Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02425474 2003-05-07
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L. l~flch~~l Roherts
~anzada
CA 02425474 2003-05-07
Field of the Invention
The field of the invention relates to "street lights" used to illuminate
highways, parking lots,
residential properties or other areas where large area illumination is
required.
The illumination is provided by means of light deliverance using fiber optic
cable from a re-
motely placed lamp to the top of the pole where there is a lens, diffuser
and/or cover to disperse
the light evenly around an area to be illuminated.
The principal advantage of the invention is that the use of fiber optics
allows the light source,
it's electronics and electrical supply to be remotely mounted in a convenient
location at the base
of the light standard with passive fiber optic and other optical components
used for light deliv-
ery at the top of the light standard [streetlight].
This provides for an economic and more reliable system in the industry with
reduced need for
maintenance. When such maintenance is required, it can easily be performed
from ground level
without the use of ladders, bucket trucks or similar human elevation devices.
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CA 02425474 2003-05-07
Background of the Invention
Street lighting is used widely in public, city, rural, private and commercial
sectors of the light-
ing industry.
The lighting is used mainly in the production of sufficient light levels for
safety and for decora-
tive purposes, supplementing or replacing natural light, at levels suitable
for the human eye to
safely see the environment during hours of darkness.
The spectral characteristics required for human vision can be altered or
enhanced by use of
magnification processes, diffusers or colour filters. The colour spectrum
would be in the visible
spectl-um [420 to 700 nanometers] for the human eye to register the impact of
light so as to
safely see the surroundings.
A variety of street lighting systems are currently in use today. In almost all
cases, high intensity
light is directed or delivered to the lighted area - typically be means of
lamps in fixtures located
at the top of the light standard.
As light systems in the conventional visible spectrum range require high
amounts of electrical
power, a significant gradient in consumption is built up with the uses of
conventional street
lighting. Light sources used in the past are sodium, metal halide and mercury
vapour.
F
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A fiber optics based streetlight places a lens or diffuser on the distal
[output] end of the fiber
optic transmission system to ensure high intensities and maximum rate of
visible light for the
desired coverage area.
Airflow is employed in the cooling of the remote light source. T he airflow is
contained around
the bulb in the lamp-house enclosure, which is vented such that fresh, cool
air can enter, and is
then expelled once heated. Typically cooling fans or convection cooling is
used in the process.
There are many disadvantages of the current technologies available on the
market. The most
dominant criteria is the access to the lamps) for maintenance. Lamps located
at the usual top of
the lamp standard increase operation and maintenance costs over the lifetime
of the streetlight's
use.
The present invention seeks to improve on current systems by means of
providing the ability to:
l/ Locate the light source away from the top of the lamp standard. This is
accomplished by
using fiber optics to deliver the light to the radiating portion of the
fixture.
2/ Use more efficient projection or integral reflector type lamps for energy
savings and then
transmit the light so generated through fiber optic cabling.
3/ Provide heat reduction and longevity of the system. This is achieved by
means of control-
ling the light deliverance to the fiber optics.
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41 Provide even illumination of the desired area by light delivery using fiber
optics and an
optical system andlor diffuser located at the top of the pole.
5/ Locate the lamp remotely from the illuminated area and conduct or transmit
the light to
the area to be illuminated by means of fiber optics to allow for flexibility
in system configura-
tion.
6/ Allow for the use of color changes in the strcetlight, either dynamically
or statically, for
seasonal or holiday or occasions.
7/ Reduce the costs of ownership and maintenance by remotely locating the
light source such
that it can be changed as needed from ground level without the use o.f
ladders, bucket trucks or
other elevating devices.
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Brief Description of the Drawings
Figurel - A two dimensional drawing of the external view of a streetlight
[numbers in brackets
refer to the numbered items in the drawing] with:
(1) A base to secure the assembly to a pedestal or other solid mounting
surface;
(2) A secured access cover to permit access to the lamp-house for lamp
changes;
(3) A light standard (pole) with internal fiber optic cable;
(4) A photo detector to control automatic operation of the streetlight;
(5) An extension arm to hold the light delivery assembly;
(6) A light delivery assembly;
(7) A cover and/or diffuser for the delivery end of the fiber optic cable;
(8) The area illuminated by the fiber optically delivered light.
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Fib ire
2 - A
drawing
of the
lamp
house
with
light
source
and fiber
optic
cable
affixed
for light
transmission
to the
remote
light
delivery
assembly
[numbers
in brackets
refer
to the
numbered
items
in the
drawing]
with:
(9) Cooling fan;
( 10) Lamp-house body
(11) Electronics
( 12) Lamp connector
(13) Lamp
(14) Reflector
(15) Infrared blocking filter
( 16) Optical system
17) Light trap and ventilation
(18) Filter holder for color changes
( 19) Fiber optic cable connector
(20) Retaining screws
(21 ) Proximal fiber ferrule
(22) Fiber optic cable
(23) Distal fiber ferrule
(24) Distal optical system
(25) Deflector assembly
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Figure 3 - An "x-ray" drawing of the invention showing an embodiment where the
lamp-house,
fiber optic cable, light delivery fixture and associated components are in a
single assembly
which has the appearance of a conventional streetlight assembly [numbers in
brackets refer to
the numbered items in the drawing] with:
(1) Base
(2) Lamp-house access
(3) Light standard [pole
(4) Photo detector
(5) Extension arm
(6) Light delivery assembly
(7) Diffuser/cover
(8) Illuminated area
(9) Cooling fan
(10)Lamp-house body
( Electronics
11
)
( Lamp connector
12)
( Lamp
13
)
( Reflector
14)
(15)Infrared blocking filter
( Optical system
16)
( Light trap and ventilation
17)
(18)Filter holder to permit
colour changes
(19)Fiber optic cable connector
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(20) Retaining screws
(21) Proximal fiber ferrule
(22) Fiber optic cable
(23) Distal fiber ferrule
(24) Distal optical system
(25) Deflector assembly
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Detailed Description of the Invention
In order to more clearly understand the present invention part numbers are
assigned as
follows:
Part Number I)escraptl~n
1) Base
2) Lamp-house access
3) Light standard [pole]
4) Photo detector
5) Extension arm
6) Light delivery assembly
7) Diffusericover
8) Illuminated area
9) Cooling fan
10) Lamp-house body
11) Electronics
12) Lamp connector
13 ) Lamp
14) Reflector
15) Infrared blocking filter
1 G) Optical system
17) Light trap & ventilation
18) Filter holder
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19) Fiber optic cable connector
20) Retaining screws
21 ) Proximal fiber ferrule
22) Fiber optic cable
23) Distal fiber ferrule
24) Distal optical
system
25) Deflector assembly.
The lighting system compromises an improved light source for illuminating
optical
fibers in the visible light spectrum including, a high intensity gas discharge
[or other] lamp posi
boned within a reflector assembly that focuses visible radiation from the lamp
into the fiber op-
tic medium at a focal point that selectively transmits visible light and
attenuates the ultra-violet
and infra-red radiation.
The alignment procedures and the geometry of the reflector design ensure
maximum in-
tensity supplied to the fiber optics positioned at the focal point of the
assembly.
The bulbs are formed in a glass blank that supports the electrode and the lead
in conduc-
tons that are housed for the electrodes in a fixed relationship. The bulb and
the blank with the
lead-in connectors pass through the envelope to form the connector pins. Lamps
are currently
available with this type of configuration.
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Lamps typically include a reflector substantially axially and symmetrically
disposed
about the lamp. The lamp may be symmetrically orientated about the horizontal
and vertical
axis for the purpose of concentrating the illumination intensity of the lamp.
The reflector includes an alignment section arid a mounting section .The
reflector is de-
signed to focus the light from a filament or a gas discharge arc, which is
maintained between
electrodes by use of conventional external circuitry, into the desired area.
Light is focused in a relatively small focal area such that the ends of the
optical fibers
are located within the focus. Reflector design is of ellipsoidal shape of
revolution about the ori-
gin axis which lay the foci of the Lamp. The ellipsoidal reflector nay
optimized for different
bulb types and shapes.
At certain times mercury vapour lights provide an optimum spectrum of light
for street
lighting applications. They optimize in th.e blue wavelengths and are
effective in daylight simu-
lation. Sodium lamps are also used and produce a reddish Light to optimize
seen features on a
pathway or enclosed area. Typically high-pressure lights have the highest
efficiency providing
one hundred to one hundred plus .lumens per watt. :Metal-halide or mercury
vapour lamps pro-
vide the best lighting alternative of natural light at a cost efficiency.
In the present invention, the means for transmitting light is fiber optic
cable. This is
shown in Figure 3. Fiber optic cable means that optical fibers are gathered
together in one bun-
dle or conductor. There may be, for example, several hundred fibers in such a
cable or in glass
CA 02425474 2003-05-07
cable incozporating several thousand fibers. The fiber optic cable bundle is
terminated at the
light delivery end of the fiber by grouping the fibers together into a metal
fixture then cleaning
or polishing the end fittings [ferrules.
Each fiber must be located and optimized for efficient light transmission to
the distal
end of the fiber optic cable. The method of achievW g this is by means of a
lens or other optical
structure to focus the available light into the proximal end of the fiber
optic cable. A holder or
fitting secures the optical fibers in their ferrule at the proximal end.
The light transmitted through the fiber optic cable is focused or diffused as
needed by an
optical system which may contain lenses, reflectors or diffusers such that the
light is projected
into the area where illumination is desired. A holder or fitting secures the
optical fibers in their
ferrule at the distal end.
It will be understood that modifications can be made in the embodiments of the
invention de-
scribed herein.
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CA 02425474 2003-05-07
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It is an object of the invention that it provides a light source. with optimal
characteristics for
JtI~:'.e~ light117g;
It is a further object of the invention that it provides a means for focusing
light from said light
sovzrce into a fibre optic traz;amission medium;
It is a fuz-ther object of the invention that it incorporates a fibre optic
cable for transmitting the
light tom said light sc:zrce :o a distribution means:
It is a fuz-ther ob,~ect of the invention that it provides for a fza.tttre
containing a lens andlor dif
fuser to distribute the light over a specified area.
In accordance with the present in'~ention, a lighting system is deseribe-d
comprising a
projection light to simulate daylight conditions.Pro~~idina daylight
simulation by ways of focus-
ing the light into a fibre optic $raIlSI?llSSlon Illedl!ltn Of dual or single
mode transmission.
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