprises a third interval, x.sub.3, of the length dimension, x, adjacently arranged the second interval, x.sub.2, comprising a nominal level, L.sub.n(x), of the luminance, L.sub.P, with a third gradient, G.sub.3=dL.sub.P/dx. Associated with a direction, DR, of the length dimension, x, of the light exit window 130, defined from the center 310 of the light exit window 130 to the periphery 320 of the light exit window 130, as indicated in FIG. 3a, the condition (sgn (G.sub.1)=1, sgn (G.sub.2)=+1, and |G.sub.1|>G.sub.2>|G.sub.3|) is fulfilled, as shown by the luminance, L.sub.P, profile in FIG. 3b. The luminance, L.sub.P, profile in FIG. 3b is known to lead to the visual illusion of a step in brightness, as schematically indicated by FIG. 3c (not to scale). As a result, the luminance profile will make the exit window appear as if one side has a higher apparent luminance and the opposite side has a lower apparent luminance, even though the actual luminance may be the same at both sides of the luminance profile. Furthermore, as shown in FIG. 3a, a first (central) portion 300 of the light exit window 130, defined around the center thereof, has a first radius, Ra (exemplified by Ra.sub.1). The first portion 300 may comprise the second interval, x.sub.2, and the third interval, x.sub.3, as indicated by Ra.sub.1 in FIG. 3a. Hence, the first radius, Ra.sub.1, extends from the center of the light exit window 130 to the boundary as may be defined by the first interval, x.sub.1. The first portion 300 may alternatively be bounded by the boundary of the light exit window 130. Alternatively, the first portion 300 comprises (only) the third interval, x.sub.3, as indicated/defined by Raz for a single-sided Cornsweet edge pattern as shown in FIG. 3f. Hence, in FIG. 3f a step function S(x) in luminance with only a minimum step luminance, L.sub.smin, in between a first luminance, L1, at the center of the light exit window and a second luminance, L2, at the periphery of the light exit window.
[0042] In FIG. 3a, the luminaire 100 is divided into two areas: center area, A.sub.1, with apparent luminance L1=L+dL, and rim area, A.sub.2, with apparent luminance L2=LdL, wherein the relation between dL and L, as an example, may be dL=0.2.Math.L. It should be noted that the relation between dL and L merely presents an example, and that relation may vary significantly from depending on the details of the profile (shape, amplitude, width, observer position, etc.).
[0043] The unified glare rating, UGR, is a measure of the glare in a given environment. More specifically, the UGR may be used to predict discomfort glare in interior applications, and in mathematical terms, the UGR is a function of the logarithm of the sum of all glare contributions of the visible light sources in the field of view, divided by the background luminance. The change in the UGR can be determined by adding up the contributions of the two areas, A.sub.1, A.sub.2, as if they are two separate sources, wherein A is the total area:
[00001]
[0044] The just noticeable difference in glare roughly corresponds with 1 UGR point. Taken as a lower limit (UGR=1, wherein the minus sign due to a desired reduction in glare), the relation between the bright center area, A.sub.1, and the total area, A, is A.sub.1=0.14A, which may correspond to a circle with 22 cm diameter in case of an exemplifying diameter of 60 cm of the light exit window. The bright area may even be a bit smaller to have even more glare reduction, but probably not smaller than 10 cm diameter for the example of a light exit window having a diameter of 60 cm, because the Cornsweet edge requires this minimum width. Hence, as described mathematically, and according to the example of FIG. 3d, the first portion 300 has a first area, A.sub.1, wherein a first ratio, R.sub.1, between the first area, A.sub.1, and a total area, A, of the light exit window, R.sub.1=A.sub.1/A, fulfills 0.03<R.sub.1<0.14. It should be noted, however, that the examples of the dimensions of the bright center area, A1, and/or the light exit window may be different for other luminaire (light exit window) sizes and/or different observer distances.
[0045] FIG. 3d comprises a different luminaire 100 compared to that of FIG. 3a, and the associated luminance, L.sub.P, profile of FIG. 3d is different compared to that of FIG. 3b. Associated with a direction, DR, of the length dimension, x, of the light exit window, defined from the center 310 of the light exit window to the periphery 320 of the light exit window according to the luminaire 100 of FIG. 3a, the condition (sgn (G.sub.1)=+1, sgn (G.sub.2)=sgn (G.sub.3)=1, and G>|G.sub.2|>|G.sub.3|) is fulfilled by the profile of the luminance, L.sub.P, of FIG. 3e (the intervals x.sub.1, x.sub.2, x.sub.3, and the functions S(x), F(x), L.sub.n(x), are omitted in FIG. 3e, and it is referred to FIG. 1b). Furthermore, as shown in FIG. 3d, a second portion 305 of the light exit window 130, defined around the center thereof, has a second radius, Rb (exemplified as Rb.sub.2). The second portion 305 may comprise the second interval, x.sub.2, and the third interval, x.sub.3, as indicated by Rb.sub.2 in FIG. 3d. In FIG. 3d, the edge coincides with the edge of the light exit window 130, and the areas outside the light exit window 130 is the ceiling in which the luminaire 100 is placed. FIG. 3d describes the situation of a single-sided Cornsweet pattern, where the first interval, x.sub.1, coincides with the boundary of the light exit window 130, with the (darker) second interval, x.sub.2, on the inside and the third interval, x.sub.3, at the center. This embodiment reduces the brightness of the second (center) portion 305. In this case, there is no third interval, x.sub.3, outside the second portion 305, because the second portion 305 fills the full light exit window 130. The outside area (i.e. outside the light exit window 130) represents a (relatively) dark ceiling, and leads to the relatively dark (compared to the situation without Cornsweet edge) second portion 305 which still is brighter than the ceiling.
[0046] According to an example, it may be desired to have a central portion, A.sub.c, (not shown) as large as possible to reduce glare. For example, a second ratio, R.sub.2, between the second area, A.sub.c, and a total area, A, of the light exit window; R.sub.2=A.sub.c/A, may fulfill R.sub.2>0.86. This may correspond to a circle with 56 cm diameter for the example of a light exit window 130 having a diameter of 60 cm. It is noted that this only leaves a 2 cm edge for the bright area. As this is too small for a full Cornsweet pattern (preferably at least 5 cm is needed for the bright part of the Cornsweet edge), the contrast illusion is likely to be less strong.
[0047] FIGS. 4a-b schematically show luminaires 100 according to embodiments of the present invention. Here, the light exit windows 130 are rectangular (e.g. square). In FIG. 4a, the center portion 300 of the light exit window 130 comprises the second interval, x.sub.2, and the third interval, x.sub.3, whereas the boundary of the center portion 300 is at the first interval, XI (the first, second and third intervals are not indicated in FIG. 4a-b, and it is referred to FIG. 1b). In FIG. 4a, the first interval, x.sub.1, hereby forms a closed loop. The radial dimensions, R, in FIG. 4a, shown in a perpendicular relationship, have the same length. In contrast, the luminaire 100 according to FIG. 4b discloses a center portion 300 which boundary is at the first interval, x.sub.1, and inside the light exit window 130, along a horizontal axis in FIG. 4b, and that the first interval, x.sub.1, is at the edge of the light exit window 130, along a vertical axis in FIG. 4b. The radial dimensions, R.sub.1, R.sub.2, in FIG. 4a, shown in a perpendicular relationship, have different lengths. Hence, whereas the central portion 300 of the light exit window 130 in FIG. 4a has a boundary that is defined by the first interval, x.sub.1, the central portion 305 is partly defined by the first interval, x.sub.1, and partly defined by the boundary of the light exit window 130. In configurations where the center portion boundary is not fully defined by either the first interval, x.sub.1, or a combination of the first interval, x.sub.1, and the boundary of the light exit window 130, the brightness illusion created by the luminance pattern and hence the glare reduction is less strong. This unwanted situation may occur when the first interval, x.sub.1, does not form a closed loop and ends somewhere inside the light exit window 130.
[0048] FIG. 5 schematically shows preferred lengths of the length dimension, x, of the light exit window 130 of the luminaire 100. Studies have shown that the optimum profile width of the luminance, L.sub.P, is about 1 degree, corresponding to the optimum width of the second interval, x.sub.2, as the width of the first interval, x.sub.1, may be negligible. As a typical indoor lighting viewing distance, L.sub.d, i.e. the distance from the light exit window 130/luminaire 100 to a user 155 is 3 m, the sum, S (width) of the first interval, x.sub.1, and the second interval, x.sub.2, of the light exit window 130 should be about tan(=1)*3 m=0.05 m. The width should preferably be larger than =0.5 (corresponding to 0.025 m) and preferably not below =0.2 (corresponding to 0.01 m). On the other hand, a larger width than =1 will enhance the effect, but the increase becomes marginal above =2-3. Hence, the width is preferably less wide than =3 (corresponding to 0.16 m), as in practice, widths larger than 3 usually do not fit within most indoor lighting luminaires (for example, in indoor lighting, a standard luminaire size is often about 0.6 m0.6 m. It should be noted that a ceiling grid spacing may be 60 cm, which results in slightly smaller luminaires, such as 0.58 cm0.58 cm. Larger luminaires may also be used, or alternatively, very slim luminaires such as 10 cm120 cm.
[0049] The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the size(s) and/or form(s) of one or more components of the luminaire 100 (e.g. the light source(s) 110, the light exit window 130, etc.), the forms/profiles of the luminance, L.sub.P, may be different than those shown, etc.
