U.S. patent application number 13/906966 was filed with the patent office on 2014-01-16 for scalable led-uv module.
The applicant listed for this patent is Aaron D. Martinez, Stephen J. Metcalf. Invention is credited to Aaron D. Martinez, Stephen J. Metcalf.
Application Number | 20140014857 13/906966 |
Document ID | / |
Family ID | 43623445 |
Filed Date | 2014-01-16 |
United States Patent
Application |
20140014857 |
Kind Code |
A1 |
Martinez; Aaron D. ; et
al. |
January 16, 2014 |
SCALABLE LED-UV MODULE
Abstract
An LED-UV lamp that is easily interchangeable within a UV-curing
process and scalable in length with a fine resolution so that it is
easily customizable to any UV-curing application. The LED-UV lamp
may incorporate multiple rows of LEDs and contain corresponding
optics that effectively deliver radiant power to a substrate at
distances of several inches.
Inventors: |
Martinez; Aaron D.; (Arvada,
CO) ; Metcalf; Stephen J.; (Hudson, WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Martinez; Aaron D.
Metcalf; Stephen J. |
Arvada
Hudson |
CO
WI |
US
US |
|
|
Family ID: |
43623445 |
Appl. No.: |
13/906966 |
Filed: |
May 31, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12868846 |
Aug 26, 2010 |
8558200 |
|
|
13906966 |
|
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Current U.S.
Class: |
250/492.1 ;
250/494.1; 29/592.1 |
Current CPC
Class: |
H01L 33/648 20130101;
B41F 23/0409 20130101; Y10T 29/49002 20150115; B05D 3/067 20130101;
B41F 23/0453 20130101 |
Class at
Publication: |
250/492.1 ;
250/494.1; 29/592.1 |
International
Class: |
B05D 3/06 20060101
B05D003/06 |
Claims
1-20. (canceled)
21. A UV LED lamp, comprising: a connection end cap with electrical
and fluid connections and alignment pins; a cross over end cap; and
a lamp body disposed between said connection end cap and said cross
over end cap and having a first plurality of LEDs emitting UV
radiation, a first reflector positioned to reflect and focus UV
radiation from said first plurality of LEDs onto a substrate, and a
heat sink to absorb heat generated by said LEDs.
22. The UV LED lamp of claim 21, further comprising a second
plurality of LEDs and a second reflector positioned to reflect and
focus UV radiation from said second plurality of LEDs onto said
substrate.
23. A UV LED lamp, comprising: a pair of end caps; a heat sink
mounted between said end caps; a LED segment with a first plurality
of LED subassembly packages, said LED segment having a thermal
interface material, said LED subassembly packages contacting said
thermal interface material; and a first reflector positioned to
reflect and focus radiation from the LED subassembly packages onto
a substrate, wherein said first plurality of LED subassembly
packages is varied in number to accommodate a variable width or
length of said substrate.
24. The UV LED lamp of claim 23, further comprising another LED
segment and a second reflector, said other LED segment with a
second plurality of LED subassembly packages mounted to a second
surface of said heat sink, wherein said second plurality of LED
subassembly packages is varied in number to accommodate said
variable width or length of said substrate, said second reflector
positioned to reflect and focus radiation from the LED subassembly
packages onto said substrate.
25. The UV LED lamp of claim 24, wherein said second plurality of
LED subassembly segments emits a radiation wavelength differing
from a radiation wavelength of said first plurality of LED
subassembly segments.
26. The UV LED lamp of claim 23, further comprising a plurality of
alignment pins extending from one of said end caps.
27. The UV LED lamp of claim 23, further comprising a pair of fluid
valves for admitting coolant to ingress and egress said heat
sink.
28. The UV LED of claim 27, wherein said heat sink defines a pair
of coolant passages, wherein one of said coolant passages admits
coolant ingressing said heat sink and wherein the other of said
coolant passages admits coolant egressing said heat sink.
29. The UV LED of claim 28, wherein each of said coolant passages
is bounded by fin features protruding into said liquid coolant.
30. A method of configuring a UV LED lamp for UV-curing of a
substrate surface, said method comprising: selecting a first
plurality of LED subassembly segments to accommodate a length or a
width of said substrate surface; and placing said plurality of
selected LED subassembly segments within said UV LED lamp.
31. The method of claim 30, further comprising: selecting a second
plurality of LED subassembly segments to accommodate said length or
said width of said substrate surface; and placing said plurality of
selected LED subassembly segments within said UV LED lamp.
32. The method of claim 30, further comprising positioning a
reflector to reflect UV radiation emitted from said LED subassembly
segments to said substrate surface.
33. The method of claim 32, wherein said LED subassembly segments
are attached to a heat sink having a pair of coolant passages.
34. The method of claim 32, further comprising disposing said
reflector and LED subassembly segments between a pair of end
caps.
35. A method of curing materials deposited on a substrate, said
materials having UV photoinitiators, such method comprising
directing UV radiation at said substrate, said UV radiation
originating from the UV LED lamp of claim 21.
36. A method of curing materials deposited on a substrate, said
materials having UV photoinitiators, such method comprising
directing UV radiation at said substrate, said UV radiation
originating from the UV LED lamp of claim 23.
37. A method of curing materials deposited on a substrate, said
materials having UV photoinitiators, such method comprising
directing UV radiation at said substrate, said UV radiation
originating from the UV LED lamp of claim 24.
38. The method of claim 37, wherein a different material is cured
by each of said subassemblies, such subassemblies emitting
differing wavelengths of UV radiation.
39. The method of claim 37, further comprising cooling said UV
subassembly segments.
40. The method of claim 39, wherein said UV subassembly segments
are cooled by circulating coolant through a pair of coolant
passages located in said heat sink.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn.119
(e) to, and hereby incorporates by reference, U.S. Provisional
Application No. 61/237,455, filed 27 Aug. 2009, U.S. Provisional
Application No. 61/267,021, filed 5 Dec. 2009, and U.S. Provisional
Application No. 61,237,436, filed 27 Aug. 2009 and is a
continuation of, and hereby incorporates by reference, U.S. patent
application Ser. No. 12/868,846, filed 26 Aug. 2010.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to LED-UV lamps. More
particularly, the invention is suitably used in the application of
UV-curing of inks, coatings, and adhesives having UV photo
initiators therein.
[0004] 2. Background
[0005] UV LED lamps are permanently mounted within the UV-curing
process.
[0006] Depending upon the optics used, the UV LED lamps can be
required to be located at a specific distance from the substrate so
that uniformity and intensity are optimized. Some UV LED lamps are
scalable in length with coarse resolution.
[0007] UV LED lamps are mounted into a UV-curing process in a
manner that makes them difficult and time consuming to remove for
cleaning, maintenance, or the like. UV LED lamps are mounted in
fixed positions within the UV-curing process where the location
within the position is often determined by the process machinery
into which the UV curing LED lamps are being integrated.
[0008] Different positions within the UV-curing process could
require the UV LED lamps to be at different locations with respect
to the substrate. A conflict could arise between the location
required by the optics of the lamp and the location determined by
the machinery of a UV-curing process which scenario could render
the UV LED lamp unsuitable for placement in particular positions
within a UV-curing process.
[0009] If a lamp is required at an alternate location, either an
existing lamp must be uninstalled from an existing location and
reinstalled at the desired location which option would only be
suitable if the location required by the optics of the UV LED lamp
is compatible with the location available in the desired position,
or a new lamp must be purchased possibly with redesigned optics. UV
LED lamps of different wavelength would also not be easily
interchangeable.
[0010] The coarse resolution in length scalability could result in
the scenario where the lamp length options that are available are
either too short or too long for a particular application which may
make the UV LED lamps difficult or impossible to install into some
UV-curing applications. For example, if the length of a UV LED lamp
was scalable in 3 inch increments, and a 40 inch lamp was required,
the options would either be 39 inches (13.times.3 inches), or 42
inches (14.times.3 inches). The 39 inch lamp would be too short and
could result in uncured product at the ends of the lamp. The 42
inch lamp could be too long to fit into the envelope that is
available within the UV-curing process.
SUMMARY OF THE INVENTION
[0011] LEDs are mounted onto short subassembly segments that may be
produced in assorted lengths which segments are then easily mounted
into the LED-UV module in a row running along the length of the
module.
[0012] Assembling the LEDs in segments that are easily mounted into
the LED-UV module would simplify the process of LED replacement and
possibly make the process less expensive. If an LED fails, the
segment whereon the failed LED had been assembled can be
disconnected, removed, and then a new segment can be installed in
its place.
[0013] The LEDs may degrade as they get older and their output
power may decrease below an acceptable level for their application.
In this case the owner of the LED-UV lamp would have the option of
replacing the segments with new ones as opposed to replacing the
whole module.
[0014] LEDs are solid state semiconductor devices. The efficiency
and power output of LEDs can increase from one generation to the
next as scientific breakthroughs are made and manufacturing
processes improve. The owner of the LED-UV module would have the
option to easily upgrade the module by swapping out old segments
for new ones with improved operating characteristics.
[0015] Providing the segments in an assortment of lengths could
enable the length of the row of segments to be scalable with a
finer resolution than what may be possible if all of the segments
where the same length, while at the same time the total number of
parts required to assemble the row of LEDs could be reduced. For
example, the segments could be configured in a 3 inch version, a 4
inch version, and a 6 inch version. A 12 inch row of segments could
then be assembled by connecting 2 of the 6 inch segments. A 13 inch
row of segments could be assembled by connecting a 6 inch segment,
a 4 inch segment, and a 3 inch segment. A 14 inch row of segments
could be assembled by connecting a 6 inch segment and two 4 inch
segments. The row of LEDs could be assembled in a variety of
lengths with a 1 inch resolution. On the other hand, if only one
segment was made, in a 3 inch version for example, the resolution
of the possible LED row lengths would be 3 inches, resulting in
fewer length options available for customizability. The segment
could be made in a 1 inch version to achieve a 1 inch resolution,
but doing so could increase the complexity of the assembly by
increasing the number of parts required to construct a row.
[0016] The main module body contains a surface extending the length
of the module, whereon the LED segments can be mounted.
[0017] This surface provides correct positioning and easy mounting
of the LED segments.
[0018] The main module body contains an integral heat sink feature
with coolant passages that run the length of the module and are
positioned such that they pass near the surface whereon the LED
segments mount.
[0019] The heat sink feature provides a simple means of effectively
extracting heat from the LEDs. This maintains the LED junction
temperature at an acceptably low level thus maximizing the life of
the LEDs.
[0020] The module is designed so that it is interchangeable and can
therefore be quickly and easily installed into or removed from
docking ports that are rigidly mounted into a UV-curing process
without the use of tools.
[0021] Interchangeability allows the modules to be easily removed
from the UV-curing process for cleaning, repair, maintenance, or
the like. LED-UV modules of different wavelengths can be installed
into the UV-curing process and the modules can be moved between
different locations within the UV-curing process as long as there
is a docking port available. Removal and installation of the LED-UV
modules from the associated docking ports within a UV-curing
process is a tool-less procedure and can be done by a person of no
extraordinary skill.
[0022] All necessary connections (e.g. power, communication, liquid
cooling) are made automatically upon installation of the LED-UV
module into a docking port, and then disconnected automatically
during the removal of the LED-UV module from a docking port.
[0023] Automatic engaging and disengaging of the connections
between the LED-UV module and the docking port upon insertion and
removal of the LED-UV module ensure that the connections are made
properly, save time, and make the overall operation of the
UV-curing process more convenient for the user.
[0024] All connection devices (e.g. electrical pins, coolant
valves) are positioned such that they do not protrude beyond the
outer surfaces of the LED-UV module.
[0025] Designing the connections such that they do not protrude
beyond the outer surfaces of the module protects them from damage.
With the LED-UV module being designed in a manner that the module
is easily removable from the UV-curing process, the possibility of
damage to the connections that could result from handling the
module will be significantly reduced.
[0026] The LED-UV module can incorporate a common optical design
using a parabolic or elliptical trough reflector that allows for
varying distances and mounting locations with respect to the
substrate being cured without a significant loss of uniformity or
optical (irradiant) intensity.
[0027] LEDs, by themselves, typically exhibit a Lambertian
radiation pattern in which the intensity of the light output by the
LED chip is directly proportional to the cosine of the angle
between the point of observation and the surface normal of the LED
chip. An elliptical or parabolic trough reflector can effectively
gather the light and project it onto a substrate that is positioned
at varying distances (i.e. from fractions of an inch to several
inches) from the base of the LED-UV module with a minimal loss in
intensity and in a very uniform manner.
[0028] Without the use of a reflector, the LED-UV module may need
to be placed at either a fixed optics-dependent distance from the
substrate or much closer to the substrate than would be allowable
by some UV-curing processes or some positions within a UV-curing
process. One example could be in a sheet-fed printing press. In
sheet-fed printing, it is typically desirable to locate one or more
LED-UV modules immediately following the application of one or more
UV-curable inks following the inking units of the printing machine
in order to "pin" or "dry" the UV-curable inks or spot varnishes
prior to the application of a UV-curable coating at the end of the
press prior to the delivery of sheets onto a pile. For inking unit
curing locations (immediately following the inking units), it would
be desirable to locate the LED-UV modules closer (typically 1 to 3
inches) to the substrate for the benefit of easier mechanical
mounting in order to fit within the space constraints provided by
various makes and models of printing machines. However, at
end-of-press curing locations, the method of sheet transfer
provided by most printing machines prohibits closer mechanical
location through the end-of-press sheet delivery area and would
require the LED-UV module to be mounted as far as 3 to 5 inches
away from the substrate. If the LED-UV module where placed too
close to the substrate it would collide with the moving machinery
of the printing press. The use of reflector style optics enables a
single, interchangeable design of the LED-UV module of the
invention to be placed in multiple docking or mounting positions at
differing distances to the substrate without significant loss of
optical uniformity or radiant intensity within a UV-curing process
that would otherwise have inaccessible or impractical mounting
locations and/or require multiple, non-interchangeable optical
designs of the LED-UV modules between the various positions of the
process.
[0029] The LED-UV modules would be available in a variety of UV
wavelengths and each wavelength module would be interchangeable
with the others and could therefore be applied to any docking port
within the UV-curing process.
[0030] Different types of UV curable products can cure most
effectively when irradiated by different wavelengths of UV light.
For example, clear products may cure most effectively with longer
wavelength UV light, while darker, more heavily pigmented products
may cure more effectively with shorter wavelength UV light. Overall
system performance may be maximized by the ability to interchange
LED-UV modules of different wavelength within the UV-curing process
depending upon the preferences of the UV-curable product that is
being cured.
[0031] The LED-UV module could incorporate multiple, adjacent,
parallel rows of LEDs where each row shines into a corresponding
trough reflector.
[0032] Incorporating multiple, adjacent, parallel rows of LEDs
where each row shines into a corresponding trough reflector would
increase the radiant power output by the LED-UV module by a factor
equal to the number of rows of LEDs. A single lamp of this
embodiment could have the same radiant power output as multiple
lamps of the single row embodiment with the added advantages of
lower cost and smaller form factor compared to multiple lamps of
the single row embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is an isometric view of one embodiment of the LED-UV
module of the invention.
[0034] FIG. 2a is a top view of the embodiment of FIG. 1.
[0035] FIG. 2b is a side view of the embodiment of FIG. 1.
[0036] FIG. 2c is an end view of the embodiment of FIG. 1.
[0037] FIG. 3 is a cross section view of the embodiment of the
LED-UV module shown in FIGS. 1 and 2 along line A-A of FIG. 2b.
[0038] FIG. 4 is a perspective view of one embodiment of an LED
segment assembly of the invention.
[0039] FIG. 5 is a cross sectional view of one embodiment of the
application of a trough reflector to aid in the transference of UV
light from the LEDs onto the substrate.
[0040] FIG. 6 is an isometric view of another embodiment of the
LED-UV module of the invention incorporating a plurality of
adjacent, parallel rows of LEDs and multiple trough reflectors.
[0041] FIG. 7a is a top view of the LED-UV module shown in FIG.
6.
[0042] FIG. 7b is a side view of the LED-UV of FIG. 6.
[0043] FIG. 7c is an end view of the LED-UV module shown in FIG.
6.
[0044] FIG. 8 is a cross section view of the embodiment of the
LED-UV module shown in FIGS. 6 and 7a-c along line A-A of FIG.
7b.
[0045] FIG. 9 is an illustration of one embodiment of the
application of a plurality of trough reflectors to aid in the
transference of UV light from the LEDs onto the substrate and to
multiply the available radiant power.
[0046] It is understood that the above-described figures are only
illustrative of the present invention and are not contemplated to
limit the scope thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0047] The following is a description of possible embodiments of
the LED-UV module of the invention. The examples and figures that
follow are intended to teach a person skilled in the art how to
effectively design and implement the present invention, but are not
intended to limit the scope of the invention. The features and
methods disclosed in the detailed description may be used
separately or in conjunction with other features and methods to
provide improved devices of the invention and methods for making
the same. The features and methods disclosed in this detailed
description may not be necessary to practice the invention in the
broadest sense, but are provided so that a person of skill in the
art may further understand the details of the invention.
[0048] Another description of the LED-UV lamp of this invention, as
well as a docking system accommodating such lamp, is present in
U.S. patent application Ser. No. 12,868,827, entitled
Interchangeable UV LED Curing System, and filed concurrently with
this application, the entire disclosure of such application hereby
incorporated by reference.
[0049] Referring to FIGS. 1, 2a-c, and 3, an LED-UV module 100 is
shown having electrical connections 102, coolant valves 104, a
module body 106, a module cover 108, a connection end cap 110, a
cross-over end cap 112, alignment pins 114, a transparent cover
116, a trough reflector 118, coolant passages 120, LED segments
122, and a surface 124 on the module body 106 to mount the LED
segments 122.
[0050] The electrical connections 102 would be located on the
connection end 126 of the LED-UV module 100 and may be mounted onto
the connection end cap 110. To protect the electrical pins 102 from
damage during handling of the LED-UV module 100, the electrical
connections 102 could be mounted to the connection end cap 110 in a
recessed fashion so that they do not protrude beyond the outer
surfaces of the connection end cap 110. The electrical connections
102 would be used to transfer power and possibly communications
from the LED-UV module 100 to mating electrical connections that
would be present in the docking ports within the UV-curing process.
The electrical connections could be pin and socket type
connections.
[0051] The coolant valves 104 would be located on the connection
end 126 of the LED-UV module 100 and may be mounted onto the
connection end cap 110. To protect the coolant valves 104 from
damage during handling of the LED-UV module 100, the coolant valves
104 could be located on the connection end cap 110 such that they
do not protrude beyond the outer surfaces of the connection end cap
110. The coolant valves 104 would connect to mating coolant valves
that would be present in the docking port and would provide a
supply and return for cooling fluid to flow through the LED-UV
module 100. The coolant valves 104 and the mating coolant valves in
the docking port could be spring actuated poppet style valves that
would automatically be pushed open when they are engaged, and
automatically spring closed when they are disengaged.
[0052] The module body 106 would be the main supporting component
of the LED-UV module 100. Two significant features on the module
body 106 could be the surface 124 that locates the LED segments
122, and the coolant passages 120. The module body 106 could
support one edge of the transparent cover 116. The module body 106
could be made of an extrusion out of a material that is a good heat
conductor such as aluminum.
[0053] The module cover 108 would serve as the final component of
the LED-UV module 100 assembly and cover all of the internal
components. The module cover 108 could contain a feature that would
hold the trough reflector 118 in the correct position and shape.
The module cover 108 could support one edge of the transparent
cover 116. The module cover 108 could be made of an extrusion and
the material could suitably be the same as the material of the
module body 106.
[0054] The connection end cap 110 would serve as the mounting
structure for the electrical connections 102, coolant water valves
104, and the alignment pins 114. The connection end cap 110 would
mount to the appropriate end of the module body 106 forming the
connection end 126 of the LED-UV module 100. Power and
communications would pass through the connection block 110 into the
inside of the LED-UV module 100 through the electrical connections
102. Liquid coolant would flow between the coolant valves 104 and
the coolant passages 120 at the interface 128 where the connection
block 110 mounts to the module body 106. This interface may be
sealed by a gasket such as an o-ring to prevent liquid coolant from
leaking at the interface 128.
[0055] The cross-over end cap 112 would mount to the end of the
module body 106 that is opposite the connection block 110 forming
the cross-over end 130 of the LED-UV module 100. The cross-over end
cap would contain a passage that would connect one of the coolant
passages 120 to the other thus forming a circuit for liquid coolant
to flow into the LED-UV module 100 through one of the coolant
valves 104, through one of the water passages 120, through the
passage in the cross-over end cap 112 through the other of the
water passages 120, and then out of the LED-UV module 100 through
the other of the coolant valves 104. The interface 132 between the
cross-over end cap 112 and the module body 106 could be sealed with
a gasket such as an o-ring to prevent liquid coolant from leaking
at the interface 132.
[0056] The alignment pins 114 would be located on the connection
end of the LED-UV module and may be mounted to the connection block
110. The alignment pins 114 could serve to align the connections
102, 104 prior to their engagement with the mating connections
present in the docking port.
[0057] The transparent cover 116 would most suitably be made of a
durable material that would be highly UV transparent such as
quartz, glass, acrylic, or the like. The transparent cover 116
would serve as a protective window that would protect the internal
components of the LED-UV module while allowing the light generated
by the LEDs to pass through the transparent cover. The transparent
cover could be supported on one edge by the module body 106 and
supported on the opposite edge by the module cover 108. The ends
134 of the transparent cover 116 could be trapped by the connection
end cap 110 on one end and the cross-over end cap 112 on the
other.
[0058] The reflector 118 would be made of a highly UV reflective
material such as acrylic mirror, polished metal, or the like, and
could be formed into shape prior to installation into the LED-UV
module 100. The reflector 118 could be held in position and shape
by a mating feature in the module cover 108. The reflector could be
trough shaped and may incorporate a parabolic or elliptical
geometry that would transfer the UV light emitted by the LEDs onto
the substrate.
[0059] The coolant passages 120 would run the length of the module
body 106 and be positioned so that they pass near the surface 124
whereon the LED segments 122 mount. The coolant passages 120
facilitate the removal of heat generated by the LEDs and may be
dimensioned and located such that the temperature of the module
body 106 is essentially uniform over a length of such module. Heat
generated at the P/N junctions of the LEDs is conducted from the
LED segments 122, into the module body 106 where it is transferred
to the liquid coolant by means of convection at the surfaces of the
coolant passages 120. The coolant passages could contain fin
features 136 that protrude into the liquid coolant. The fin
features 136 would serve to increase the convective surface area of
the coolant passages 120 as well as generate turbulence in the
liquid coolant that would increase the associated convection
coefficient. The fin features could also increase the rate of heat
conduction through the module body. The presence of fin features
136 in the coolant passages 120 would serve to increase the rate of
heat convection from the module body 106 to the liquid coolant,
ultimately resulting in lower LED junction temperatures. Lower LED
junction temperatures could enable longer LED lifetimes.
[0060] One embodiment of an LED segment 122 is shown in FIG. 4. The
LED segment 122 could consist of a heat transfer plate 138, a
plurality of LED packages or segments 140, thermal interface
material 142, and fasteners 144 to attach the LED packages 140 to
the heat transfer plate 138. The LED packages 140 could be
off-the-shelf packages such as Luminus PhlatLights.RTM., or they
could be custom designed. The LED package 140 specifications could
suitably be low thermal resistance, high powered UV output, and
quick disconnect power terminals 146. The LED segment 122 could
contain mounting features such as bolt holes 148 to enable
fastening to the module body 106 in a manner that maximizes heat
transfer from the LED segment 122 to the module body 106. Multiple
LED segments 122 could suitably be mounted to the module body in a
lengthwise, end-to-end configuration to form a long row of LEDs.
The LED segments 140 would be designed in a manner that maximizes
the LED line density (i.e. number of LEDs per inch) and the LED
segments 140 could be designed in an assortment of lengths which
would enable finer length resolution when assembling the LED
segments 140 in a lengthwise, end-to-end configuration to form a
long row of LEDs. The finer length resolution would facilitate
customizability for a variety of different length UV-curing
applications. Providing the segments 140 in an assortment of
lengths could enable the length of the row of segments 140 to be
scalable with a finer resolution than what may be possible if all
of the segments 140 were the same length, while at the same time
the total number of parts required to assemble the row of LEDs
could be reduced. For example, the segments 140 could be configured
in a 3 inch version, a 4 inch version, and a 6 inch version. A 12
inch row of segments 140 could then be assembled by connecting 2 of
the 6 inch segments. A 13 inch row of segments 140 could be
assembled by connecting a 6 inch segment, a 4 inch segment, and a 3
inch segment. A 14 inch row of segments 140 could be assembled by
connecting a 6 inch segment and two 4 inch segments. The row of LED
segments 140 could be assembled in a variety of lengths with a 1
inch resolution. On the other hand, if only one segment 140 was
made, in a 3 inch version for example, the resolution of the
possible LED row lengths would be 3 inches, resulting in fewer
length options available for customizability. The segment 140 could
be made in a 1 inch version to achieve a 1 inch resolution, but
doing so could increase the complexity of the assembly by
increasing the number of parts required to construct a row.
[0061] FIG. 5 illustrates how the implementation of a trough
reflector 118 could effectively transfer light 150 from the LEDs
onto a substrate 152 at a distance 154 of several inches. This type
of optical configuration would be very suitable for UV-curing
applications wherein it is not possible to place the LED-UV module
in close proximity to the substrate.
[0062] Some UV-curing applications may require more UV power than
an LED-UV module 100 having a single row of LED segments 122 can
provide. An alternative embodiment of the LED-UV module 100 of the
invention could consist of two or more adjacent, parallel rows of
LED segments 122 shining into separate trough reflectors 118.
[0063] Referring to FIGS. 6, 7a-c, and 8, an LED-UV module 200 is
shown having electrical connections 202, coolant valves 204, a
first module cover 206, a second module cover 208, a connection end
cap 210, a cross-over end cap 212, alignment pins 214, a
transparent cover 216, a plurality of trough reflectors 218,
coolant passages 220, LED segments 122, a heat sink 224, and
surfaces 226 on the heat sink 224 to mount the LED segments
122.
[0064] The electrical connections 202 would be located on the
connection end 228 of the LED-UV module 200 and may be mounted onto
the connection end cap 210. The electrical connections 202 would be
used to transfer power and possibly communications from the LED-UV
module 200 to mating electrical connections that would be present
in the docking ports within the UV-curing process. The electrical
connections could be pin and socket type connections.
[0065] The coolant valves 204 would be located on the connection
end 228 of the LED-UV module 200 and may be mounted onto the
connection end cap 210. To protect the coolant valves 204 from
damage during handling of the LED-UV module 200, the coolant valves
204 could be located on the connection end cap 210 such that they
do not protrude beyond the outer surfaces of the connection end cap
210. The coolant valves 204 would connect to mating coolant valves
that would be present in the docking port and would provide a
supply and return for cooling fluid to flow through the LED-UV
module 200. The coolant valves 204 and the mating coolant valves in
the docking port could be spring actuated poppet style valves that
would automatically be pushed open when they are engaged, and
automatically spring closed when they are disengaged.
[0066] The first module cover 206 would cover one side of the
LED-UV module 200. The first module cover 206 could contain a
feature that would hold one of the trough reflectors 218 in the
correct position and shape and the first module cover 206 could
support one edge of the transparent cover 216. The first module
cover 206 could be made of an extrusion out of a material such as
aluminum or plastic.
[0067] The second module cover 208 would cover the other side of
the LED-UV module 200. The second module cover 208 could contain a
feature that would hold another of the trough reflectors 218 in the
correct position and shape and the second module cover 208 could
support the other edge of the transparent cover 216. The second
module cover 208 could be made of an extrusion out of a material
such as aluminum or plastic.
[0068] The connection end cap 210 would serve as the mounting
structure for the electrical connections 202, coolant water valves
204, and the alignment pins 214. The connection end cap 210 would
mount to the appropriate end of the LED-UV module 200 forming the
connection end 228 of the LED-UV module 200. Power and
communications would pass through the connection block 210 into the
inside of the LED-UV module 200 through the electrical connections
202. Liquid coolant would flow between the coolant valves 204 and
the coolant passages 220 at the interface 230 where the connection
block 210 mounts to the heat sink 224. This interface may be sealed
by a gasket such as an o-ring to prevent liquid coolant from
leaking at the interface 230.
[0069] The cross-over end cap 212 would mount to the end of the
LED-UV module 200 that is opposite the connection block 210 forming
the cross-over end 232 of the LED-UV module 200. The cross-over end
cap 212 would contain a passage that would connect one of the
coolant passages 220 to the other thus forming a circuit for liquid
coolant to flow into the LED-UV module 200 through one of the
coolant valves 204, through one of the water passages 220, through
the passage in the cross-over end cap 212 through the other of the
water passages 220, and then out of the LED-UV module 200 through
the other of the coolant valves 204. The interface 234 between the
cross-over end cap 212 and the module body 206 could be sealed with
a gasket such as an o-ring to prevent liquid coolant from leaking
at the interface 234.
[0070] The alignment pins 214 would be located on the connection
end of the LED-UV module and may be mounted to the connection block
210. The alignment pins 214 could serve to align the connections
202, 204 prior to their engagement with the mating connections
present in the docking port.
[0071] The transparent cover 216 would most suitably be made of a
durable material that would be highly UV transparent. The
transparent cover 216 would serve as a protective window that would
protect the internal components of the LED-UV module while allowing
the light generated by the LEDs to pass through the transparent
cover 216. The transparent cover 216 could be supported on one edge
by the first module cover 206 and supported on the opposite edge by
the second module cover 208. The ends 234 of the transparent cover
216 could be trapped by the connection end cap 210 on one end and
the cross-over end cap 212 on the other.
[0072] The reflectors 218 would be made of a highly UV reflective
material and could be formed into shape prior to installation into
the LED-UV module 200. The reflectors 218 could be held in position
and shape by mating features in the first and second module covers
206 and 208. The reflectors 218 could be trough shaped and may
incorporate a parabolic or elliptical geometry that would transfer
the UV light emitted by the LEDs onto the substrate.
[0073] The coolant passages 220 would run the length of the heat
sink 224 and be positioned so that they pass near the surface 226
whereon the LED segments 122 mount. The coolant passages 220
facilitate the removal of heat generated by the LEDs. Heat
generated at the P/N junctions of the LEDs is conducted from the
LED segments 122, into the heat sink 224 where it is transferred to
the liquid coolant by means of convection at the surfaces of the
coolant passages 220. The coolant passages could contain fin
features 238 that protrude into the liquid coolant. The fin
features 238 would serve to increase the convective surface area of
the coolant passages 220 as well as generate turbulence in the
liquid coolant that would increase the associated convection
coefficient. The fin features 238 could also increase the rate of
heat conduction through the module body. The presence of fin
features 238 in the coolant passages 220 would serve to increase
the rate of heat convection from the heat sink 224 to the liquid
coolant, ultimately resulting in lower LED junction temperatures.
Lower LED junction temperatures could enable longer LED
lifetimes.
[0074] FIG. 9 illustrates how the implementation of a plurality of
trough reflectors 218 could effectively transfer light 240 from the
multiple, adjacent, parallel rows of LEDs onto a substrate 242 at a
distance 244 of several inches. This type of optical configuration
would be very suitable for UV-curing applications wherein it is not
possible to place the LED-UV module in close proximity to the
substrate and where the power of multiple LED-UV lamps 100 is
required in a single location.
[0075] The LED-UV modules 100, 200 of the invention could be
produced in an assortment of models where each model would have a
different peak wavelength, or could have a plurality of peak
wavelengths, in its spectral output depending on the LEDs used in
the LED segments 122. To achieve a plurality of peaks in the
spectral output of the LED-UV modules 100,200, a mixture of LEDs of
different UV wavelength could be used, in an alternating pattern,
within each LED segment 122. A single LED-UV module 100,200 with a
single peak wavelength in its spectral output is contemplated to be
within the spirit and scope of this invention. Additionally, a
single LED-UV module 100,200 with a plurality of peak wavelengths
in its spectral output is contemplated to be within the spirit and
scope of this invention.
[0076] Having different models of LED-UV modules 100,200 available,
each with a different peak wavelength output, or emitting a
plurality of peak wavelengths, and where the LED-UV modules 100,200
are interchangeable within a UV-curing process would increase the
flexibility of the UV-curing system. Many LED-UV lamps are
available in an assortment of UV wavelengths and some with the
option of multiple peaks in their spectral output. The LED-UV
modules 100,200 of this invention would be designed such that they
can be quickly inserted into and removed from a UV-curing process
without the use of tools provided that the associated docking ports
are mounted into the UV-curing process. A model of an LED-UV module
100,200 of one UV spectral output can be removed and a model of a
different UV spectral output can be inserted in a matter of minutes
by a person of no extraordinary skill.
[0077] A person of ordinary skill in the art will readily
appreciate that individual components shown on various embodiments
of the present invention are interchangeable to some extent and may
be added or interchanged on other embodiments without departing
from the spirit and scope of this invention.
[0078] Because numerous modifications of this invention may be made
without departing from the spirit thereof, the scope of the
invention is not to be limited to the embodiments illustrated and
described. Rather, the scope of the invention is to be determined
by the appended claims and their equivalents.
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