U.S. patent application number 11/379999 was filed with the patent office on 2007-10-25 for lighted display case with remote light source.
Invention is credited to Roger F. II Buelow, William J. Cassarly, Robert H. Caywood, John M. Davenport, Thomas L.R. Davenport, Gregory P. Frankiewicz, Chris H. Jenson.
Application Number | 20070247835 11/379999 |
Document ID | / |
Family ID | 38619298 |
Filed Date | 2007-10-25 |
United States Patent
Application |
20070247835 |
Kind Code |
A1 |
Buelow; Roger F. II ; et
al. |
October 25, 2007 |
Lighted Display Case with Remote Light Source
Abstract
Lighted display case with remote light source comprises a
container having contents for display. A solid fiber optic
luminaire is at least partially mounted within the container,
having an elongated side-light emitting portion for emitting light
from the side of the luminaire onto contents in an interior of the
display case. The side-light emitting portion comprises an
extractor of light arranged to preferentially extract light from
the luminaire and direct the light to at least one target area of
said contents. The portion may be rotatable about its own
longitudinal axis. A single side-light emitting portion may be
arranged to illuminate a target area on one of its lateral sides,
and another target area on another lateral side. A single lamp may
provide light to first and second luminaires arranged to illuminate
a target area on one of its lateral sides, and another target area
on another lateral side.
Inventors: |
Buelow; Roger F. II; (Gates
Mills, OH) ; Davenport; John M.; (Middleburg Heights,
OH) ; Cassarly; William J.; (Wooster, OH) ;
Davenport; Thomas L.R.; (Tucson, AZ) ; Frankiewicz;
Gregory P.; (Mayfield Heights, OH) ; Jenson; Chris
H.; (Twinsburg, OH) ; Caywood; Robert H.;
(Vermillion, OH) |
Correspondence
Address: |
BRUZGA & ASSOCIATES
11 BROADWAY, SUITE 715
NEW YORK
NY
10004
US
|
Family ID: |
38619298 |
Appl. No.: |
11/379999 |
Filed: |
April 24, 2006 |
Current U.S.
Class: |
362/125 |
Current CPC
Class: |
A47F 3/001 20130101 |
Class at
Publication: |
362/125 |
International
Class: |
A47F 11/10 20060101
A47F011/10 |
Claims
1. A lighted display case with remote light source, comprising: a)
a container having contents for display; b) a solid fiber optic
luminaire at least partially mounted within the container; the
luminaire having an elongated side-light emitting portion for
emitting light from the side of the luminaire onto contents in an
interior of the display case; the side-light emitting portion
comprising an extractor of light arranged to preferentially extract
light from the luminaire and direct said light in at least one
radial direction along the length of the side-light emitting
portion to at least one target area of said contents along a
longitudinal axis of the side-light emitting portion; c) the
extractor of light comprising first and second light-extraction
regions; d) the container having a first and second view ports
intended to allow persons outside the container to view contents
displayed in the interior of the container; the first view port
being on one lateral side of the side-light emitting portion and
the second view port being on a second lateral side of said
portion; e) a light-delivery system for providing light to the
fiber optic luminaire; the light-delivery system having a light
source mounted remotely from the container; f) the luminaire being
arranged to illuminate first and second separate target areas of
said contents of the display case; the first target area being
visible through the first view port and the second target area
being visible through the second view port; the first and second
target being illuminated by the first and second light-extraction
regions; and g) the first and second light-extraction regions being
spaced from each other around a perimeter of the side-light
emitting portion taken orthogonally to main optical axis of said
side-light emitting portion.
2. The lighted display case of claim 1, wherein: a) the container
is open to its ambient; and b) the interior of the container is
maintained within 5 C of the temperature of the ambient.
3. The display case of claim 1, wherein: a) the view ports having a
maximum dimension; and b) the side-light emitting portion of the
luminaire extends across the majority of said maximum
dimension.
4. The display case of claim 1, wherein the lamp comprises an HID
lamp.
5. The display case of claim 1, wherein the extractor of light is
arranged to preferentially remove light along the length of the
side-light emitting portion in a plurality of radial directions
along said longitudinal axis.
6. The display case of claim 1, wherein the container contains a
structural member parallel to orthogonal plane of the view port to
block the view of the luminaire inside the case to persons viewing
the contents of the case along a plane intersecting the full
side-light emitting portion and being orthogonal to the view
port.
7. The display case of claim 1, wherein peak illuminance on the
first and second target areas lying in a plane within the case,
parallel to the view ports, is at least 50 percent greater than
peak illuminance on a non-target area lying between the target
areas in said plane.
8. The display case of claim 1, wherein: a) the light-extraction
regions are spatially divided in segments along the length with
gaps between the segments; the longitudinal dimension of the gaps
being greater than the radial width of their respective
light-extraction region; b) the majority of said segments are
divided with gaps of at least 20 percent of the longitudinal
dimension of neighboring segment along the length of the
light-extraction regions; and c) the majority of said segments have
gap portion of the adjacent light-extraction region aligned with at
least 20 percent longitudinal dimension of the respective segment
along the length of the light-extraction regions.
9. The display case of claim 1, further comprising a transparent
cover over the majority of the length of the side-light emitting
portion of the luminaire.
10. The display case of claim 9, wherein the transparent cover
comprises a diffuser for reducing glare from the luminaire.
11. The display case of claim 9, wherein the transparent cover
comprises a Fresnel for directing light emitted from the foregoing
portion into a more narrowed beam.
12. A lighted display case with remote light source, comprising: a)
a container having a view port intended to allow persons outside
the container to view contents displayed in the interior of the
container; b) a solid fiber optic luminaire at least partially
mounted within the container; the luminaire having an elongated
side-light emitting portion for emitting light from the side of the
luminaire onto contents in an interior of the display case; the
side-light emitting portion comprising an extractor of light
arranged to preferentially extract light from the luminaire and
direct said light in at least one radial direction along the length
of the side-light emitting portion to at least one target area of
said contents along a longitudinal axis of the side-light emitting
portion; c) the extractor of light comprising first and second
light-extraction regions; d) a light-delivery system for providing
light to the fiber optic luminaire; the light-delivery system
having a light source mounted remotely from the container; and e)
the side-light emitting portion of the luminaire is rotatable about
its own longitudinal axis for directing the aim of light emitted
therefrom to various radial directions about said axis.
13. The display case of claim 12, wherein: a) the view port has a
maximum dimension; and b) the side-light emitting portion of the
luminaire extends across the majority of said maximum
dimension.
14. The display case of claim 12, wherein the container contains a
structural member parallel to orthogonal plane of the view port to
block the view of the luminaire inside the case to persons viewing
the contents of the case along a plane intersecting the full
side-light emitting portion and being orthogonal to the view
port.
15. The display case of claim 12, wherein the case comprising means
for releasably holding the luminaire in any of a plurality of
predetermined positions.
16. The display case of claim 14, wherein the means for releasably
holding comprises a resiliently biased detent mechanism causing
said side-light emitting portion to be releasably held in any of a
plurality of predetermined radial positions.
17. The display case of claim 12, wherein the lamp comprises an HID
lamp.
18. The display case of claim 16, wherein the light-delivery system
includes at least one LED and a non-imaging optic for coupling
light into a fiber optic structure that passes through a wall of
the container.
19. The display case of claim 12, further comprising a transparent
cover over the majority of the length of the side-light emitting
portion of the luminaire.
20. The display case of claim 19, wherein the transparent cover
comprises a diffuser for reducing glare from the luminaire.
21. The display case of claim 19, wherein the transparent cover
comprises a Fresnel for directing light emitted from the foregoing
portion into a more narrowed beam.
22. A lighted display case with remote light source, comprising: a)
a container having contents for display; b) a first and second
solid fiber optic luminaires at least partially mounted within the
container; each luminaire having an elongated side-light emitting
portion for emitting light from the side of the luminaire onto
contents in an interior of the display case; the side-light
emitting portion comprising an extractor of light arranged to
preferentially extract light from the luminaire and direct said
light in at least one radial direction along the length of the
side-light emitting portion to at least one target area of said
contents along a longitudinal axis of the side-light emitting
portion; c) the extractor of light comprising first and second
light-extraction regions; d) the container having a first and
second view ports intended to allow persons outside the container
to view contents displayed in the interior of the container; the
first view port being on one lateral side of the sidelight emitting
portion and the second view port being on a second lateral side of
said portion; e) a light-delivery system having a lamp for
supplying light to the first and second luminaires; f) the
side-light emitting portions of the first and second luminaires
being mounted parallel to each other and being respectively
positioned to illuminate a target area on one side of the
luminaires and a laterally adjacent target area on another side of
the luminaires.
23. The display case of claim 22 wherein: a) the view port has a
maximum dimension; and b) the side-light emitting portion of the
luminaire extends across the majority of said maximum
dimension.
24. The display case of claim 22, wherein the lamp comprises an HID
lamp.
25. The display case of claim 22, wherein the container contains a
structural member parallel to orthogonal plane of the view port to
block the view of the luminaire inside the case to persons viewing
the contents of the case along a plane intersecting the full
side-light emitting portion and being orthogonal to the view
port.
26. The display case of claim 22, further comprising a transparent
cover over the majority of the length of the side-light emitting
portion of the luminaire.
27. The display case of claim 27, wherein the transparent cover
comprises a diffuser for reducing glare from the luminaire.
28. The display case of claim 27, wherein the transparent cover
comprises a Fresnel for directing light emitted from the foregoing
portion into a more narrowed beam.
29. The display case of claim 22, wherein the light-delivery system
includes: a) a collector mounted to the container for coupling
light along a first optical axis that is angled more than 70
degrees from a main optical axis of the first luminaire; and b) a
corner-turning device at both ends of the coupler for turning the
light from the first and the second optical axis to the said main
axis of both said luminaires.
30. The display case of claim 25, wherein the collector comprises a
non-imaging collector for reducing the angular distribution of
light collected from the HID lamp by the foregoing collector.
31. The display case of claim 25, wherein the light-delivery system
includes a first fiber optic structure sufficiently curved to
receive light along the first optical axis and to transmit light
along the main optical axis of the first luminaire that is more
than 70 degrees angled from the first optical axis.
32. The display case of claim 25, wherein the light-delivery system
further comprises a) a second non-imaging collector for reducing
the angular distribution of light collected by the foregoing
collector; and b) a second fiber optic structure sufficiently
curved to receive light from second collector along a respective
main second optical axis and to transmit light along the main
optical axis of the second luminaire that is more than 70 degrees
angled from the second optical axis.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a lighted display case with
a remote light source. More particularly, the invention relates to
such a display case in which light for illuminating contents of the
case is provided by a fiber optic luminaire.
BACKGROUND OF THE INVENTION
[0002] Traditional display cases used to display retail merchandise
or items of value such as in a museum often employ fluorescent or
(filamented) halogen lamps to light the items. Such lamps have
various disadvantages for lighting tightly confined spaces. Among
these is the fact that fluorescent tubes emit light in all
directions and emit moderate levels of ultraviolet light. When
taken together with their ballasts, the complete lighting system
can produce a significant amount of heat, especially when confined
in an enclosure. Halogen or incandescent lamps similarly have the
disadvantages of directing a large amount of heat into the display
area. Although a halogen lamp is often accompanied by a special
dichroic reflector which concentrates visible light but not
infrared light in the forward direction, the confined nature of a
display case often ends up trapping this undirected infrared energy
anyway. This usually results in an excessive heat buildup or the
necessity to remove this heat by energy-demanding means such as air
conditioning or forced air convection. Even when no special
measures are taken to transport the unneeded heat away, the heat is
usually an inconvenience at best and a nuisance at worst to the
customers or patrons who must view the contents of the case.
[0003] The need exists for an energy-efficient way to light the
merchandise or items contained in a display case while not
introducing any harmful ultraviolet or unnecessary infrared energy
into the display area, and to forgo the need to introduce costly
heat-control devices.
[0004] Fluorescent tubes, while more energy-efficient than
tungsten-halogen lamps, have other disadvantages as well. They are
fragile and contain hazardous substances such as mercury and
phosphors. If broken, the glass shards are a severe safety hazard.
Due to the manner in which such tubes must be mounted in the
typical display case, changing the tubes can be an awkward and
labor-intensive operation requiring the careful removal and
reinsertion of a fragile item in a confined space. Tungsten-halogen
lamps, though compact, are numerous when employed in a typical
display case. As a result, they need to be replaced much more
frequently than their fluorescent counterparts resulting in either
an uneven lighting situation when they fail, or a costly manual
maintenance operation to replace the failed lamps with great
promptness.
[0005] The need exists to allow for a convenient way to maintain or
re-lamp a display-case lighting system which does not suffer from
these disadvantages.
BRIEF SUMMARY OF THE INVENTION
[0006] The disclosed invention provides the foregoing benefits and
others such as requiring less electrical power to provide
comparable amounts of light even apart from the maintenance and
energy transport consideration outlined above.
SUMMARY OF THE INVENTION
[0007] In accordance with one form of invention, a lighted display
case with remote light source is presented which comprises a
container having contents for display. A solid fiber optic
luminaire is at least partially mounted within the container. The
luminaire has an elongated side-light emitting portion for emitting
light from the side of the luminaire onto contents in an interior
of the display case. The side-light emitting portion comprises an
extractor of light arranged to preferentially extract light from
the luminaire and direct the light in at least one radial direction
along the length of the side-light emitting portion to at least one
target area of said contents along a longitudinal axis of the
side-light emitting portion. The extractor of the light comprises
first and second light-extraction regions.
[0008] In a first embodiment, the container has first and second
view ports intended to allow persons outside the container to view
contents displayed in the interior of the container. The first view
port is on one lateral side of the side-light emitting portion and
the second view port is on a second lateral side of said portion. A
light-delivery system provides light to the fiber optic luminaire,
having a light source mounted remotely from the container. The
luminaire is arranged to illuminate first and second separate
target areas of said contents of the display case. The first target
area is visible through the first view port and the second target
area is visible through the second view port. The first and second
target areas are illuminated by the first and second
light-extraction regions. The first and second light-extraction
regions are spaced from each other around a perimeter of the
side-light emitting portion taken orthogonally to main optical axis
of said side-light emitting portion.
[0009] In a second embodiment, the lighted display case remote
light source is presented which comprises a container with a view
port intended to allow persons outside the container to view
contents displayed in the interior of the container. The side-light
emitting portion of the luminaire is rotatable about its own
longitudinal axis for directing the aim of the light emitted
therefrom to various radial directions about said axis.
[0010] In the third embodiment, a lighted display case with remote
light source is presented which comprises a container having
contents for display. First and second solid fiber optic luminaires
are at least partially mounted within the container. Side-light
emitting portions of the first and second luminaires are mounted
parallel to each other and are respectively positioned to
illuminate a target area on one side of the luminaires and a
laterally adjacent target area on another side of the
luminaires.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the drawings, like reference numerals refer to like
parts.
[0012] FIG. 1 is a perspective view of a lighted display case,
shown partially cutaway.
[0013] FIGS. 2 and 3 are simplified front views of the display case
of FIG. 1 in reduced size.
[0014] FIG. 4 is a block diagram of refrigeration means for the
interior of the display case of FIG. 1.
[0015] FIG. 5A is a front view of a pair of fiber optic luminaires
and associated parts shown apart from the display case of FIG.
1.
[0016] FIG. 5B is a detail, sectional view taken at Arrows 5B-5B in
FIG. 5A.
[0017] FIG. 5C is an exploded view of the structures shown in FIG.
5A.
[0018] FIG. 5D is an exploded view similar to FIG. 5C but showing a
single fiber optic luminaire and associated parts shown separate
from the display case of FIG. 1.
[0019] FIG. 6 is a sectional view taken at Arrows 6-6 in FIG.
5A.
[0020] FIG. 7 is a vertical cross section of a feed-through and
associated structure of FIG. 5A.
[0021] FIGS. 8A and 8B are cross sections of different types of
luminaires.
[0022] FIG. 9 is a vertical cross section of a feed-through and
associated structure that is alternative to that shown in FIG.
7.
[0023] FIG. 10 is a perspective view a preferred arrangement for
joining fiber optic structures to luminaires, taken at the upper
end of a luminaire.
[0024] FIG. 11 shows a cross section of a pair of luminaires,
together with a transparent cover for the luminaires.
[0025] FIG. 12 is a cross section similar to FIG. 11 but showing a
different type of transparent cover for the luminaires.
[0026] FIG. 13 is a detail view of a modified luminaire and
associated structure taken at Arrows 13-13 in FIG. 1.
[0027] FIG. 14A is a side view of a luminaire.
[0028] FIG. 148 is sectional view of a luminaire such as shown in
FIG. 14A
[0029] FIGS. 14C and 14D are cross sectional views of
luminaires.
[0030] FIGS. 14E-14G are side views of luminaires.
[0031] FIGS. 15A-15B are simplified views of view ports of the
display case of FIG. 1 and associated luminaires.
[0032] FIG. 16 is a detail view of a luminaire and associated
structure taken at Arrows 13-13 in FIG. 1.
[0033] FIG. 17 is a detail view, partially in section, of a
light-delivery system that may replace the feed-through and
associated light-delivery structures shown in FIG. 1.
[0034] FIG. 18 is a detail view, partially in section, of another
light-delivery system that may replace the feed-through and
associated light-delivery structures shown in FIG. 1.
[0035] FIG. 19 is a simplified detail view, partially in section,
of another light-delivery system that may replace the feed-through
and associated light-delivery structures shown in FIG. 1.
[0036] FIG. 20 is a simplified detail view, partially in section
and partially in block diagram form, of another light-delivery
system that may replace the feed-through and associated
light-delivery structures shown in FIG. 1.
[0037] FIG. 21 is a simplified detail view in block diagram form of
another light-delivery system that may replace the feed-through and
associated light-delivery structures shown in FIG. 1.
[0038] FIG. 22 is a simplified detail view of another
light-delivery system that may replace the feed-through and
associated light-delivery structures shown in FIG. 1.
[0039] FIG. 23 is similar to FIG. 22, showing a variation of that
figure.
[0040] FIG. 24 is a simplified detail view, partially in cross
section and partially in block diagram form, of another
light-delivery system that may replace the feed-through and
associated light-delivery structures shown in FIG. 1.
[0041] FIG. 25 is similar to FIG. 24, showing a variation of that
figure.
DETAILED DESCRIPTION OF THE INVENTION
[0042] FIG. 1 shows a display case 10 for illuminating contents of
the case, such as contents 14, 16 and 18. Case 10 includes a closed
container 11 and fiber optic luminaires (not shown) behind
structural members 12a-12d for achieving the foregoing purpose of
illumination. The term "fiber optic" luminaire is intended to cover
an acrylic rod luminaire that receives light directly from a light
source as well as indirectly through a fiber optic cable or other
structure. Preferably, case 10 includes doors 19, 20 and 21 having
respective view ports 19a, 20a and 21a. These view ports preferably
comprises transparent windows, as shown, but could comprise a
doorway when doors 19, 20 or 21 are opened for viewing contents of
the display case. The luminaires extend vertically over dimension
17a, whereas the maximum dimension of a view port (e.g., 19a) is
dimension 17b. As can be seen dimension 17a is at least the
majority of dimension 17b. Rather than including windows 19a, 20a
and 21a on doors, display case 10a of FIG. 2 shows doors 19, 20 and
21 lacking windows; and FIG. 3 shows display case 10b lacking doors
and instead having openings 25a, 25b and 25c allowing access to
contents. As shown in FIG. 1, an illuminator 24 is preferably
mounted atop container 11, with flexible fiber optic cables 26
leading to the luminaires (not shown). A facade 27, shown in
phantom, may shield illuminator 24 and fiber optic cables 26 from
view.
[0043] Referring to FIG. 4, interior 23 of display case 10 (FIG. 1)
is preferably refrigerated to below about 7 C for unfrozen
refrigeration of contents, and below about -7 C for frozen
refrigeration of contents. This may be accomplished by conventional
refrigeration means 22 for cooling interior 23 of display case 10
of FIG. 1.
[0044] FIGS. 5A, 5B, 5C and 6 show fiber optic luminaires 30 and
32. Referring to FIG. 1, such a pair of luminaires may be contained
between doors 19 and 20, or between doors 20 and 21. As shown in
FIG. 5A, left-hand luminaire 30 illuminates a target area (not
shown) to the left of the luminaire, and right-hand luminaire 32
illuminates a target area (not shown) to the right of luminaire 32.
As shown in FIGS. 5C and 6, each luminaire may be provided with
respective reflectors 34 and 36. Such reflectors may be diffuse or
specular. Reflectors 34 and 36 may be separate from each other or
integral to each other. As shown in FIG. 5C, luminaires 30 and 32
may be held in place with upper clamp 38, middle clamp 40 and lower
clamp 42. Clamps 38, 40 and 42 maintain desired lateral positions
of the associated clamped portions of the luminaires. In addition,
lower clamp 42 includes a horizontally inclined plate 42a for
maintaining the vertical positions of the luminaires.
[0045] As best shown in FIG. 5B, the luminaires may be provided
with claddings within the clamps, such as clamp 38. In particular,
FIG. 5B shows a cladding 30b that may surround luminaire 30 within
clamp 38; cladding 30b having a lower refractive index than the
core of the luminaire. Similarly, a cladding 32b may surround
luminaire 32 within clamp 38; cladding 32b having a lower
refractive index than the core of the luminaire. The luminaires may
be provided with similar cladding in their portions held within the
other clamps, such as clamps 40 and 42 shown in FIG. 5A.
[0046] Clamp 44 (FIG. 5A-5C) holds the lower portions of fiber
optic cables 26a and 26b centered respectively above luminaires 30
and 32. As best shown in FIG. 5B, clamp 44 cooperates with sleeves
46a and 46b for aligning the bottom portions of fiber optic cables
26a and 26b. Sleeves 46a and 46b are preferably made of metal, and
additionally serve to prevent kinking of the bottom portions of the
fiber optic cables. As shown in FIG. 5B, cable 26a comprises a core
26c, a cladding 26d of lower refractive index than core 26c and a
protective jacket 26e of PVC or vinyl, for instance. Similarly,
cable 26b comprises a core 26f, a cladding 26g of higher refractive
index material and a protective jacket 26h of PVC or vinyl, for
instance.
[0047] A channel 48 may be conveniently used for mounting the
luminaires in a display case. As shown in FIG. 5C, clamps 38, 40,
42 and 44 may be secured to channel 48, by bolts 50a, which is in
turn secured to a structural member 12b or 12c (FIG. 1) by bolts
50b. The foregoing clamps secure the luminaires and their input
fiber optic cables in position. Reflectors 34 and 36 may be secured
to channel 48 by bolts 50c. Thus, channel 48 may be conveniently
used for mounting the luminaire arrangement within a display case,
either as an original mounting or a retrofit mounting.
[0048] As shown in FIG. 5A, feed-throughs 54a and 54b are used for
feeding fiber optic cables 26a and 26b through the ceiling of
container 11. In particular, these feed-throughs preferably seal
cables 26a and 26b to at least the internal wall 56 of the
container. It is preferred that feed-throughs also seal the cables
to external wall 58 of the container.
[0049] FIG. 5D shows a single luminaire 30 and associated
structures for use in the FIG. 1 display case to the left of door
19 or to the right of door 21--that is, at the left-most or
right-most ends of the display case. Non-specular (diffusive)
reflector 35a and 35b may have a different shape from non-specular
reflectors 34 and 36 of FIG. 5C. Other than the possible use of a
differently shaped reflector and the use of only a single
luminaire, the structures of FIG. 5D are similar to those in FIG.
5C. Of course, single-luminaire clamps 38a, 40a and 42b are used in
FIG. 5D rather than the double-luminaire clamps 38, 40 and 42 in
FIG. 5C. Similarly, a single-cable clamp 44a is used in FIG. 5D
rather than the double-cable clamp 44 in FIG. 5C.
[0050] FIG. 7 shows feed-through 54a for feeding flexible fiber
optic cable 26a through a wall (e.g., ceiling) of container 11.
Feed-though 54a comprises a penetrating member 60 having a
relatively narrow portion 60a passing through internal and external
walls 56 and 58 (and thermal insulation 62 therebetween). This
feed-through further comprises a relatively enlarged portion 60b
with an upwardly (or axially) facing channel 60c for holding an
O-ring 64 or bead of silicone or other sealant material. An
externally threaded portion of relatively narrow portion 60a
threadedly receives a nut 66 with sufficient tension as to compress
O-ring 64 and seal enlarged portion 60b against internal wall 56.
Meanwhile, a conventional compression fitting 68 is used to seal
cable 26a against enlarged portion 60b.
[0051] Luminaires 30 and 32 may preferably comprise solid fiber
optic structures, such as an acrylic polymer rod. FIG. 8A shows a
solid, single-strand luminaire 70, whereas FIG. 8B shows an
alternative single-strand luminaire 72 having a core 72a and lower
refractive index cladding 72b such as a fluoropolymer. Although the
luminaires of FIGS. 8A and 8B are shown with circular cross
sections, high volume (and hence low cost) molding of luminaires
with other cross sections can be carried out. Other cross sections
could impart more directionality out light output to a luminaire
than with a circular cross section.
[0052] FIG. 9 shows a preferred feed-through 76 for feeding through
container 11 a fiber optic structure 78. Fiber optic structure 78
may be a glass or quartz rod used to thermally isolate the heat of
a lamp (and ballast) from the interior of container 11 or from a
thermally sensitive luminaire (not shown) that receives light from
structure 78. Alternatively, fiber optic structure 78 could be an
extension of a luminaire upwardly (in the orientation shown)
through the ceiling of container 11, or a flexible fiber optic
cable that feeds light to a luminaire (not shown) in the interior
of the container.
[0053] Feed-through 76 comprises a central cylindrical penetrating
part 79 ensheathing fiber optic structure 78, upper and lower
compression fittings 80 and 82, and O-rings 81 and 83.
[0054] Compression fitting 80 includes a threaded nut 80a pressing
compressible O-ring 81 into sealed relation against external wall
58 of container 11 and penetrating part 79. Compression fitting 80
further includes a threaded nut 80b for compressing resilient
material 80c into sealed relation against penetrating part 79 and
fiber optic structure 78. Compression fitting 80 cooperates with
compression fitting 82, whose parts 82a, 82b, 82c and O-ring 83
correspond to parts 80a, 80b, 80c and O-ring 81 of compression
fitting 80. In particular, O-rings 81 and 83 become compressed only
when nuts 80a and 82a are rotated until they are sufficiently close
to each other.
[0055] As just described, feed-through 79 seals fiber optic
structure 78 against both internal and external walls 56 and 58 of
the container.
[0056] FIG. 10 shows a pair of luminaires 30 and 32 that are
rotatable about their respective axes. This allows each luminaire
to be rotated as desired for moving the peak illuminance laterally
across contents of the display case of FIG. 1. This is especially
desirable as the contents to be displayed are moved deeper into the
display case or shallower into the case. As the contents are so
moved, the location of the peak illuminance can be shifted so as to
properly illuminate the contents. Preferably, the luminaires will
be releasably held in a desired position. Means for accomplishing
this would include electro-mechanical means for holding the
luminaire in position, frictional means for holding the luminaire
in position, or mechanical means such as the use of a set screw for
holding the luminaire in position.
[0057] More preferably, luminaires will be releasably held in any
of several predetermined positions, such that the luminaires can be
rotated by hand alone into any of such positions. Such releasable
holding can be accomplished as follows. In FIG. 10, luminaire 32 is
shown in phantom, and its description will be omitted since it may
use the same type of arrangement for being rotated as luminaire 30.
As in FIG. 5A, a clamp 44 holds the lower end of fiber optic cable
26a. Cable 26a could be replaced with a glass or quartz rod, for
example. Clamp 44 cooperates with sleeve 46a protecting the lower
end of the cable. A clamp 38a, modified from clamp 38 shown in FIG.
5A, has a resiliently biased arm 90 whose lower portion comprises a
detent 92, which may be shaped in the form of a semi-sphere, for
instance. Detent 92 may be pressed into any of various holes 94
extending outwardly along band 96. In this way, a user can easily
grasp the luminaire and rotate detent 92 into any of holes 94, for
instance, which will be held in such hole by resiliently biased arm
90. However, the user can use manual (hand) force to rotate the
luminaire into another predetermined position, where it will be
releasably held until another manual force again rotates the
luminaire. Typically, holes 94 would be more closely spaced than
shown in FIG. 10.
[0058] FIG. 11 shows luminaires 30 and 32 together with a
transparent cover 100. Transparent cover 100 protects the surface
of the luminaires from soiling or injury. Beneficially, transparent
cover 100 may also comprise, or be associated with, a lens, such as
the Fresnel lens shown. As a Fresnel lens, transparent cover 100
redirects representative light rays 102a and 102b as the rays pass
through the lens, as shown. Such reorientation of the light rays
permits steering of the peak of light distribution deeper or
shallower into the display case as desired. The transparent cover
can additionally act as a light diffuser to minimize direct views
of the luminaire and to soften specular images of the luminaire
that may be seen as reflections in the contents of the display
case.
[0059] Secondary optics, such as a Fresnel lens, becomes especially
valuable when the intensity (lumens/steradian) from a round rod
luminaire is insufficient to achieve a desired target surface
illuminance. This typically occurs when the angle of light hitting
the target surface area is large, which is typical when the freezer
door is wide (e.g., 91 cm) and the distance to the target surface
is small (e.g., 10 cm). The Fresnel lens can increase the intensity
of the light directed toward the target surface and thereby
increase the target surface illuminance. With a round rod
luminaire, the peak intensity occurs when the radial paint stripe
width (e.g., the illustrated radial angle 101 for a light
extractor) is approximately 20 to 30 degrees, so the Fresnel lens
is often used with narrow paint stripes.
[0060] FIG. 12 shows luminaires 30 and 32 with respective
transparent covers 104a and 104b. Transparent covers 104a and 104b
may comprise an optical lens for making the light distribution from
the luminaires, e.g., rays 106a and 106b, more sharply peaked.
[0061] FIGS. 13-14C concern the use of a single luminaire to
illuminate two laterally adjacent target areas, and a problem of
light blocking that might occur in such luminaire.
[0062] FIG. 13 shows a portion of the display case of FIG. 1 with
doors 19 and 20. In a variation from the display case of FIG. 1,
only a single luminaire 119 is mounted on channel 48, which is
secured to structural member 12b. The figure also shows luminaire
119 with light-extraction regions 120 and 121 of the side-light
emitting portion. Light rays (e.g. 123a and 123b) from
light-extraction region 120 illuminate a desired target area 125,
while the light rays (e.g. 122a and 122b) illuminate a laterally
adjacent desired target area 124.
[0063] Using a single luminaire as in FIG. 13 requires more lumens
of light to be supplied to the luminaire than to each of the two
luminaires shown in FIG. 5A, for instance. Typically, a larger
diameter luminaire would be used for the FIG. 13 embodiment.
[0064] FIG. 14A shows a luminaire 110a shows with light-extraction
regions 111a and 112a, arbitrarily shown as cross-hatched. FIG. 14B
shows a luminaire generally designated 110, to refer to luminaire
110a of FIG. 14A, for instance. FIG. 14B also shows a pair of
light-extraction regions generally designated as 111 and 112, to
refer to regions 111a and 112a in FIG. 14A, for instance. The
light-extraction regions 111a and 112a are arranged longitudinally
along the length of the luminaire 110a. As used herein, a single
light-extraction region provides illumination to a single
continuous target area along some part of the length of the
luminaire. In accordance with an aspect of the invention, the light
is extracted from the side-light emitting portion by
light-extraction regions 111a and 112a to illuminate a pair of
respective pair of laterally adjacent target areas (not shown).
[0065] In FIG. 14A, light-extraction regions 111a and 112a are
continuous along the length of the luminaire. The extraction
efficiency within a light-extraction region may be constant within
each region or may vary within the region. Spatial variations in
extraction efficiency are used to adjust the distribution of light
at the target. In many geometries of light-extraction regions 111a
and 112a, light rays (not shown) from one light-extraction regions
are blocked by the other light-extraction region, resulting in
re-scattering or absorption of the light rays that would otherwise
fall on a desired target area. This blockage problem is shown in
FIGS. 14C and 14D in connection with luminaires 126a and 126b.
[0066] In FIG. 14C, luminaire 126a has two adjacent
light-extraction regions 127 and 128 arranged in a manner to
illuminate two separate target areas of the contents of the display
case. Light-extraction means 127 illuminates a target area to its
left, whereas light-extraction region 128 illuminates a target area
to its right. The light-extraction regions 127 and 128 are spaced
from each other around a perimeter of said side-light emitting
portion taken orthogonally to main optical axis of said side-light
emitting portion. In particular light-extraction regions 127 and
128 are spaced from each other at an angle of .alpha. around the
perimeter of the side-light emitting portion. Generally, the light
rays (e.g. 129a and 129b) from the light-extraction region 127
illuminate the desired target area, but a portion of light rays
(e.g. 129c) from the light-extraction means 127 are blocked by the
other light-extraction region 128. These blocked light rays are
re-scattered by the light-extraction means 128 with some
absorption. These re-scattered light rays (not shown) add with the
light rays (not shown) from the light-extraction region 128 to
illuminate the target area to the right of that region. Typically,
the amount of light rays blocked depends upon the angular
separation a between the light-extraction regions 127 and 128. As
the angle .alpha. increases, the amount of blockage of the light
rays tends to increase.
[0067] FIG. 14D shows a luminaire 126b with a single
light-extraction region 130. The light-extraction region 130
illuminates a desired target area of the contents of the display
case with light rays (e.g. 131a, 131b, and 131c). The
light-extraction region formed in the same relative position as
light-extraction region 127 of FIG. 14C. In the absence of an
adjacent light-extraction region, light-extraction region 130
illuminates the desired target area with light rays (e.g. 131a,
131b, and 131c) without any blockage as in FIG. 14C.
[0068] Returning to FIG. 14A, the blocked light rays (not shown) by
the adjacent light-extraction region adds to the illuminance on the
respective target area being illuminated by the light-extraction
region blocking the light rays. Some of the light rays (not shown)
from light-extraction region 111a are being blocked by the
light-extraction region 112a and some of the light rays (not shown)
are being blocked by the light-extraction region 111a. This
blockage problem can be solved by dividing the light-extraction
region 111a and 112a in longitudinal segments along the length of
the luminaire in such a manner such that the blockage is reduced
considerably, resulting in increase of the illuminance on the
desired target area.
[0069] FIG. 14E shows a luminaire 110b with light-extraction
regions 111b and 112b. To overcome the above-mentioned blockage
problem, the light-extraction regions are spatially divided into
segments with gaps between the segments along the length of the
luminaire 110b. Light-extraction region 111b is spatially divided
into segments 113 with a gap 113a between adjacent segments.
Similarly, light-extraction region 112b is spatially divided into
segments 114 with a gap 114a between adjacent segments. The
longitudinal dimension of gaps 113a and 114a is at least 20 percent
of the length of the neighboring segments 113 and 114 respectively.
The segments 113 are aligned in such a manner so that each gap 113a
is at least 20 percent of the longitudinal dimension of a segment
114 at the same point along the longitudinal axis of luminaire
110b.
[0070] The longitudinal dimension of gaps 113a and 114a of FIG. 14E
and similar gaps discussed in the following figures are preferably
greater than the radial width of their respective light-extraction
region along the length of the luminaire. More preferably, the
longitudinal dimensions of such gaps are greater than twice the
radial width of their respective light-extraction region along the
length of the luminaire. Further, the target areas illuminated by
the light-extraction regions (e.g., 110a, 110b, FIG. 14E) are
spaced from the luminaire by at least 5 times the longitudinal
dimension of such gaps. This is to assure that the light-extraction
regions appear as continuous from the viewpoint of the target
areas.
[0071] FIG. 14F shows a luminaire 110c with light-extraction
regions 111c and 112c. The light-extraction regions are spatially
divided into segments 115 and 116, respectively. The segments 115
and 116 have respective gaps 115a and 116a between them. The
segments 115 and 116 are arranged in such a manner so that the
longitudinal dimension of the gaps 115a and 116a is equivalent to
the longitudinal dimension of the adjacent segment of the adjacent
light-extraction region.
[0072] FIG. 14G shows a light luminaire 110d with light-extraction
regions 111d and 112d. The light-extraction regions are spatially
divided into segments 117 and 1185 respectively. The segments 117
and 118 have gaps 117a and 118a between them, respectively. The
gaps 117a and 118a are relatively longer than the gaps between the
segments in FIGS. 14E and 14F. This kind of spatial division of the
light-extraction regions greatly reduces the blockage of the light
by the adjacent light-extraction region, which results in an
increase of illuminance on the desired target area.
[0073] The light extractor on a luminaire can be arranged to
preferentially extract light from the luminaire and direct such
light in multiple radial directions along the length of the
side-light emitting portion. This is shown in FIGS. 15A and
15B.
[0074] FIG. 15A is a simplified view of view port 19a and
associated luminaire of the display case 10 of FIG. 1. A desired
target area 135 is illuminated by luminaire 132. The luminaire
receives light from a light source 137, which is extracted by
light-extraction region 133 comprising portions 133a and 133b,
arbitrarily shown cross-hatched. Light-extraction portion 133a of
luminaire 132 illuminates a vertically upper portion 135a of target
area 135 with a peak illuminance 134a. Light-extraction portion
133b illuminates lower portion of target area 135 with a peak
illuminance 134b. Target area 135 is vertically continuous. To the
right of vertically oriented luminaire 132 there are shown a cross
section of the luminaire with light-extraction portion 133a, for
describing the upper half of the luminaire, and a cross section of
the luminaire with light-extraction portion 133b describing the
lower half of the luminaire. These cross sections help to more
clearly show the relative radial positions of light-extraction
portions 133a and 133b on the luminaire. Such radial displacement
of portion 133b relative to portion 133a results in the shift of
peak illuminance 134a to peak illuminance 134b on the target area
135.
[0075] FIG. 15B is a simplified view of view ports 20a and 21a of
the display case 10 of FIG. 1 and an associated but modified
luminaire. A light source 140 provides light to a luminaire 142. In
luminaire 142, a light-extraction region 142a illuminates a target
area 150 at the upper left of the luminaire, having a peak
illuminance 148a. A second light-extraction region 142b illuminates
a separate target area 152 at the lower right of the luminaire,
having a peak illuminance 148b. The single luminaire of FIG. 15B
can illuminate target areas on different lateral sides of the
luminaire. The cross sections of luminaire 142 on either side of
the vertically shown luminaire more clearly show the radial
displacement of light-extraction regions 142a and 142b from each
other.
[0076] A preferred light extractor comprises a layer of paint
exhibiting Lambertian extraction and having a binder with a
refractive index about the same as, or greater than that of, a
core. Suitable light-extraction particles are added to the paint,
such as titanium dioxide or many other materials as will be
apparent to those of ordinary skill in the art. Preferably, the
paint is an organic solvent-based paint.
[0077] Extractors of paint output most of their light in a
preferred radial direction from an elongated luminaire. A textured
type of extractor could alternatively be used, wherein the surface
of the luminaire is textured by molding, laser etching, or chemical
etching. Some textured extractors can extract light with a higher
directionality than paint, but may introduce artifacts into the
light output, which requires a diffuser to mask from view.
[0078] Preferred light-extractors and formulation of gradients of
their efficiency along an elongated luminaire, and along a radial
perimeter of a luminaire are described in the following U.S. patent
applications having some common inventors with the present
application, and assigned to the same joint owners as the present
application: [0079] U.S. patent application Ser. No. 11/366,711
filed 2 Mar. 2006 for Luminaire with Improved Lateral Illuminance
Control by W. Cassarly et al. [0080] U.S. patent application Ser.
No. 11/108,279 filed 18 Apr. 2005 for Efficient Luminaire with
Directional Side-Light Extraction by W. Cassarly et al.
[0081] The present joint owners of the foregoing applications and
of the present application are Fiberstars, Inc. and Optical
Research Associates. The entireties of the disclosures of the
foregoing applications are hereby incorporated by reference.
[0082] FIG. 16 shows a portion of the display case of FIG. 1 with
doors 19 and 20, and illustrates a region of relatively low level
light behind structural member 12b. As shown, luminaires 154a and
154b are mounted on channel 48, which is secured to structural
member 12b. Light rays (e.g. 160a and 160b) originating from a
light-extraction region 156 on luminaire 154b illuminate a desired
target area 166. Target areas 166 and 168 lie in a plane parallel
to the view port of doors 19 and 20, the view ports being shown in
FIG. 1 as 19a and 20a. Light rays (e.g. 162a and 162b) originating
from light-extraction region 158 on luminaire 154a illuminate a
desired target area 168. In the arrangement shown, peak illuminance
on target areas 166 and 168 is at least 50 percent greater than
peak illuminance on non-target area 170 lying between the target
areas in the same plane.
[0083] Various benefits arise because the luminaires in both FIGS.
13 and 16 are blocked from view for a person directly in front of
the luminaire(s). In FIG. 13, a person directly in front of the
display case and luminaire 119 would not see luminaire 119 owing to
the interposition of structural member 12b and channel 48. By
"directly in front" means a person viewing the luminaire along a
plane intersecting the full length of the side-light emitting
portion and being orthogonal to the plane of doors 19 and 20.
Similarly, in FIG. 16, a person directly in front of the display
case and luminaires 154a and 154b would not see the luminaires
owing to the interposition of structural member 12b and channel 48.
By placing the luminaires out of direct view, a person is not
subjected to bright light from the luminaires, providing an
aesthetic advantage.
[0084] Additionally, the fiber optic luminaires more efficiently
direct light onto desired target areas. This is due to their
extraction of light in a highly directional manner. This can be
appreciated from referring to light-extraction regions 120 and 121
(FIG. 13) each of which covers a limited angle around the
circumference of their associated luminaire 119. Either a single
light-extraction region would be used for directing light to a
single target area, or both light-extraction regions would be used
for directing light to two separate target areas as shown in FIG.
13. Compared with a traditional fluorescent lamp, a fiber optic
luminaire of one aspect of the invention will typically provide the
same illuminance on target area(s) with fewer lumens of light.
Thus, referring to FIG. 16, a fiber optic luminaire of one aspect
of the invention will provide relatively less light to non-target
area 170 than will a fluorescent lamp.
[0085] Further, fiber optic luminaires of one aspect of the
invention may deliver light to the target area more efficiently
than fluorescent lamps since they can have smaller cross-sectional
dimension(s) and are thereby less likely to block light which
strikes a reflector. For instance, a fiber optic luminaire
typically would be about 19 mm, or preferably 15 mm, or less in
diameter (for a round luminaire) compared with 25-37 mm diameter
for a typical fluorescent lamp. Because the reflector must often be
placed close to the fluorescent lamp, a substantial amount of light
will restrike the fluorescent lamp after hitting the reflector. The
slimmer luminaire can better accommodate use of reflectors, such as
reflectors 34 and 36.
[0086] FIG. 17 shows a light-delivery system 180 that may replace
the feed-through 76 and associated light-delivery structures shown
in FIG. 1. Light-delivery system 180 comprises an HID lamp 182 with
a collector 184 for collecting light along a main optical axis
coinciding with the main optical axis of a luminaire 186. HID lamp
182 may comprise a metal halide lamp, by way of example. Collector
184 provides light to fiber optic structure 78, which may be
embodied in different forms as described above in connection with
FIG. 9. In the embodiment shown in FIG. 17, fiber optic structure
78 provides light to a separate luminaire 186. Structure 186 is
secured by clamp 38 and the bottom portion of fiber optic structure
78 is secured by clamp 44 and sleeve 46. Feed-through 76 is used in
the same manner as in FIG. 9 above.
[0087] HID lamp 182 and collector 184 are conveniently protected by
a housing 190 mounted atop container 11. The housing may include an
air intake with dust filter (not shown) and a hot air exhaust fan
(not shown). This arrangement does not leave exposed outside the
container any flexible fiber optic cables that could potentially be
damaged if bent or kinked, for instance.
[0088] FIG. 18 shows another light-delivery system 194 that may
replace the feed-throughs 76 and associated light-delivery
structures shown in FIG. 1. Light-delivery system 194 comprises an
HID lamp 182 and collector 184a. However, collector 184a is
configured and positioned to send light directly to a
light-receiving surface 196a of a luminaire 196, via a infra-red
reflecting window 197. Window 197 may be double-paned to further
prevent introduction of heat into the interior of container 11.
Window 197 may be sealed to external wall 58 of the container by
any suitable means, such as adhesive. A similar window 198 may be
sealed to internal wall 56 of the container. If desired, a liner
199 may be inserted between windows 198 and 199 to protect
insulation 62.
[0089] FIG. 19 shows another light-delivery system 200 that may
replace the feed-throughs 76 and associated light-delivery
structures shown in FIG. 1. In system 200, an HID lamp 202 (e.g.,
metal halide) provides light that is collected by non-imaging
collectors 204 and 206. Non-imaging collectors 204 and 206 reduce
the angular distribution of light they collect from HID lamp 202.
Thermal-isolating rods 208 and 210, typically made of glass or
quartz, receive light from collectors 204 and 206, respectively.
Rods 208 and 210 may be curved as shown to reorient light received
by the rods more than 70 degrees, and preferably about 90 degrees
as shown. Rods 208 and 210 may be fed downwardly though the upper
surface of container 11 in the same manner as fiber optic structure
78 of FIG. 9 extends downwardly through container 11. Feed-throughs
212a and 212b may be the same as feed-through 76 of FIG. 9.
Conveniently, rods 208 and 210 can supply light to adjacent
luminaires which respectively direct light to contents of the
container visible through respective view ports (e.g., 19a, 20a,
FIG. 1) in laterally adjacent doors of the container.
[0090] FIG. 20 shows another light-delivery system 214 that may
replace the feed-throughs 76 and associated light-delivery
structures shown in FIG. 1. System 214 includes a halogen lamp 216
and a hollow, dichroic-coated non-imaging collector 218.
Non-imaging collectors do not require imaging, but can include
imaging, as further described in William J. Cassarly, "Non-imaging
Optics: Concentration and Illumination" in the OSA Handbook of
Optics, Volume 3, Chapter 2. Collector 218 couples light onto
optical structure 220. Optical structure 220 may comprise fiber
optic structure 78 of FIG. 9, or window 198 of FIG. 18, by way of
example.
[0091] FIG. 21 shows another light-delivery system 224 that may
replace the feed-throughs 76 and associated light-delivery
structures shown in FIG. 1. System 224 includes one or more
light-emitting diodes (LEDs) 226, whose light is collected by a
non-imaging collector 228, which reduces the angular distribution
of light collected from the one or more LEDs 226. Collector 228
provides light to optical structure 220, as described in connection
with FIG. 20 above.
[0092] FIG. 22 shows another light-delivery system 230 that may
replace the feed-throughs 76 and associated light-delivery
structures shown in FIG. 1. System 230 includes a light source 232,
such as an HID lamp and light collector, a fiber optic optical
splitter 234 for apportioning light into to output arms 234a and
234b from an input arm 234c. Splitter 234 could be formed of glass
or quartz if light source 232 emitted too much heat, or could be
formed of the other materials mentioned above for forming fiber
optic structures such as the luminaires. Optical splitter 234
provides light to luminaires 236a and 236b, which may be located
completely within the container, or may extend upwardly through the
top of the container, as does fiber optic structure 78 of FIG.
9.
[0093] FIG. 23 shows another light-delivery system 238 similar to
that shown in FIG. 22, but showing a variation of system 230 of
that figure. In particular, in system 238, the input arm 240c of
fiber optic optical splitter 240 is oriented more than 70 degrees
(preferably about 90 degrees) from the main optical axis of
luminaires 236a and 236b. This arrangement accommodates a different
orientation of light source 232.
[0094] FIG. 24 shows another light-delivery system 244 that may
replace the feed-throughs 76 and associated light-delivery
structures shown in FIG. 1. System 244 includes a pair of fiber
optic structures 246 and 248 that collectively present their input
faces 246a and 246b to a light source 232. Each of input faces 246a
and 248a preferably have a half-round shape, so as to present a
round shape to light source 232. Each of structures 246 and 248 may
have S-shapes as shown, before being fed through the top of
container 11 with feed-throughs 76 as described above in connection
with FIG. 9. Structures 246 and 248 provide light to luminaires 250
and 252.
[0095] FIG. 25 shows another light-delivery system 254 similar to
that shown in FIG. 24, but showing a variation of system 244 of
that figure. In system 254, light source 232 delivers light along a
main optic axis that is angled more than 70 degrees (preferably
about 90 degrees) from a main optical axis of a luminaire, which
would be vertical for the display case of FIG. 1. A pair of fiber
optic structures 256 and 258 present their input faces 256a and
258a to light source 232. The lower portions of structures 256 and
258 have been omitted, but such lower portions may conform to the
lower portions of structures 246 and 248 of FIG. 24.
[0096] While the invention has been described with respect to
specific embodiments by way of illustration, many modifications and
changes will occur to those skilled in the art. For instance, it
will be routine in the art to incorporate infra-red or ultra-violet
filters in the described fiber optic light-delivery systems where
useful. Additionally, directions used herein, such as "top" or
"downwardly," indicate directions that are exemplary, and are not
to be construed as limiting. It is, therefore, to be understood
that the appended claims are intended to cover all such
modifications and changes as fall within the true scope and spirit
of the invention.
* * * * *