Note: Descriptions are shown in the official language in which they were submitted.
CA 02578718 2007-02-14
LUMINAIRE WITH PATTERN GENERATOR
Cross-Reference to Related Applications
[0001] This application claims the benefit of U.S. Application Serial No.
60/773,304,
filed on February 14, 2006, the entirety of which is hereby incorporated by
reference.
Field of the Invention
[0002] This invention relates to luminaires, including but not limited to
illuminated
signs such as emergency exit signs, capable of projecting a pattern, such as a
directional
indicator, to direct building occupants to the nearest exit during a fire or
other emergency.
Background of the Invention
[0003] Luminaires of all kinds, including but not limited to wall sconces,
illuminated
signs, downlights, steplights, and wall packs, are provided in buildings to
illuminate halls,
corridors, offices, and other spaces. Emergency lighting luminaires are
mandated by
commercial building codes throughout most of the world. The most common type
of emergency
lighting luminaire is the exit sign, which is intended to be illuminated at
all times and clearly
direct those in flight to the nearest exit during a fire or other emergency.
Exit signs are typically
placed above doorways or in egress paths to indicate the most efficient manner
of exiting a
building. A simple "EXIT" message can be provided on a sign located directly
above the egress
from the building or, where the egress is located away from the sign, an
"EXIT" message is
normally coupled on the sign with a directional indicator, such as a chevron,
that points toward
the closest exit. In the event of an emergency, it is important that building
occupants be able
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to see the exit sign and its directional indicator to be able to safely exit
the building. Other
luminaires provided in the building illuminate the halls, corridors, etc.
traversed by
occupants to reach such exits during an emergency.
[0004] However, many luminaires are mounted or otherwise located relatively
high
above the ground. For example, exit signs are typically mounted seven to
twelve feet above
the ground in office buildings and similar structures that are occupied by a
large number of
people. However, in the case of some emergencies, such as a fire, smoke could
fill the space
near the ceiling, obscuring the luminaires and making it very difficult, if
not impossible, to
see the directional indicator on the face of exit signs and the path to follow
to reach an exit.
Accordingly, there is a need for a feature in luminaires (and particularly
exit signs) that
provides additional aid to building occupants in locating the nearest exit in
the event that the
luminaires, including the face of the exit signs, are obscured.
Summary of the Invention
[0005] The present invention provides a pattern generator capable of
projecting a
pattern, such as a directional indicator, to enhance the building occupants'
ability to navigate
and find exits during an emergency situation, particularly when visual
conditions are poor.
An exemplary embodiment of a pattern generator includes a light source, a
lens, and a pattern
forming element. In use, the lens directs the light beams emitted from the
light source
toward the pattern forming element, which dictates the projected pattern.
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[0006] The light source, lens, and pattern forming element may be pre-
assembled in a
small housing. While the pattern generator may be installed free-standing, it
is preferably
installed within luminaires. In this way, the pattern generator can emit a
lighted pattern, such
as a directional indicator such as an arrow, on a surface beneath the
luminaire. Incorporation
of the pattern generator into luminaires obviates the need to install the
pattern generators
separately and thus reduces installation cost and time. Moreover, concealing
the pattern
generators within luminaires reduces the number of exposed electrical fixtures
in an
installation and thus enhances aesthetic appeal. Moreover, the pattern
generators can draw
from the power supply of, or within, the luminaire within which it is
installed.
Brief Description of the Drawings
[0007] Figure 1 is a cross-sectional view of one embodiment of the pattern
generator
of this invention.
[0008] Figure 2 is a top plan view of an embodiment of a shape filter of this
invention.
[0009] Figure 3 is a perspective view of an exit sign with an embodiment of a
pattern
generator according to this invention installed therein and projecting a
pattern onto a surface
below the sign.
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Detailed Description of the Drawings
[0010] An embodiment of a pattern generator 10 of this invention is shown in
Figure
1. In this embodiment, a housing 20 includes a light source 22, a lens 24, and
a pattern
forming element 26. Light source 22 is positioned above lens 24, which is
positioned above
pattern forming element 26.
[0011] The housing 20 may be made from any material having suitable structural
integrity, including but not limited to plastic and metal materials. Light
source 22 is powered
by any suitable mechanism (denoted generally by 18) and emits light. The light
source 22
may be a light emitting diode (LED), laser, laser diode (illustrated in Figure
1), or any other
light generation source suitable for inclusion in a luminaire such as an exit
sign. Light
source 22 preferably emits light in an eye-catching color such as red or
green, but can emit
light in any desired color.
[0012] The lens 24 is preferably plastic or glass. The pattern forming element
26 may
be a shape filter 28, such as illustrated in Figure 2. The shape filter 28 may
be formed of a
plastic or metal, although other suitable materials may be used as is well
understood by those
skilled in the art. The shape filter 28 includes an aperture 30 in the shape
of the desired
pattern to be projected. In the illustrated embodiment, aperture 30 is in the
shape of a
directional arrow, but other or multiple shapes may be used and such shapes
may be formed
by one or more apertures in the shape filter 28.
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[0013] In an alternative embodiment, the pattern forming element 26 is a
diffractive
optical element. The diffractive optical element may be plastic or glass and
employs
constructive and destructive interference to manipulate the light into the
desired pattern. The
diffractive optical element may be formed to create the desired pattern using
holographics,
diamond turning, photolithography or e-beam lithography, UV replication, and
hot
embossing, all of which are well known by those of skill in the art.
[0014] In use, the light source 22 generates light beams, and the lens 24
receives the
light beams and directs them toward the pattern forming element 26. If a shape
filter 28 is
used as the pattern forming element 26, the lens preferably focuses the light
beams through
the aperture 30 in shape filter 28. The light passes through aperture 30 and
is projected onto
a surface outside housing 20 in the shape of an arrow 32.
[0015] If a diffractive optical element is used as the pattern forming element
26, the
lens 24 collimates the light beams toward the diffractive optical element
which permits
selective light passage such that a shape (e.g., arrow 32) is projected onto a
surface outside
housing 20. It is preferable that the lens 24 be positioned relative to the
light source 22 so as
not to produce more than approximately 7 divergent light.
[0016] While the pattern forming element 26 is disclosed as forming an arrow
32, one
of skill in the art will understand that the pattern forming element 26 may be
adapted to form
any shape (not just an arrow). Moreover, it need not form a single shape.
Rather, a plurality
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of apertures 30 may be provided in shape filter 28 and a diffractive optical
element provided
so as to create a plurality of shapes when the pattern generator 10 is
activated.
[0017] The housing 20 may be of any shape and the pattern generator 10
components
(light source 22, lens 24, and pattern forming element 26) held within the
housing 20 using
any mechanical retention devices known in the art. All or some of the pattern
generator 10
components may be fixed in position within the housing (for example, via
adhering, welding,
clips, springs, brackets, etc.) or alternatively movably positioned within the
housing 20.
[0018] In one embodiment, the housing 20 is tubular-shaped and has threads 34
on its
inner surface. External threads 36 are provided on the light source 22, lens
24, and/or pattern
forming element 26. The external threads 36 may be formed directly into the
component or
provided in a holder (not shown) in which the component is seated. The
components may be
seated together in a single holder or separately in different holders. In this
embodiment, the
components are secured in housing 20 by engagement of external threads 36 on
the
components (illustrated as formed directly on the components) with internal
threads 34 on
the housing 20. In this way, the components are essentially screwed into the
housing 20 and
the distance between the components within the housing 20 may be adjusted to
vary the size
of the projected image.
[0019] In addition to rotating the entire housing 20, it is conceivable that
the pattern
forming element 26 within the housing 20 can be rotated relative to the
housing 20 to alter
the direction of the arrow 32 that projects onto the surface below. This
allows for selection
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of the orientation of the arrow to be made by the installer at the time of
installation based
upon, for example, the direction of the nearest exit. In some embodiments, the
pattern
generators 10 may be oriented such that the illuminated pattern is displayed
on a wall as
opposed to the floor located beneath the pattern generator. It is also
possible that multiple
light source colors could be used to indicate different exigent circumstances.
In some
embodiments, multiple light sources, lenses, and pattern forming elements may
be used such
that each light source, lens, and pattern forming element combination is
configured to be
activated for a different emergency.
[0020] While the pattern generator 10 disclosed herein could be mounted as a
free-
standing fixture in a building, it is preferably installed within a luminaire.
In this way, the
pattern generator 10 can emit a lighted pattern, such as a directional
indicator such as an arrow,
on a surface beneath or around the luminaire. The pattern generator 10 of the
present invention
may be installed within or used in conjunction with many different types of
luminaires. For
example, certain embodiments of this invention may be used in luminaires such
as those
disclosed in U.S. Patent No. 5,988,825 to Masters et al., entitled "Housing
Frame for Illuminated
Signs Having Multiple Configurations," and U.S. Patent No. 5,797,673 to Logan
et al., entitled
"Emergency Lighting Unit/Exit Sign Combination," each of which is incorporated
herein by
reference in its entirety, or similar exit or emergency lighting fixtures or
housings.
[0021] If the pattern generator 10 is to be installed within a luminaire, the
luminaire
housing needs to have one or more apertures formed in an outer portion thereof
such that the
pattern formed by the pattern generator 10 may be projected outside the
luminaire housing and
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onto a surrounding surface. The apertures could be, but do not have to be,
covered with a clear
material, such as glass or plastic, to shield the luminaire innards from the
surrounding
environment.
[0022] For example, pattern generator 10 may be installed in an exit sign
housing,
such as exit sign housing 12 shown in Figure 3. While the pattern generator 10
is illustrated
and described installed in an exit sign, one of skill in the art will
understand that the pattern
generator 10 may be installed in other luminaires. The pattern generator 10 is
installed
within exit sign housing 12, just above a hole 34 in exit sign housing 12. The
pattern
generator light source 22 can be powered by the exit sign power supply (either
external
power supply or batteries housed within the exit sign). In one embodiment, the
light source
22 is powered by batteries stored within the exit sign housing 12.
[0023] Housing 20, and light source 22, lens 24, and pattern forming element
26
within housing 20, are oriented so that the light emitted from light source 22
is projected
through the pattern forming element 26 and through hole 34 of the exit sign
housing 12 onto
a surface below or surrounding the exit sign in the shape of arrow 32, which
indicates the
direction of the nearest exit in case of an emergency. It is contemplated that
the housing 20
(or the pattern forming element 26) could be rotated external the sign housing
12 to alter the
orientation of the projected pattern. Note that if the pattern generator 10 of
this invention is
installed within a luminaire, it is conceivable that housing 20 could be
eliminated by simply
individually positioning and installing the light source 22, lens 24, and
pattern forming
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element 26 directly in the luminaire housing so that the components interact
as necessary to
project the desired pattern.
(0024) The foregoing description of the exemplary embodiments of the invention
has
been presented only for the purposes of illustration and description and is
not intended to be
exhaustive or to limit the invention to the precise forms disclosed. Many
modifications and
variations are possible in light of the above teaching. The embodiments were
chosen and
described in order to explain the principles of the invention and their
practical application so
as to enable others skilled in the art to utilize the invention and various
embodiments and
with various modifications as are suited to the particular use contemplated.
Alternative
embodiments will become apparent to those skilled in the art to which the
present invention
pertains without departing from its spirit and scope.
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