CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority from Italian patent application no.
102018000010257 filed on 12/11/2018.
TECHNICAL FIELD
[0002] The present invention relates to a light source assembly and to a light fixture comprising
said light source assembly. Preferably, the light fixture is a stage light fixture.
BACKGROUND ART
[0003] In recent years, in the entertainment sector, there has been a significant increase
in the use of light fixtures with solid state light sources (Solid State Lighting),
such as LEDs.
[0004] Solid state light sources are associated with electronic components that can become
a significant source of acoustic noise, especially when they are adjusted by pulse
width modulation commands. The electromagnetic force induced on these components by
the PWM modulation, in fact, determines a vibration of the components, which causes
audible acoustic noise. The generated acoustic noise has a dominant component at the
same frequency as the PWM modulation or its harmonics.
[0005] Currently, some solutions plan to increase the PWM modulation frequency above the
audible frequency level. This means increasing the PWM modulation frequency above
16 KHz. The use of modulation at such high frequencies leads to a reduction in the
resolution of the modulation with obvious negative consequences in terms of colour
stability and brightness of the light beam.
DISCLOSURE OF INVENTION
[0006] It is therefore an object of the present invention to provide a light source assembly
that is free from the drawbacks of the known art herein disclosed. In particular,
an object of the invention is to provide a light source assembly in which the acoustic
noise is significantly reduced and which, at the same time, emits a high quality light
beam.
[0007] In accordance with these objects, the present invention relates to a light source
assembly comprising:
at least one solid state light source configured to emit one or more light beams along
an emitting direction;
at least one reflector assembly associated with the light source;
at least one optical element arranged downstream of the reflector assembly along the
emitting direction;
at least one acoustic barrier element arranged between the optical element and the
reflector assembly.
[0008] Advantageously, the light source assembly according to the present invention is noiseless
with respect to the source assemblies of the known art.
[0009] The presence of the acoustic barrier element, in fact, significantly reduces the
audible noise level outside the light source assembly.
[0010] According to a preferred embodiment, the acoustic barrier element and the optical
element are made in a single piece. In this way, the assembling of the light source
assembly is simplified and speeded up.
[0011] According to a variant, the acoustic barrier element and the optical element are
distinct pieces.
[0012] According to a preferred embodiment, the acoustic barrier element is air-permeable.
In this way, the air circulates inside the chamber housing the light source. This
avoids the onset of pressure imbalances due to temperature changes caused by the presence
of at least one light source. According to a preferred embodiment, the acoustic barrier
element is made of a polymeric material.
[0013] According to a preferred embodiment, the acoustic barrier element is made of a material
having a hardness below 100 on the Shore OO hardness scale. In this way, the acoustic
barrier element has a level of compressibility that is sufficient to guarantee a correct
acoustic noise reduction effect.
[0014] According to a preferred embodiment, the acoustic barrier element is made of a silicone
material.
[0015] According to a preferred embodiment, the reflector assembly comprises a reflector
element and at least one support body configured to support the reflector element.
[0016] According to a preferred embodiment, the light source assembly comprises at least
one clamping device configured to clamp the acoustic barrier element against a support
surface. This further optimizes the acoustic noise isolation level.
[0017] According to a preferred embodiment, the light source assembly comprises at least
one support plate to support the light source, wherein the support body is fixed to
the support plate. This guarantees the stability of the reflector assembly.
[0018] According to a preferred embodiment, the light source assembly comprises at least
one further acoustic barrier element arranged between the support plate and the support
body. This further optimizes the acoustic noise isolation level.
[0019] According to a preferred embodiment, the further acoustic barrier element is air-permeable.
In this way, even the further acoustic barrier element ensures a correct air circulation
to avoid the onset of any pressure unbalance.
[0020] A further object of the invention is to provide a light fixture in which the acoustic
noise is significantly reduced and which is capable of projecting high quality light
beams.
[0021] In accordance with these objects, the present invention relates to a light fixture
comprising a casing and at least one light source assembly of the type described above,
which is housed inside the casing and is configured to generate a light beam along
at least one optical axis. The light fixture is provided with at least one output
optical assembly arranged inside the casing or closing the casing downstream of the
light source assembly along the optical axis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Further characteristics and advantages of the present invention will appear clear
from the following description of a non-limiting embodiment thereof, with reference
to the figures of the annexed drawings, in which:
- Figure 1 is a schematic side view, with parts in section and parts removed for clarity's
sake, of a light fixture according to the present invention;
- Figure 2 is a perspective side view, with parts in section and parts removed for clarity's
sake, of a light source assembly according to a first embodiment of the present invention;
- Figure 3 is a perspective side view, with parts in section and parts removed for clarity's
sake, of a light source assembly according to a second embodiment of the present invention;
- Figure 4 is a perspective side view, with parts in section and parts removed for clarity's
sake, of a light source assembly according to a third embodiment of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0023] In Figure 1 the reference number 1 indicates a light fixture, preferably a stage
light fixture.
[0024] The light fixture 1 comprises a casing 2 and support means (not shown in the attached
figures) configured to support the casing 2. Preferably, the support means are configured
to move the casing 2 and to allow the casing 2 to rotate about two orthogonal axes,
commonly known as PAN and TILT. The operation of the support means is regulated by
a movement control device (not visible in the attached figures). The movement control
device can also be managed remotely, preferably via DMX protocol communications. According
to a variant, the support means can be configured to support only the casing 2 without
allowing it to be moved.
[0025] The casing 2 extends along a longitudinal axis A and is provided with a first closed
end 4 and with a second end 5, opposite to the first closed end 4 along the axis A
and provided with a projection mouth 6. In the non-limiting example herein described
and shown, the projection mouth 6 has a substantially circular section. Preferably,
the projection mouth 6 is centred on the axis A of the casing 2.
[0026] The light fixture 1 further comprises a frame (not visible in the attached figures)
coupled to the casing 2, at least one light source assembly 7 supported by the frame
and arranged near the first closed end 4, and at least one output optical assembly
9.
[0027] The light source assembly 7 is configured to generate a light beam along an optical
axis B. In the non-limiting example herein described and shown, the optical axis B
coincides with the longitudinal axis A.
[0028] A not shown variant provides that the light fixture 1 comprises a plurality of light
source assemblies, preferably side by side on the same plane orthogonal to the axis
A. Each light source assembly is configured to generate a respective light beam along
a respective optical axis.
[0029] The output optical assembly 9 is arranged downstream of the light source assembly
7 along the respective optical axis B.
[0030] According to a not shown variant, the light fixture 1 can further comprise one or
more optical assemblies and/or one or more colour assemblies and/or one or more beam
processing groups, preferably arranged downstream of the respective light source assembly
along the respective optical axis.
[0031] With reference to Figure 2, the light source assembly 7 comprises at least one solid
state light source 10 configured to emit one or more light beams along an emitting
direction D, at least one reflector assembly 11 associated with the light source 10,
at least one optical element 12 arranged downstream of the reflector assembly 11 and
at least one acoustic barrier element 13 arranged between the optical element 12 and
the reflector assembly 11 so as to provide a chamber 15 to isolate the acoustic noise.
[0032] In the non-limiting example herein described and shown, the light source assembly
7 comprises a plurality of solid state light sources 10, preferably of the LED type.
[0033] The light sources 10 are integrated in a chip coupled to a printed circuit board
16. The chip is connected to contact pads on the printed circuit board 16 via wire
bonding, not shown in the attached figures for simplicity's sake.
[0034] The printed circuit board 16 is supported by a support plate 18.
[0035] Preferably, the light sources 10 together define an emission surface of the light
beams that can have a cross-section having a circular, square, elliptical, hexagonal,
polygonal or any other shape.
[0036] The reflector assembly 11 comprises a reflector element 19 and a support body 20.
[0037] The reflector element 19 is configured to reflect the light beam emitted by each
light source 10 and direct it towards an outlet opening 23 of the reflector element
19. Preferably, the outlet opening 23 has a circular shape. Preferably, the reflector
element 19 is further provided with an inlet opening 22, opposite to the inlet opening
22 along the emitting direction D.
[0038] In particular, the reflector element 19 is arranged with respect to the light source
10 so that the light beam emitted by each light source 10 first crosses the inlet
opening 22 and then the outlet opening 23.
[0039] In other words, the reflector element 19 is arranged so that the outlet opening 23
is downstream of the inlet opening 22 along the emitting direction D.
[0040] Preferably, the light sources 10 are arranged substantially at the inlet opening
22.
[0041] Preferably, the inlet opening 22 is shaped so as to collect as many light beams as
possible.
[0042] In particular, the inlet opening 22 defines an inlet passage, which has an area at
least equal to the area of the emission surface defined by the light sources 10. More
specifically, the area of the inlet passage is greater than the area of the emission
surface defined by the light sources 10.
[0043] Preferably, the inlet opening 22 is shaped so as to substantially surround the light
sources 10.
[0044] Preferably, the shape of the section of the inlet passage of the inlet opening 22
is chosen according to the shape of the emission surface defined by the light sources
10, which for example can have a circular, square, elliptical, hexagonal, polygonal
or any other shape.
[0045] Preferably, the outlet opening 23 has a greater passage section than the passage
section of the inlet opening 22. In the non-limiting example herein described and
shown, the reflector element 19 is substantially defined by a main body 24, preferably
having the shape of a truncated cone. In the non-limiting example herein described
and shown, the outlet opening 23 is provided with an annular edge 26, which extends
from the main body 24.
[0046] The main body 24 is provided with an inner surface 27, which has at least one active
portion.
[0047] The active portion is configured to reflect the inlet light beams and direct them
towards the outlet opening 23. In the non-limiting example herein described and shown,
the active portion extends over the entire inner surface 27.
[0048] The reflector element 19 can be made of a metallic material (e.g. aluminium or silver)
or of a polymeric material (e.g. PET or PMMA).
[0049] The support body 20 is configured to support the reflector element 19.
[0050] In particular, the support body 20 is configured to support the reflector element
19 so that the reflector element 19 is arranged downstream of the light source 10
along the emitting direction D.
[0051] More preferably, the reflector element 19 is supported by the support body 20 so
as to be spaced from the printed circuit board 16. In this way, any contact with conductive
portions of the printed circuit board 16 and/or of the light sources 10 is avoided.
[0052] The support body 20 is fixed to the support plate 18, for example by means of screws
28 (partially visible in Figure 2) .
[0053] The support body 20 is substantially cylindrical and extends along an axis C about
the reflector element 19.
[0054] The support body 20 is provided with a first end 30 fixed to the support plate 18
and with a second end 31 to which the reflector element 19 is coupled.
[0055] In particular, at the second end 31, the support body 20 is provided with a preferably
threaded outer edge 32 and with an inner edge 33, which defines an annular coupling
surface 34. Preferably, the annular coupling surface 34 is orthogonal to the axis
C of the support body 20. The outer edge 32 protrudes from the outer side surface
of the support body 20 and preferably has an L-shaped section. The outer edge 32 and
the inner edge 33 substantially define an inner annular seat 35, which, as shown in
greater detail below, houses a portion of the reflector element 19, a portion of the
acoustic barrier element 13 and at least a portion of the optical element 12.
[0056] In the non-limiting example herein described and shown, the annular edge 26 of the
reflector element 19 is arranged to rest on the annular coupling surface 34.
[0057] A further acoustic barrier element 36 is preferably arranged between the support
plate 18 and the support body 20.
[0058] As shown in more detail later, the further acoustic barrier element 36 is preferably
made with a material having characteristics similar to those of the material constituting
the acoustic barrier element 13.
[0059] Preferably, the reflector element 19 and the support body 20 are coaxially arranged.
Preferably, also the light sources 10 are centred on the axis C. In the specific non-limiting
example herein described and shown, the printed circuit board 16 is centred on the
axis C of the support body 20.
[0060] The optical element 12 is arranged downstream of the reflector assembly 11 and is
also preferably centred on the axis C.
[0061] The optical element 12 is configured to modify the direction of at least a portion
of the light rays that make up the beam emitted by one or more light sources 10.
[0062] In the example of Figure 2, the optical element 12 is a condenser element and comprises
one or more optical devices arranged and configured so that the inlet beam is concentrated
in a desired manner. In the non-limiting example herein described and shown, the optical
element comprises a lens configured to concentrate the beam at a given point (called
focus point). In the non-limiting example herein described and shown the lens is a
plano-convex lens. In this way, the light beam leaving the optical element 12 is a
beam having an optical axis B.
[0063] The acoustic barrier element 13 is arranged between the optical element 12 and the
reflector assembly 11 and is configured to attenuate the audible noise produced by
the light sources 10 and by the electronic components associated with them.
[0064] Preferably, the acoustic barrier element 13 is arranged between the optical element
12 and the reflector assembly 11 and is configured to attenuate the noise produced
by the light sources 10 and by the associated electronic components of at least 5
dB, preferably of at least 10 dB.
[0065] In particular, the acoustic barrier element 13 is annular and is preferably arranged
resting on the annular edge 26 of the reflector element 19.
[0066] A not shown variant provides that the acoustic barrier element 13 is arranged to
rest on the annular coupling surface 34 without contact with the reflector element
19. This solution is particularly useful in applications where it is desired to avoid
any contact between the reflector element 19 and the acoustic barrier element 13 to
keep them at different temperatures.
[0067] The acoustic barrier element 13 is preferably air-permeable, e.g. made of an air-permeable
material. The air circulation in the chamber 15, in fact, avoids the onset of pressure
imbalances due to temperature changes during the activation, operation and deactivation
of the light sources 10.
[0068] Preferably, the acoustic barrier element 13 is made of a compressible material.
[0069] In particular, the acoustic barrier element 13 is made of a material having a hardness
below 100 on the Shore OO hardness scale, preferably in the range 80-90.
[0070] Preferably, the acoustic barrier element 13 is made of a polymeric material that
does not release hydrocarbons when subjected to thermal cycles caused by the activation/operation/deactivation
of the light sources 10.
[0071] In the non-limiting example herein described and shown, the acoustic barrier element
is made of a silicone material.
[0072] A not shown variant provides that the acoustic barrier element is configured so that
the noise is dissipated inside it, e.g. by means of one or more bodies, provided with
at least one surface with a high acoustic transparency facing the chamber 15 and defined
by a filler with porosities arranged in a different direction from the one of the
flow so as to have a high resistance to the flow. In this way, the sound wave penetrates
easily and is therefore dissipated inside.
[0073] A further not shown variant provides that the acoustic barrier element comprises
one or more bodies provided with calibrated resonant cavities communicating with the
chamber 15 by means of respective calibrated necks/holes.
[0074] The light source assembly 7 further comprises at least one clamping device 39 configured
to clamp the acoustic barrier element 13 against a support surface.
[0075] In the non-limiting example of Figure 2, the clamping device 39 clamps the acoustic
barrier element 13 against the annular edge 26 of the reflector element 19. According
to a not shown variant, the clamping device 39 clamps the acoustic barrier element
13 against the annular coupling surface 34 of the support body 20.
[0076] In the non-limiting example herein described and shown, the clamping device 39 is
an annular ring nut 40, which is internally threaded to cooperate with the outer edge
32 of the support body 20 of the reflector assembly 11. The annular ring nut 40 is
arranged on the perimeter edge of the optical element 12.
[0077] According to a not shown variant, the annular ring nut 40 is made of a material that
is optically transparent to the radiations in the visible range.
[0078] In use, the annular ring 40 is screwed onto the outer edge 32 of the support body
20. The screwing of the annular ring 40 causes the clamping of the acoustic barrier
element 13 against the annular edge 26. In the non-limiting example herein described
and shown, the acoustic barrier element 13 is clamped between the optical element
12 and the annular edge 26 of the reflector assembly 11. It is clear that the clamping
device can be made in an alternative way, for example by means of clamping devices
of various types.
[0079] The clamping device 39 is configured to clamp the acoustic barrier element 13 so
as to minimize the space between the acoustic barrier element 13 and the surfaces
in contact therewith. Preferably, the space between the acoustic barrier element 13
and the surfaces in contact with it is less than 1 mm.
[0080] The light source assembly 7 thus obtained defines, as already anticipated, a chamber
15 for isolating the acoustic noise. The light sources 10, the reflector assembly
11, the optical element 12 and the acoustic barrier element 13, in fact, define the
chamber 15.
[0081] In particular, the audible noise associated with the light sources 10 does not escape
from the chamber 15. This is mainly due to the particular arrangement of the elements
that make up the light source assembly 7 and to the presence of the acoustic barrier
element 13 arranged between the optical element 13 and the reflector assembly 11.
[0082] Moreover, the clamping device 39 further improves the soundproofing properties thanks
to the clamping of the acoustic barrier element against the adjacent elements. Finally,
the further acoustic barrier element 36 further optimizes the soundproofing properties,
thus contributing to the closure of the chamber 15.
[0083] The further acoustic barrier element 36 is preferably air-permeable, for example
made of an air-permeable material. Preferably, the further acoustic barrier element
36 is made of a compressible material.
[0084] In particular, the further acoustic barrier element 36 is made of a material having
a hardness below 100 in the Shore OO hardness scale, preferably in the range 80-90.
Preferably, the further acoustic barrier element 36 is made of a polymeric material,
which does not release hydrocarbons when subjected to the thermal cycles caused by
the activation/operation/deactivation of the light sources 10.
[0085] In the non-limiting example herein described and shown, the further acoustic barrier
element 36 is made of a silicone material.
[0086] Figure 3 shows a light source assembly 7 according to a variant of the present invention
in which the acoustic barrier element 13 and the optical element 12 are made in a
single piece 50.
[0087] Preferably, the acoustic barrier element 13 is optically transparent to the radiations
in the visible range. Preferably, the acoustic barrier element 13 and the optical
element 12 are made in a single piece 50 made of a polymeric material. The single
piece 50 can be made of a material comprising a single mixture of polymeric material
or it can comprise at least a first central area made of a material having a first
mixture of polymeric material and at least a second peripheral area made of a material
comprising a second mixture of polymeric material different from the first mixture
of polymeric material. Preferably, the first central area will be made of a material
having the required optical properties (e.g. silicone enriched with ceramic powder),
while the second peripheral area will be made of a material which is air-permeable
and, for example, also compressible.
[0088] Figure 4 shows a light source assembly 7 in accordance with a further variant of
the present invention, in which the optical element 12 comprises a diffuser element
51 and a condenser element 52, which are mutually spaced apart by an annular spacer
element 53. The condenser element 52 and the acoustic barrier element 13 are made
in a single piece 50. Also in this case the acoustic barrier element 13 is preferably
optically transparent to the radiations in the visible range.
[0089] In this case, the clamping device 39 clamps the acoustic barrier element 13 against
a support surface 54 of the annular spacer 53.
[0090] The diffuser element 51 is preferably a monolithic element. A not shown variant provides
that the mixer comprises a plurality of mixing devices arranged next to each other
and substantially aligned with the respective light sources 10. The condenser element
52 is arranged downstream of the diffuser element 51 along the emitting direction
D and comprises one or more optical devices arranged and configured so that the inlet
beam is concentrated in a desired manner. In the non-limiting example herein described
and shown, the condenser element 52 comprises a lens configured to concentrate the
beam at a given point (called the focus point). In the non-limiting example herein
described and shown the lens is a plano-convex lens. A not shown variant provides
that the condenser element 52 is defined by a group of coupled lenses.
[0091] Substantially, the light beam leaving the optical element 12 is mixed, homogeneous
and condensed. In this way, the light beam leaving the optical element 12 is a beam
having an optical axis B.
[0092] According to a variant not shown in the present invention, the acoustic barrier element
is provided with an annular groove, which is engaged by an annular portion of the
reflector assembly or of the spacer element.
[0093] Finally, it is clear that modifications and variations may be made to the light source
assembly and to the light fixture described herein without departing from the scope
of the appended claims.
1. Light source assembly (7) comprising:
at least one solid state light source (10) configured to emit one or more light beams
along an emitting direction (D) ;
at least one reflector assembly (11) associated to the light source (10);
at least one optical element (12) arranged downstream of the reflector assembly (11)
along the emitting direction (D) ;
at least one acoustic barrier element (13) arranged between the optical element (12)
and the reflector assembly (11) .
2. Light source assembly according to claim 1, wherein the acoustic barrier element (13)
and the optical element (12) are made in a single piece (50).
3. Light source assembly according to claim 1, wherein the acoustic barrier element (13)
and the optical element (12) are made in separate pieces.
4. Light source assembly according to any one of the preceding claims, wherein the acoustic
barrier element (13) is air-permeable.
5. Light source assembly according to any one of the preceding claims, wherein the acoustic
barrier element (13) is made of a polymeric material.
6. Light source assembly according to any one of the preceding claims, wherein the acoustic
barrier element (13) is made of a material having a Shore lower than 100 in the Shore
00 scale.
7. Light source assembly according to any one of the preceding claims, wherein the acoustic
barrier element (13) is optically transparent at least to radiations in the visible
range.
8. Light source assembly according to any one of the preceding claims, wherein the acoustic
barrier element (13) is made of a silicone material.
9. Light source assembly according to any one of the preceding claims, wherein the reflector
assembly (11) comprises a reflector element (19) and at least one support body (20)
configured to support the reflector element (19).
10. Light source assembly according to claim 9, comprising at least one clamping device
(39) configured to clamp the acoustic barrier element (13) against a support surface
(26; 34; 53).
11. Assembly according to claim 9 or 10, comprising at least one printed circuit board
(16), the light source (10) being integrated into a chip coupled to the printed circuit
board (16).
12. Assembly according to any one of the claims from 9 to 11, comprising at least one
support plate (18) to support the light source (10); the support body (20) being fixed
to the support plate (18).
13. Assembly according to claim 12, comprising at least one further acoustic barrier element
(36) arranged between the support plate (18) and the support body (20).
14. Assembly according to claim 13, wherein the further acoustic barrier element (36)
is air-permeable.
15. Light fixture comprising a casing (2) and at least one light source assembly (7) according
to any one of the preceding claims, which is housed inside the casing (2) and is configured
to emit a light beam along at least an optical axis (B), the light fixture being provided
with at least one output optical assembly (9) arranged inside the casing (2) or arranged
so as to close the casing (2) downstream of the light source assembly (7) along the
optical axis (B).