U.S. patent application number 12/057034 was filed with the patent office on 2009-01-15 for rf shielding for aircraft windows.
This patent application is currently assigned to ROW 44, LLC. Invention is credited to Gregg Fialcowitz, John Guidon.
Application Number | 20090014589 12/057034 |
Document ID | / |
Family ID | 37802708 |
Filed Date | 2009-01-15 |
United States Patent
Application |
20090014589 |
Kind Code |
A1 |
Guidon; John ; et
al. |
January 15, 2009 |
RF Shielding for Aircraft Windows
Abstract
A window includes a pane and a geometrically patterned grid. The
grid is embedded in the pane and the grid comprises an electrically
conductive material and is operable to attenuate radio frequency
(RF) energy.
Inventors: |
Guidon; John; (Thousand
Oaks, CA) ; Fialcowitz; Gregg; (Northridge,
CA) |
Correspondence
Address: |
SINSHEIMER JUHNKE LEBENS & MCIVOR, LLP
1010 PEACH STREET, P.O. BOX 31
SAN LUIS OBISPO
CA
93406
US
|
Assignee: |
ROW 44, LLC
Porter Ranch
CA
|
Family ID: |
37802708 |
Appl. No.: |
12/057034 |
Filed: |
March 27, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11187062 |
Jul 21, 2005 |
7350753 |
|
|
12057034 |
|
|
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|
Current U.S.
Class: |
244/129.3 |
Current CPC
Class: |
B64D 45/0063 20190801;
H05K 9/0005 20130101; B64C 1/1484 20130101 |
Class at
Publication: |
244/129.3 |
International
Class: |
B64C 1/14 20060101
B64C001/14 |
Claims
1. A window comprising; a pane; and a geometrically patterned grid
embedded in the pane, the grid comprising an electrically
conductive material and operable to attenuate radio frequency (RF)
energy.
2. The window of claim 1 wherein the grid is electrically connected
to ground.
3. The window of claim 1 wherein the grid is comprised of generally
square openings.
4. The window of claim 1 wherein the grid is comprised of generally
triangular openings.
5. The window of claim 1 wherein the grid is comprised of at least
one fractal-derived shape.
6. A method of attenuating radio frequency (RF) energy in a window
comprising: providing a pane; forming a geometrically patterned
grid of electrically conductive material; embedding a geometrically
patterned grid in the pane; receiving RF energy at the pane; and
attenuating the received RF energy utilizing the grid.
7. The method of claim 6 further comprising electrically connecting
the grid to ground.
8. The method of claim 6 wherein forming a geometrically patterned
grid comprises forming the grid of generally square openings.
9. The method of claim 6 wherein forming a geometrically patterned
grid comprises forming the grid of generally triangular
openings.
10. The method of claim 6 wherein forming a geometrically patterned
grid comprises forming of at least one fractal-derived shape.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. application Ser. No.
11/187,062, now U.S. Pat. No. 7,350,753, filed on Jul. 21, 2005,
which is hereby incorporated herein by reference in its
entirety.
FIELD OF INVENTION
[0002] This relates to improvements in window units installed in
aircraft of all types. Specifically, this relates to aircraft
windows capable of shielding against the transmission of radio
frequency (RF) energy.
BACKGROUND
[0003] The increasing usage of cellular telephones and other
wireless electronic devices generally has given rise to a demand
for the use such devices by passengers while traveling in aircraft.
In most commercial aircraft, however, the passengers are prohibited
from using these wireless devices, since their use interferes with
services outside the aircraft. When activated on board aircraft,
cellular telephones will actively try, and sometimes succeed, in
communicating via ground based cellular infrastructure. This is
undesirable, and not allowed by government regulations.
[0004] As shown in FIG. 1, an aircraft 10 has an aluminum exterior
12, a passenger compartment 14 and a plurality of windows 16. It is
believed, that the primary means of transmission of RF energy
between the passenger compartment 14 and the exterior of the
aircraft 10 is via the windows 16. This includes the transmission
of electromagnetic transmission frequencies currently in use for
cellular phones which commonly operate in the 800 Mhz to 5 Ghz
frequency range.
[0005] There is a need, therefore, for improved aircraft windows
that are transparent to electromagnetic energy in the visible
spectrum, yet opaque to RF energy.
SUMMARY OF THE ILLUSTRATED EMBODIMENTS
[0006] Disclosed is an improved aircraft window, where RF shielding
is desirable. In one embodiment, a window shield comprises an
electrically conductive, transparent flexible film, which is
applied by known processes to a window pane. This shield is
grounded to the aircraft frame or exterior by a "tail" of
conductive material, which is secured to a ground point in the
vicinity of the window pane.
[0007] In an alternative embodiment, a window pane may support
elements of conductive material embedded in the pane which are
formed into patterns such as grids, that are adapted to absorb
energy at the wavelengths emitted by cell phones, or to absorb
other radiation.
[0008] Embodiments of the present invention therefore allow visible
light to pass through an aircraft window while shielding certain
other electromagnetic energy. The improved window will facilitate
use of certain electronic devices within the aircraft, without
interference being caused by or to other signals, outside the
plane.
[0009] There are additional aspects to the present invention. It
should therefore be understood that the preceding is merely a brief
summary of some, embodiments and aspects of the present inventions.
Additional embodiments and aspects of the present inventions are
referenced below. It should further be understood that numerous
changes to the disclosed embodiments can be made without departing
from the spirit or scope of the inventions. The preceding summary
therefore is not meant to limit the scope of the inventions.
Rather, the scope of the inventions is to be determined by appended
claims and their equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These and/or other aspects and advantages of the present
invention will become apparent and more readily appreciated from
the following description of the preferred embodiments, taken in
conjunction with the accompanying drawings of which:
[0011] FIG. 1 is an exterior view of a portion of an aircraft
having a plurality of windows;
[0012] FIG. 2 is an interior view of a portion of an aircraft with
two window assemblies in accordance with an embodiment of the
invention;
[0013] FIG. 3 is an aircraft window pane of one of the window
assemblies of FIG. 2;
[0014] FIG. 4 is an aircraft window pane in accordance with another
embodiment of the invention;
[0015] FIG. 5 is an aircraft window pane in accordance with yet
another embodiment of the invention;
[0016] FIG. 6 is an enlarged sectional view of the window pane of
FIG. 5 taken along the line 6-6 of FIG. 5;
[0017] FIG. 7 is an aircraft window assembly in accordance with
another embodiment of the invention; and
[0018] FIG. 8 is the window shade of FIG. 7.
DETAILED DESCRIPTION
[0019] Reference will now be made in detail to embodiments of the
present invention, examples of which are illustrated in the
accompanying drawings, wherein like reference numerals refer to
like elements throughout. It is understood that other embodiments
may be utilized and structural and operational changes maybe made
without departing from the scope of the present invention.
[0020] FIG. 2 is a simplified diagram of a portion of the interior
of an aircraft that includes windows in accordance with an
embodiment of the invention. Referring to FIGS. 2 and 3, the
aircraft interior includes an interior bulkhead 20, a window frame
22, and a window 24. The window 24 has a transparent pane 26 having
an inner surface 28 and an outer surface 30. A transparent
conductive film 32 overlays the inner surface 28 of the pane 26.
The film 32 is constructed of a material that is transparent to
visible light but adapted to attenuate RF energy. An exemplary
material that would satisfy this purpose is Scotchtint.TM. which
can be obtained from 3M Company located in St. Paul, Minn.
[0021] In order to better attenuate the RF energy, the film 32 is
electrically grounded. This electrical grounding is accomplished by
a pigtail of the same material (not shown), extending outwardly
from a point on the perimeter of the film 32, and attached by
conductive adhesive to any convenient nearby point that is
electrically connected to the skin of the aircraft, but usually the
inside of the skin of the aircraft itself. In alternative
embodiments, however, electrical grounding can be accomplished by
other means known in the art. For purposes of this application, and
in view of the use of embodiments of the invention in the context
of an aircraft that is airborne, reference herein to ground and to
electrical grounding includes making an electrical connection to
the conductive skin of an aircraft while it is airborne.
[0022] The film 32 can be applied to the inner surface 28 by any of
at least two methods. One involves moistening the film on the side
to be applied to the window, then positioning the film and applying
pressure with a roller to ensure close contact between the film and
the glass. Another method is to use a film that is already coated
on one side with a layer of clear adhesive and press that side
against the window.
[0023] Because the film 32 is applied to the inner surface 28 of
the pane 26, it would be desirable to cover the film 32 with a
protective coating or another transparent pane in order to guard
against scratches and other damage to the film 32. In alternative
embodiments, however, the film 32 may be applied to the outer
surface 30 of the pane 26, in which case a protective layer may not
be required for those aircraft window designs that employ one or
more additional panes between the outer surface 30 and the exterior
of the aircraft.
[0024] FIG. 4 is an aircraft window in accordance with another
embodiment of the invention. The window includes a transparent pane
36 having an inner and outer surface 38, 40. Disposed or embedded
within the pane 36 between its inner and outer surfaces 38, 40 is a
film that includes an electrically conductive material 42 that is
arranged in a pattern adapted to attenuate RF energy. Electrically
conductive material, such as copper, is used in the film, although
other embodiments may employ other metals, alloys, compositions,
etc. that are electrically conductive.
[0025] As shown in FIG. 4, the pattern used is a grid comprised of
generally square openings of dimensions, such as for example three
square centimeters, that have been found to be effective for
attenuating RF energy. In other embodiments, however, other
patterns may be used, such as a pattern comprised of generally
triangular openings or other fractal-derived shapes. In order to
better attenuate the RF energy, the conductive material 42 is
electrically grounded by use of a pigtail of the same material (not
shown), extending outwardly from a point on the perimeter of the
conductive material 42, and attached by conductive adhesive to any
convenient nearby point that is electrically connected to the skin
of the aircraft. In alternative embodiments, however, electrical
grounding can be accomplished by other means known in the art.
[0026] FIGS. 5 and 6 show an aircraft window in accordance with yet
another embodiment of the invention. As before, the window includes
a transparent pane 44 having an inner and outer surface 46, 48. In
this instance, however, a layer 50 of transparent conductive
material is applied to the inner surface 46. Originally in liquid
form, the conductive material is sprayed or brushed on the inner
surface 46, and then allowed to dry to a solid form which
constitutes the layer 50. The material that forms the layer 50 is
transparent to visible light but adapted to attenuate RF energy. An
exemplary material that would accomplish this is Lectrobase.TM.
which can be obtained from LVH Coatings Ltd., located in Coleshill,
UK. Basically this type of layer is constructed of polyurethane
resins containing dispersed electroconductive agents.
[0027] In order to better attenuate the RF energy, the layer 50 is
electrically grounded which is accomplished by use of strip of
electrically conductive film (not shown) secured to the window
perimeter and the inside of the aircraft skin by conductive
adhesive. Alternatively, electrical grounding can be accomplished
by overspraying of the window surround with the layer 50 material
so as to establish electrical continuity. In yet further
alternative embodiments, electrical grounding can be accomplished
by other means known in the art.
[0028] Because the layer 50 is applied to the inner surface 46 of
the pane 44, it would be desirable to cover the layer 50 with a
protective coating or another transparent pane in order to guard
against scratches and other damage to the layer 50. In alternative
embodiments, however, the layer 50 may be applied to the outer
surface 48 of the pane 44, in which case a protective layer may not
be required for those aircraft window designs that employ one or
more additional panes between the outer surface 48 and the exterior
of the aircraft.
[0029] In FIGS. 7 and 8, there is shown an aircraft window frame
56, a transparent pane 58, and a movable shade 60. The pane 58 is
disposed in the frame 60 and has an inner and outer surface. The
shade 60 is movable with respect to the frame 56 and is adapted to
cover the pane 58. (In FIG. 7, however, the shade 60 is shown in an
intermediate position.). Embedded within the shade 60 is a
conductive metal mesh 62 adapted to attenuate RF energy. The mesh
62 is constructed of fine copper wire. In other embodiments,
however, other conductive material could be used in lieu of the
copper wire mesh 62. The mesh 62 in the shade 60 is electrically
connected to ground by a pigtail of any suitably conductive braid
or wire (not shown), connected to any point that is electrically
connected to the aircraft skin. In alternative embodiments,
however, electrical grounding can be accomplished by other means
known in the art.
[0030] While the description above refers to particular embodiments
of the present invention, it will be understood that many
modifications may be made without departing from the spirit
thereof. The claims are intended to cover such modifications as
would fall within the true scope and spirit of the present
invention. The presently disclosed embodiments are therefore to be
considered in all respects as illustrative and not restrictive, the
scope of the invention being indicated by the claims rather than
the foregoing description and all changes which come within the
meaning and range of equivalency of the claims are therefore
intended to be embraced therein.
* * * * *