FIELD OF THE INVENTION
[0001] The present invention relates to the field of lighting, and in particular to luminaires.
BACKGROUND OF THE INVENTION
[0002] The use of artificial lighting is becoming increasingly common, with luminaires becoming
more popular due to their high energy efficiency and flexibility of use. Luminaires
are found in a wide variety of environments, including domestic, industrial, clinical,
educational and/or office environments.
[0003] There is an increasing demand for luminaires that provide a high level of control
over the spread and uniformity of light output therefrom.
SUMMARY OF THE INVENTION
[0004] The invention is defined by the claims.
[0005] According to examples in accordance with an aspect of the invention, there is provided
a luminaire comprising: a single flexible sheet of reflective material, the flexible
sheet being folded to form a plurality of cavities; and a plurality of light emitting
elements, each light emitting element being positioned in a different cavity such
that each cavity forms a reflector for a respective light emitting element.
[0006] The present disclosure provides a luminaire with a flexible construction for ease
of manufacturing (with a single design structure) luminaires of different beam outputs,
e.g., different beam angles, light intensity distributions and so on. More particularly,
the use of a folded flexible sheet of reflective material allows or permits an assembler
of the luminaire to choose or design for different beam intensity outputs, without
the need to construct dedicated alternative designs for the reflector(s) of the light
emitting elements.
[0007] In the context of the present disclosure, a sheet is considered to be a uniform,
integrally formed piece of material having a low thickness (e.g., < 10mm, or <5mm,
or < 1mm). A reflector performs beamshaping on light output by a light emitting element
through reflection alone, e.g., without making use of refraction.
[0008] The plurality of cavities may comprise at least two cavities having different cross-sectional
shapes. In particular, the plurality of cavities may comprise at least five cavities
having different cross-sectional shapes.
[0009] In some examples, each cavity has a width and a depth. The width of each respective
cavity is measured at a base of the respective cavity.
[0010] In some examples, the plurality of cavities comprises cavities of at least two different
depths and/or widths. Thus, the plurality of cavities may comprise cavities of at
least two different depths. Similarly, the plurality of cavities may comprise cavities
of at least two different widths.
[0011] In some examples, the luminaire is configured wherein the width and/or depth of the
cavity varies along a direction in which the respective cavity extends, wherein a
width of a cavity is measured at a base of the cavity.
[0012] In some examples, each cavity has an associated width-depth ratio, being a ratio
between the width and the depth of the cavity; and the plurality of cavities comprises
cavities of at least two different width-depth ratios.
[0013] This approach provides a luminaire with a non-uniform beam output for different light
emitting elements. This can be advantageously configured or designed for achieving
a desired overall beam output of the luminaire.
[0014] In some examples, the plurality of cavities comprises cavities of at least five different
width-depth ratios.
[0015] In some examples, the plurality of cavities are arranged to lie perpendicularly to
a first direction wherein with increasing distance along the first direction, the
width-depth ratio decreases.
[0016] This approach effectively provides a gradient wave reflector, which allows for increased
emission or directing of light towards a particular direction (e.g., in a direction
opposite to the first direction). This provides a system for increasing the intensity
of light in a particular direction with respect to the luminaire.
[0017] Preferably, the depth of each cavity increases with increasing distance along the
first direction.
[0018] The first direction is preferably a direction that originates at one side of the
luminaire and extends to/towards another, opposite side of the luminaire.
[0019] In some examples, the plurality of cavities are arranged to lie perpendicularly to
a second direction; and with increasing distance along the second direction until
a reference point, of the plurality of cavities, is reached, the width-depth ratio
of each cavity increases; and with increasing distance from the reference point along
the second direction, the width-depth ratio of each cavity decreases.
[0020] This design provides asymmetric distribution of light output by the luminaire. This
can, for instance, be used to provide a greater amount of light to a particular location
beneath or otherwise illuminated by the luminaire, compared to other locations.
[0021] In other examples, the plurality of cavities comprises only cavities of a substantially
same size and shape. This approach provides a luminaire with increased overall uniformity
of light output by the luminaire. In particular, the reflector formed by each cavity
acts to perform beamshaping in a similar or identical way, such that the overall shape
of the light output by the luminaire is more uniform, compared to approaches where
the cavities have different sizes and/or shapes.
[0022] Preferably, each cavity in the plurality of cavities is an elongate cavity.
[0023] In some examples, each of the plurality of light emitting elements is of a same type.
Thus, in this approach, the plurality of light emitting elements only require a single
type of stock number of light emitting element. This can significantly reduce cost
and improves recyclability of the luminaire and its components.
[0024] Optionally, each of the light emitting elements comprises an elongate light emitting
element positioned in a respective cavity. For instance, each of the light emitting
elements may be either: at least one discrete LED chip mounted on a single carrier;
or a continuous light emitting band.
[0025] The flexible sheet preferably comprises or is coated with a white and/or specular
material for reflecting light. This reduces absorption by the flexible sheet to provide
a more efficient luminaire.
[0026] In some examples, the flexible sheet is formed of a wood-derived material, such as
paper or cardboard. This ensures that the flexible sheet is formed of a renewable
material for improved environmental impact and recyclability. The present disclosure
also recognizes that a wood-derived material can provide a suitably reflective surface
for acting as a reflector for a plurality of light emitting elements. Alternatively,
the flexible sheet can be polymer or metal.
[0027] There is also provided a method for manufacturing a luminaire, the method comprising:
folding a single flexible sheet of reflective material to form a plurality of cavities;
and positioning a light emitting element in each of the plurality of cavities, such
that each cavity forms a reflector for a respective light emitting element.
[0028] These and other aspects of the invention will be apparent from and elucidated with
reference to the embodiment(s) described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] For a better understanding of the invention, and to show more clearly how it may
be carried into effect, reference will now be made, by way of example only, to the
accompanying drawings, in which:
Fig. 1 illustrates a luminaire according to an embodiment;
Fig. 2 provides a perspective view of the luminaire;
Fig. 3 provides a top-down view of the luminaire;
Fig. 4 provides an enlarged view of a portion of the luminaire;
Fig. 5 illustrates an alternative luminaire;
Fig. 6 provides a perspective view of the alternative luminaire;
Fig. 7 illustrates another luminaire;
Fig. 8 provides a perspective view of the other luminaire;
Fig. 9 illustrates yet another luminaire;
Fig. 10 provides a perspective view of the yet other luminaire;
Fig. 11 provides a top-down view of an alternative luminaire; and
Fig. 12 is a flowchart illustrating steps for a method for manufacturing a luminaire.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0030] The invention will be described with reference to the Figures.
[0031] It should be understood that the detailed description and specific examples, while
indicating exemplary embodiments of the apparatus, systems and methods, are intended
for purposes of illustration only and are not intended to limit the scope of the invention.
These and other features, aspects, and advantages of the apparatus, systems and methods
of the present invention will become better understood from the following description,
appended claims, and accompanying drawings. It should be understood that the Figures
are merely schematic and are not drawn to scale. It should also be understood that
the same reference numerals are used throughout the Figures to indicate the same or
similar parts.
[0032] The invention provides a luminaire in which a single flexible sheet is used to form
a series of reflectors for a plurality of light emitting elements. The single flexible
sheet is folded such that a plurality of cavities or troughs are created. A light
emitting element is positioned in each cavity to form the luminaire.
[0033] Embodiments are based on the realization that quick and easily customizable manufacture
of a luminaire can be achieved by use of a folding technique to form cavities or troughs
into which light emitting elements are to be placed. In particular, it is possible
to create a luminaire with a readily customizable output light distribution.
[0034] Proposed approaches can be employed in any environment in which artificial lighting
is desired, but find particular use in indoor environments such as educational facilities,
clinical facilities, industrial facilities and/or domestic environments.
[0035] Figures 1 to 3 illustrate a luminaire 100 according to an embodiment. Figure 1 provides
a side view of the luminaire, Figure 2 provides a perspective view of the luminaire,
and Figure 3 provides a top-down view of the luminaire.
[0036] The luminaire 100 comprises a single flexible sheet 110 of reflective material. The
single flexible sheet is formed of an integrally formed piece of (flexible) material
that is suited for being folded. In particular, the sheet may have a thickness of
<5mm, e.g., <1mm.
[0037] A reflective material may be any material that reflects more than 50% of received
light, and preferably more than 75% of received light, e.g., more than 90% of received
light. Suitable examples of reflective material are known in the art, and include
any material suited for being folded, e.g., coated plastics, thin sheets of metal,
paper or cardboard, and so on.
[0038] The flexible sheet 110 is folded to form a plurality of cavities 111, 112, 11N. In
particular, the flexible sheet may be folded in a manner analogous to a concertina
fold (sometimes called an accordion fold or zig-zag fold) so as to form a sequence
of cavities or troughs. A cavity is formed of at least three sides, including a base
and two side walls, with an opening to allow the output of light from a light emitting
element positioned in the cavity.
[0039] In the illustrated example, the folding of the flexible sheet forms a series of elongate
cavities. In particular, each cavity is positioned to lie in parallel to each other
cavity.
[0040] The number of cavities N in the plurality of cavities may vary depending upon the
embodiment and/or use case scenario. For instance, in some examples, N is greater
than 2, e.g., greater than 5. In the illustrated example, N = 8.
[0041] The luminaire 100 also comprises a plurality of light emitting elements 121, 122,
12N. Each light emitting element is positioned in a different elongate cavity 111,
112, 11N such that each elongate cavity forms a reflector for a respective light emitting
element. A reflector is an element of a luminaire that performs beamshaping on received
light using reflection, e.g., to control or define a beam angle of light emitted by
the luminaire.
[0042] In the present embodiment, perhaps best illustrated by Figure 3, each light emitting
element 121, 122, 12N comprises an elongate light emitting element positioned in a
respective elongate cavity 111, 112, 11N. Each elongate light emitting element 121,
122, 12N may, for instance, comprise a string of LEDs positioned along a same line
(i.e., positioned linearly).
[0043] Each light emitting element 121, 122, 12N may, for instance, be at least one discrete
LED chip mounted on a single carrier. Thus, each light emitting element may be formed
of a single (respective) LED chip or package having a single carrier and one or more
LEDs positioned linearly on this single carrier.
[0044] In another example, each light emitting element 121, 122, 12N may comprise a continuous
light emitting band or a portion of a continuous light emitting band. Examples of
suitable bands may comprise a plurality of LEDs mounted on flexible substrate such
as an LED ribbon or an OLED ribbon.
[0045] Preferably, each of the plurality of light emitting elements 121, 122, 12N is of
a same type, e.g., each has a same structure, shape, construction and/or are produced
using a same manufacturing process. This increases an ease of manufacturing or assembling
the luminaire 100.
[0046] Proposed embodiments are particularly advantageous when the flexible sheet 110 is
formed of a wood-derived material, such as paper or cardboard. This reduces the environment
impact and improves renewability and recyclability of the sheet 110 (and overall luminaire
100).
[0047] In some examples, the flexible sheet 110 comprises or is coated with a white and/or
specular material for reflecting light. Suitable examples of such materials are well
established in the art. This increases the reflectivity and/or uniformity of light
output by the luminaire 100. As a specific example, it is relatively trivial to prepare
a flexible sheet 110 of a wood-derived material, such as paper or cardboard, that
is white in color.
[0048] Turning back to Figures 1 and 2, the luminaire 100 may also comprise a backplate
130. The (single) flexible sheet 110 may be secured to this backplate 130 for enhanced
robustness and reduced likelihood of the cavities 111, 112, 11N changing shape or
position. The backplate 130 may be formed of any suitable material for a luminaire,
e.g. plastics, metal or even wood (e.g., for improved recyclability). However, it
is preferable that the backplate 130 be formed from a thermally conductive material,
such as metal, which is able to act as a heat sink to reduce a risk of overheating
by the luminaire 100.
[0049] For the sake of clarity, other potential features of the luminaire 100 are not illustrated,
as they do not relate to the underlying inventive concept. These potential features
include: driving and/or powering circuitry, control circuitry, communication circuitry,
mounting mechanism, sensing arrangements, other electronic/electrical interconnects,
light/color filters and so on. The skilled person would be readily capable of including
such elements in a luminaire 100.
[0050] The embodiment illustrated by Figure 1 provides a relatively simple or basic example
in which each cavity 111, 112, 11N or trough is identical (or near-identical) in size
and shape. In this way, the light output from each cavity 111, 112, 11N will have
a similar beam shape and/or angle. For the overall luminaire 100, this provides a
uniform output of light across an area or region illuminated by the luminaire 100.
[0051] However, in other embodiments the size and/or shape of the cavities will be different.
Thus, it is possible for different cavities to have different characteristics. Possible
characteristics that may differ for different embodiments include: cavity width; cavity
depth; and/or cavity pitch. This can be achieved by folding the single sheet 110 differently
to create different types of cavity patterns.
[0052] Thus, the plurality of cavities may comprise cavities of at least two different cross-sectional
shapes, e.g., at least five cross-sectional shapes.
[0053] In some examples, the cavity pitch (i.e., the distance between neighboring cavities)
may change in different regions or subsets of the plurality of cavities. For instance,
the plurality of cavities may comprise at least two sub-sets of two or more cavities,
the cavities of different sub-sets having different (cavity) pitches, such that the
distancing between cavities of one sub-set is different to the distancing between
cavities in another subset. The cavities in a same sub-set neighbor at least one other
cavity in that subset. The at least two sub-sets may comprise at least 5 sub-set for
improved flexibility and control of use.
[0054] Figure 4 provides a cross-sectional view of an example luminaire 100. Figure 4 is
useful for understanding specific characteristics (e.g., dimensions) of a cavity 111,
112 and/or of the plurality of cavities.
[0055] Figure 4 illustrates how a cavity 111, 112 is formed from (only) a base 111A, 112A.on
which the corresponding light emitting element 121, 122 is positioned, and two side
walls 111B, 111C, 112B, 112C. Each side wall 111B, 111C, 112B, 112C is sloped or angled
with respect to the base 111A, 112A so that they are able to together act as a reflector
of light emitted by the light emitting element 121. Light generated by a light emitting
element 121 positioned within the cavity 111 escapes via an aperture 111D.
[0056] As illustrated in Figure 4, the side wall 111C of a first cavity 111 meets the side
wall 112B of a second cavity 112 at a vertex 40. This configuration may hold for all
of the plurality of cavities. Thus, for each cavity, at least one side wall may meet
the side wall of a neighboring cavity at a vertex 40. Put another way, there may be
no additional material of the sheet 110 between the side walls of neighboring cavities.
[0057] Preferably, the bases 111A, 112A of all the cavities 111, 112 are positioned to lie
in a same plane. However, this is not essential.
[0058] A width w of the cavity (or "cavity width") may be a width across the base 111A of
the cavity 111, 112, i.e., a minimum distance between the two side walls 111B, 111C
of the cavity 111, 112. In particular, a width w of the cavity may the smallest distance
across the base 111A of the cavity 111, i.e., the smallest distance between the two
side walls 111B, 111C of the cavity.
[0059] A depth d of the cavity 111, 112 (or "cavity depth") may be a distance between a
plane in which the base 111A, 112A of the cavity lies (i.e., a plane in which the
width w is measured) and a parallel plane that intersects the most distant part of
either side wall 111B, 111C of the cavity.
[0060] A pitch p or cavity pitch may be defined as a distance between two neighboring cavities
111, 112. In particular, the pitch p may be defined as the distance between the center
point of two neighboring cavities.
[0061] An angle θ represents an angle between a side wall 112B and a base 112A of a cavity,
as measured within the cavity itself.
[0062] Figure 4 also more clearly demonstrates the positional relationship between the (single)
flexible sheet 110, the light emitting element(s) 121, 122 and the backplate 130.
[0063] Figures 5 and 6 illustrate a luminaire 200 according to another embodiment. Figure
5 provides a side view of the luminaire and Figure 6 provides a perspective view of
the luminaire.
[0064] The luminaire 200 again comprises a plurality of cavities 211, 212, 21N, which are
positioned in parallel to one another. Other components are similar/identical to previously
described components.
[0065] The luminaire 200 differs from the previously described luminaire in that the size
and shape of each cavity 211, 212, 21N is non-identical. Thus, the luminaire 100 comprises
a (single) flexible sheet 110 that has been folded to form a plurality of non-identical
cavities 211, 212, 21N.
[0066] In particular, the depth d of each cavity 211, 212, 212N is different. In the context
of the present disclosure, the depth d of a cavity is the distance between a plane
in which the base of the cavity lies (e.g., the plane in which the light emitting
element for that cavity is positioned) and a parallel plane that intersects the most
distant part of the sheet 110 that forms or defines the cavity.
[0067] The width w of each cavity 211, 212, 21N is held to be substantially constant. A
width is measured at the base of each cavity.
[0068] In this way, a width-depth ratio R
WD, being a ratio between the width w and depth d, is different for each of the plurality
of cavities. The width-depth ratio R
WD may be defined as follows:

[0069] It will be clear that each cavity is associated with its own width-depth ratio, i.e.,
ratio of width to depth.
[0070] In the illustrated example, each cavity 211, 212, 21N is arranged to lie perpendicularly
to a first direction x
1. In particular, each cavity 211, 212, 21N is positioned to lie in parallel to each
other cavity, and each cavity extends perpendicularly to a first direction x
1.
[0071] The first direction x
1 is a direction from a first side 291 of the luminaire 200 to/towards a second side
292 of the luminaire 200. Thus, increasing distance along the first direction x
1 is equivalent to increasing distance from the first side 291 of the luminaire. A
cavity 211, 212, 21N lies perpendicular to a first direction x
1 if the direction of the cavity 211, 212, 21N (e.g., the direction in which the elongate
cavity stretches) is perpendicular to the first direction.
[0072] The cavities 211, 212, 21N of the present embodiment are configured such that, with
increasing distance along the first direction x
1, the width-depth ratio decreases. In particular, as the width is kept constant or
near constant, the depth of the cavities increases with increasing distance along
the first direction.
[0073] Thus, cavities that are located further from the first side 291 of the luminaire
200 have a lower width-depth ratio than cavities located closer to the first side
291. This is achieved by the cavities being configured such that the cavities that
are located further from the first side 291 of the luminaire 100 have a greater depth
(but same width) than cavities located closer to the first side 291.
[0074] It is noted that the pitch between each cavity remains substantially constant. Similarly,
the angle between the side walls of each cavity and the base of the cavity remains
substantially constant.
[0075] The configuration illustrated by Figure 5 results in a non-uniform distribution of
light output by the overall luminaire 200. In particular, the respective beam angle
of light output from/by each successive cavity 211, 212, 21N will decrease or become
narrower with increasing distance along the first direction (i.e., with increasing
distance from the first side 291). This creates a non-uniform beam distribution, in
particular creating a gradient of light intensity.
[0076] This can be advantageous for illuminating some areas/regions that receive light from
the luminaire to a greater extent than others. This approach can advantageously be
used to highlight such regions (e.g., a location where a speaker/teacher is standing)
or to take account of existing lighting into a room (e.g., through a window) to create
uniform lighting within the room as a whole.
[0077] This configuration also allows for control over glare and beam density.
[0078] Figures 7 and 8 illustrate a luminaire 300 according to another embodiment. Figure
7 provides a side view of the luminaire and Figure 8 provides a perspective view of
the luminaire.
[0079] The luminaire 300 again comprises a plurality of cavities 311, 312, 31N, which are
positioned in parallel to one another. Other components are similar/identical to previously
described components.
[0080] The luminaire 300 differs from the previously described luminaire in that the plurality
of cavities are configured such that, with increasing distance along a second direction
x
2 (e.g., increasing distance from a first side 391), the width-depth ratio of the cavities
initially increases before subsequently decreasing (e.g., when approaching a second
side 392). This is achieved with appropriate folding of the single flexible sheet
110.
[0081] In particular, the plurality of cavities may be arranged to have mirror symmetry.
Thus, as illustrated in Figures 7 and 8, one half of the plurality of cavities is
a mirror reflection of the other half of the plurality of cavities.
[0082] Put another way, the plurality of cavities are arranged to lie perpendicularly to
a second direction x
2. The second direction is similar/identical to the first direction previously described,
e.g., and goes from the first side 391 to/towards the second side 392). With increasing
distance along the second direction x
2 until a reference point 350, of the plurality of cavities, is reached, the width-depth
ratio of each elongate cavity increases. With increasing distance from the reference
point along the second direction (e.g., towards the second side 392), the width-depth
ratio of each elongate cavity decreases.
[0083] In this way, cavities that are located further from the reference point 350 of the
luminaire 200 have a lower width-depth ratio than cavities located closer to the reference
point 350. The reference point may lie midway between the first side 391 and the second
side 392 of the luminaire 300. However, this is not essential and variations may position
the reference point at other positions between the first and second sides of the luminaire.
[0084] Similarly, the closer that a cavity is to either the first side 391 or the second
side 392, the greater the width-depth ratio of that cavity.
[0085] This configuration for the sheet 110 also results in a non-uniform distribution of
light output by the overall luminaire. In particular, the respective beam angle of
light output from/by each successive cavity will decrease or become narrower with
increasing distance from the reference point 350. This creates a non-uniform beam
distribution. The illustrated configuration can be advantageous for controlling glare
and beam density.
[0086] In particular, the illustrated configuration is particularly advantageous for reducing
perceived glare of the luminaire. By positioning cavities of a greater depth at the
sides of the luminaire, the amount of light emitted out of the luminaire at relatively
high angles (with respect to an optical axis) is reduced, thereby reducing perceived
glare.
[0087] Figures 9 and 10 illustrate a luminaire 400 according to yet another embodiment.
Figure 9 provides a side view of the luminaire and Figure 10 provides a perspective
view of the luminaire.
[0088] The luminaire 400 again comprises a (single) flexible sheet 110 that has been folded
to form a plurality of non-identical cavities 411, 412, 41N. A light emitting element
121, 122, 12N is positioned in each cavity 411, 412, 41N.
[0089] Each cavity 411, 412, 41N is configured to have a same depth and width. However,
the angle between each side wall (of the cavity) and the base (of the cavity) is different
for each cavity. This also causes the beam angle of light output by each cavity to
have a different shape.
[0090] In the illustrated example, differently angled side walls are achieved by changing
a pitch between cavities 411, 412, 41N for increased distance along a third direction
x
3. The third direction
X3 is similar/identical to the first/second direction previously described, and goes
from a first side 491 of the luminaire 400 to/towards a second side 492. A pitch p
is a distance between two cavities. A pitch may be defined as the distance between
the center of the base of two cavities.
[0091] In the illustrated example, the angle between the side wall(s) and the base of each
cavity decreases in the range of 180° to 90° (as measured within the cavity itself)
with increasing distance along the third direction. Thus, the closer a cavity is to
the second side 492, the smaller the angle between the side wall(s) and the base of
the cavity (as measured within the cavity itself).
[0092] This configuration for the sheet 110 also results in a non-uniform distribution of
light output by the overall luminaire. In particular, the respective beam angle of
light output from/by each successive cavity will become decrease narrower with increasing
distance from the first side 491. This creates a non-uniform beam distribution. The
illustrated configuration can be advantageous for controlling glare and beam density.
[0093] Figure 11 illustrates a luminaire 500 according to yet another embodiment, and provides
a top-down view of the luminaire 500.
[0094] Rather than the cavities 511, 512, 51N being arranged as parallel elongate cavities,
the cavities are instead arranged in a fan-formation. Conceptually, each cavity 511,
512, 51N is positioned to align with a respective hypothetical line 501, 502, 50N,
wherein all the hypothetical lines intersect at a same intersection point 550.
[0095] In this way, the single flexible sheet 100 is folded analogously to a fan.
[0096] This technique facilitates manipulation of the single flexible sheet into nonlinear
shapes, allowing for increased flexibility and selection of light distribution.
[0097] In particular, in this example, the width of each the cavity varies along a direction
in which the respective cavity extends. It will be appreciated that, in some examples,
the depth of a cavity varies along a direction in which the respective cavity extends.
[0098] The above described example configurations for the single flexible sheet are non-exhaustive,
and serve to demonstrate how various folding configurations of the single flexible
sheet can be used in order to achieve different distributions of light output by the
overall luminaire.
[0099] Figure 12 is a flowchart illustrating a method 1200 for manufacturing or assembling
a luminaire.
[0100] The method 1200 comprises a step 1210 of folding a single flexible sheet of reflective
material to form a plurality of cavities. The method also comprises a step 1220 of
positioning a light emitting element (e.g., a different light emitting element) in
each of the plurality of elongate cavities, such that each elongate cavity forms a
reflector for a respective light emitting element.
[0101] Various folding configurations have been previously illustrated and described, and
could be employed in the method 1200. The skilled person would be readily capable
of modifying the method 1200 to produce any herein described product.
[0102] The proposed method provides highly customizable configurations for the reflector
of the luminaire, thereby providing high customization over the light distribution
and/or output by the luminaire.
[0103] 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.
[0104] 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.
[0105] If the term "adapted to" is used in the claims or description, it is noted the term
"adapted to" is intended to be equivalent to the term "configured to". If the term
"arrangement" is used in the claims or description, it is noted the term "arrangement"
is intended to be equivalent to the term "system", and vice versa.
[0106] Any reference signs in the claims should not be construed as limiting the scope.
1. A luminaire (100, 200, 300, 400, 500) comprising:
a single flexible sheet (110) of reflective material, the flexible sheet being folded
to form a plurality of cavities (111, 112, 11N, 211, 212, 21N, 311, 312, 31N, 411,
412, 41N, 511, 512, 51N); and
a plurality of light emitting elements (121, 122, 12N), each light emitting element
being positioned in a different cavity such that each cavity forms a reflector for
a respective light emitting element.
2. The luminaire (200, 300, 400, 500) of claim 1, wherein the plurality of cavities comprises
at least two cavities having different cross-sectional shapes.
3. The luminaire (200, 300, 400, 500) of claim 2, wherein the plurality of cavities comprises
at least five cavities having different cross-sectional shapes.
4. The luminaire (200, 300, 400, 500) of any of claims 1 to 3, wherein:
each cavity has a width (w) and a depth (d);
the width of each respective cavity is measured at a base of the respective cavity;
and
at least one of the following:
- the plurality of cavities comprises cavities (211, 212, 21N, 311, 312, 31N, 411,
412, 41N) of at least two different depths and/or widths; and/or
- for each cavity (511, 512), the width and/or depth of the cavity varies along a
direction in which the respective cavity extends.
5. The luminaire of claim 4, wherein for each cavity (511, 512), the width and/or depth
of the cavity varies along a direction in which the respective cavity extends.
6. The luminaire (200, 300, 400, 500) of claim 4 or 5, wherein:
each cavity has an associated width-depth ratio, being a ratio between the width (w)
and the depth (d) of the cavity; and
the plurality of cavities comprises cavities of at least two different width-depth
ratios.
7. The luminaire (200) of claim 6, wherein:
the plurality of cavities are arranged to lie perpendicularly to a first direction
(x1); and
with increasing distance along the first direction, the width-depth ratio decreases.
8. The luminaire (300) of claim 6, wherein:
the plurality of cavities (311, 312, 31N) are arranged to lie perpendicularly to a
second direction (x2); and
with increasing distance along the second direction until a reference point (350),
of the plurality of cavities, is reached, the width-depth ratio of each cavity increases;
and
with increasing distance from the reference point (350) along the second direction,
the width-depth ratio of each cavity decreases.
9. The luminaire (100) of claim 1, wherein the plurality of cavities comprises only cavities
of a substantially same size and shape.
10. The luminaire (100, 200, 300, 400, 500) of any of claims 1 to 9, wherein each cavity
in the plurality of cavities is an elongate cavity.
11. The luminaire (100, 200, 300, 400, 500) of any of claims 1 to 10, wherein each of
the plurality of light emitting elements is of a same type.
12. The luminaire (100, 200, 300, 400, 500) of any of claims 1 to 11, wherein each of
the light emitting elements (121, 122, 12N) comprises an elongate light emitting element
positioned in a respective cavity.
13. The luminaire (100, 200, 300, 400, 500) of claim 12, wherein each of the light emitting
elements is either:
at least one discrete LED chip mounted on a single carrier; or
a continuous light emitting band.
14. The luminaire (100, 200, 300, 400, 500) of any of claims 1 to 13, wherein the flexible
sheet (110) comprises or is coated with a white and/or specular material for reflecting
light.
15. The luminaire (100, 200, 300, 400, 500) of any of claims 1 to 14, wherein the flexible
sheet (110) is formed of a wood-derived material, such as paper or cardboard.