U.S. patent application number 12/427318 was filed with the patent office on 2010-02-18 for short range efficient wireless power transfer.
This patent application is currently assigned to NIGEL POWER, LLC. Invention is credited to Nigel P. Cook, Lukas Sieber, Hanspeter Widmer.
Application Number | 20100038970 12/427318 |
Document ID | / |
Family ID | 41217384 |
Filed Date | 2010-02-18 |
United States Patent
Application |
20100038970 |
Kind Code |
A1 |
Cook; Nigel P. ; et
al. |
February 18, 2010 |
Short Range Efficient Wireless Power Transfer
Abstract
A device is powered wirelessly using magnetically coupled
resonance, either from a short distance, e.g., on a surface, or
from or on a longer distance.
Inventors: |
Cook; Nigel P.; (El Cajon,
CA) ; Sieber; Lukas; (Olten, CH) ; Widmer;
Hanspeter; (Wohlenschwil, CH) |
Correspondence
Address: |
Law Office of Scott C Harris Inc
PO Box 1389
Rancho Santa Fe
CA
92067
US
|
Assignee: |
NIGEL POWER, LLC
San Diego
CA
|
Family ID: |
41217384 |
Appl. No.: |
12/427318 |
Filed: |
April 21, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61046757 |
Apr 21, 2008 |
|
|
|
Current U.S.
Class: |
307/104 |
Current CPC
Class: |
H02J 50/40 20160201;
H02J 50/12 20160201; H02J 50/60 20160201; H02J 7/0013 20130101 |
Class at
Publication: |
307/104 |
International
Class: |
H02J 17/00 20060101
H02J017/00 |
Claims
1. A system comprising: a magnetically coupled resonance system,
that includes a first surface against which devices to be provided
with power are located, and providing power at a first efficiency
of power transfer to said devices on said first surface, and
providing power at a second efficiency of power transfer, lower
than said first efficiency, to other devices that are not on said
first surface, each of said devices receiving said power using
magnetically coupled resonance between a transmitting antenna
adjacent said first surface, and a receiving antenna in at least
one device.
2. A system as in claim 1, wherein said system is tuned for maximum
efficiency on said first surface.
3. A system as in claim 1, wherein said transmitting antenna is
tuned for a thickness of a material of said first surface.
4. A system as in claim 1, wherein said devices which are not on
said first surface are inches away from said first surface.
5. A system as in claim 1, wherein said devices which are not on
said first surface are feet away from said first surface.
6. A system as in claim 1, wherein said first surface is integrated
into a desktop component.
7. A system as in claim 6, wherein said desktop component is a base
of a monitor.
8. A system as in claim 6, wherein said desktop component is a base
of a lamp.
9. A system as in claim 6, wherein said desktop component is a base
of a telephone charger.
10. A system as in claim 1, wherein said first surface is parallel
to a coil of an antenna in said first surface.
11. A system as in claim 1, further comprising a device which
allows detecting a proximity of a person, and terminating
transmission upon detecting said proximity of a person.
12. A system as in claim 11, wherein said device is switched on to
detect a proximity of the person, and switched off to transmit
power continuously.
13. A system comprising: a magnetically coupled resonance system,
that provides power to devices using magnetically coupled
resonance, a device, coupled to said magnetically coupled resonance
system, which allows detecting a proximity of a person, and
terminating transmission upon detecting said proximity of a
person.
14. A system as in claim 13, wherein said device is switched on to
detect the proximity of the person, and switched off to transmit
power continuously.
15. A system in claim 13, wherein said magnetically coupled
resonance system includes a first surface against which devices to
be charged are located, and providing power at a first efficiency
of power transfer to devices on said first surface, each of said
devices receiving said power using magnetically coupled resonance
between a transmitting antenna adjacent said first surface, and a
receiving antenna in at least one device.
16. A system in claim 15, wherein said magnetically coupled
resonance system further provides power at a second efficiency of
power transfer, lower than said first efficiency, to other devices
that are not on said first surface.
17. A system as in claim 16, wherein said system is tuned for
maximum efficiency on said first surface.
18. A system as in claim 16, wherein said transmitting antenna is
tuned for a thickness of a material of said first surface.
19. A system as in claim 16, wherein said devices which are not on
said first surface are less than 12 inches away from said first
surface.
20. A system as in claim 16, wherein said devices which are not on
said first surface are less than 3 feet away from said first
surface.
21. A system as in claim 16, wherein said first surface is
integrated into a desktop component.
22. A system as in claim 21, wherein said desktop component is a
base of a monitor.
23. A system as in claim 21, wherein said desktop component is a
base of a lamp.
24. A system as in claim 21, wherein said desktop component is a
base of a telephone charger.
25. A system as in claim 16, wherein said first surface is parallel
to a coil of an antenna in said first surface.
26. A method comprising: first powering a first device wirelessly,
using a magnetically coupled resonance system, by resting said
first device against a first surface against which devices to be
provided with power are located, said first powering providing
power at a first efficiency of power transfer to devices on said
first surface; second powering a second device wirelessly, at a
second efficiency of power transfer, lower than said first
efficiency, said second device not being on said first surface,
each of said second devices receiving said power using magnetically
coupled resonance between a transmitting antenna adjacent said
first surface, and a receiving antenna in at least one device.
27. A system comprising: a magnetically coupled resonance system,
that includes a first surface against which devices to be provided
with power are located, said resonance system including a repeater
antenna, adjacent said surface, which repeats magnetically
resonantly received power over a whole area of said first surface,
thereby converting the whole desktop into a charging system.
28. A system as in claim 27, further comprising a magnetic
transmitter, separated from said repeater antenna, and tuned to
resonance with said repeater antenna.
29. A system as in claim 27, wherein said repeater antenna is
integrated into a desktop component.
30. A system as in claim 29, wherein said desktop component is a
base of a monitor.
31. A system as in claim 29, wherein said desktop component is a
base of a lamp.
32. A system as in claim 29, wherein said desktop component is a
base of a telephone charger.
33. A system as in claim 27, wherein said first surface is parallel
to a coil of an antenna in said first surface.
34. A system as in claim 27, further comprising a device which
allows detecting a proximity of a person, and terminating
transmission upon detecting said proximity of a person.
35. A system as in claim 27, wherein said device is switched on to
detect a proximity of the person, and switched off to transmit
power continuously.
36. A system comprising: a magnetically coupled resonance system,
that includes a first repeater antenna resonant with a first
frequency, which repeats magnetically resonantly received power at
said first frequency in an area of said first repeater antenna, and
a second repeater antenna, spaced from said first repeater antenna
and resonant with a first frequency, which repeats magnetically
resonantly received power at said first frequency in an area of
said second repeater antenna.
37. A system as in claim 36, further comprising a first surface
against which devices to be provided with power are located, said
first surface being adjacent said second repeater antenna.
38. A system as in claim 37, wherein said first surface is a
desktop, and the whole desktop is used as a charging system.
39. A system as in claim 36, further comprising a magnetic
transmitter, separated from said repeater antenna, and tuned to
resonance with said repeater antenna.
40. A system as in claim 39, wherein said repeater antenna is
integrated into a desktop component.
41. A system as in claim 40, wherein said desktop component
comprises a base of a monitor.
42. A system as in claim 40, wherein said desktop component
comprises a base of a lamp.
43. A system as in claim 40, wherein said desktop component
comprises a base of a portable electronic device charger.
44. A system as in claim 36, wherein said first surface is parallel
to a coil of an antenna in said first surface.
45. A system as in claim 36, further comprising a device which
allows detecting a proximity of a person, and terminating
transmission upon detecting said proximity of a person.
46. A system as in claim 36, wherein said system is switched on to
detect a proximity of the person, and switched off to transmit
power continuously.
47. A system as in claim 40, wherein said portable electronic
device comprises a cellular communication device.
48. A system comprising: a magnetically coupled resonance system,
that includes a transmitter antenna resonant with a first
frequency, which transmits magnetically resonant power at said
first frequency and a repeater antenna, spaced from said
transmitter antenna and resonant with said first frequency, which
repeats magnetically resonantly received power at said first
frequency in an area of said repeater antenna, wherein said
transmitter antenna and said repeater antenna are the same
size.
49. A system comprising: a magnetically coupled resonance system,
that includes a transmitter antenna resonant with a first
frequency, which transmits magnetically resonant power at said
first frequency and a repeater antenna, spaced from said
transmitter antenna and resonant with said first frequency, which
repeats magnetically resonantly received power at said first
frequency in an area of said repeater antenna, wherein said
transmitter antenna is larger in its overall size than said
repeater antenna.
50. A system as in claim 49, wherein said transmitter antenna has a
larger diameter than said repeater antenna.
Description
[0001] This application claims priority from provisional
application 61/046,757, filed Apr. 21, 2008, the entire contents of
which are herewith incorporated by reference.
BACKGROUND
[0002] Our previous applications and provisional applications,
including, but not limited to, U.S. patent application Ser. No.
12/018,069, filed Jan. 22, 2008, entitled "Wireless Apparatus and
Methods", the entire contents of the disclosure of which is
herewith incorporated by reference, describe wireless transfer of
power between a transmitter and receiver.
[0003] The transmit and receiving antennas are preferably resonant
antennas, which are substantially resonant, e.g., within 10% of
resonance, 15% of resonance, or 20% of resonance. The antenna may
be of a small size to allow it to fit into a mobile, handheld
device where the available space for the antenna may be limited. An
embodiment describes a high efficiency antenna for the specific
characteristics and environment for the power being transmitted and
received.
[0004] One embodiment uses an efficient power transfer between two
antennas by storing energy in the near field of the transmitting
antenna, rather than sending the energy into free space in the form
of a travelling electromagnetic wave. This embodiment increases the
quality factor (Q) of the antennas. This can reduce radiation
resistance (R.sub.r) and loss resistance (R.sub.l).
[0005] The inventors noticed that many of the solutions raised by
this system include power delivery at a distance, for example power
delivery over inches or feet from a power transmitter to a
receiver. The techniques disclosed in our co-pending applications
allow delivery of power at reasonable efficiencies, for example
between 3 and 5 feet, for example, and efficiencies from 5 to
40%.
SUMMARY
[0006] However, it was noticed that many users and/or manufacturers
would actually prefer higher power-delivery efficiencies, and are
willing to accept this power delivery at short distances. For
example, many would prefer a power delivery solution which was over
90% efficient, even if that power delivery solution was less
convenient to use. The inventors noticed that the resonant which
have been used for delivery of power at a distance, could actually
be used to produce very high efficiencies when used in a close
contact situation.
[0007] An aspect describes a magnetically coupled resonance system,
that includes a first pad surface against that accepts devices to
be provided with power. The device uses the magnetically coupled
resonance to provide power at a first efficiency of power transfer
to devices on the pad surface. Power is provided at a second
efficiency of power transfer, lower than said first efficiency, to
other devices that are not on said first surface, e.g., devices
that are remote from the pad by e.g., less than 12 inches or less
than 3 feet.
[0008] The devices and pad can each use magnetically resonant
circuits with antennas formed of an inductor formed by a coil, and
a separate capacitor, tuned to an appropriate frequency.
[0009] The present application discloses use of these techniques to
form a wireless desktop. The wireless desktop can be used to charge
personal electronic devices such as communications terminals,
cellular phones, or computer based peripheral devices these charged
devices are either or both of powered or recharged, without wires,
using a wireless energy transfer technique.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a wireless desktop with wireless powered
items;
[0011] FIG. 2 shows an equivalent circuit;
[0012] FIGS. 3A-3F show single receivers on pads with and without
foldouts;
[0013] FIG. 4 shows efficiencies for the single receivers;
[0014] FIGS. 5A-5D show pads with multiple receivers;
[0015] FIG. 6 shows transfer efficiencies for the multiple
receivers;
[0016] FIG. 7 shows coplanar field coupling using parasitic;
and
[0017] FIG. 8 shows a desktop parasitic.
DETAILED DESCRIPTION
[0018] An embodiment uses coupled magnetic resonance using magnetic
field antennas. Embodiments may operate at any frequency, but two
embodiments may operate either at LF (e.g. 135 kHz) or at HF (e.g.
13.56 MHz), but at short distances. One embodiment uses a loop coil
in series with a capacitor as the antenna. In one embodiment, the
receiver part (e.g., the portable device) is intended to be placed
directly on the pad. In this embodiment, there is a relatively
small, fixed distance between the transmitter and receiver. That
fixed distance, for example, may be set by the thickness of the
material of the pad and the material of the housing. This may be
less than a centimeter or less than 10 mm, between the coils
forming the transmitter and receiver. The distance will be
constant, so the item is always the same distance from the antenna
when pressed against the pad.
[0019] That fixed distance is dependent on the geometry of the pad
and the geometry of the charged item. In the embodiment, the
antenna can be tuned to have a maximum response at that constant
distance. This tuning, as well as other tuning operations described
in this specification, can be calculated and then optimized by
trial and error, for example.
[0020] However, unlike other close-charging systems, this system
can also charge items which are located at a distance, e.g., inches
or feet from the antenna. The antenna is less efficient when
charging at a distance, but will still provides power at that
distance. That allows charging of items that are not directly
placed on the charging pad - unlike pure inductive systems which
provide in essence no charge at all other than at the very specific
fixed distance and/or orientation.
[0021] This produces certain advantages, including the ability to
use less precision in the placement of the device on the charging
pad. Even if the device is placed off the pad, it will still
receive charging at a lower level from proximity. The lower level
charge can be, for example, between 0.05 watts and 0.25 watts, for
example, even when the device is not precisely placed on the
pad.
[0022] To utilize desktop space efficiently and to reduce desktop
wiring, the antenna of the power transmitter/power base may be
incorporated into a host device that normally exists on a desktop.
Embodiments describe that host device as including either a PC
monitor or a lamp, but can be any other item, such as a printer,
scanner, fax machine, telephone, router, or the like.
[0023] The transmitter unit may be powered directly from the
110/230 VAC supply already existing in this host device, thus not
requiring an extra power cord or power connection.
[0024] In one embodiment, as shown in FIG. 1, the transmit antenna
is embedded in the pedestal 104 of a PC monitor screen 100 or in
the pedestal 112 of a desk lamp 110. The pedestals may be
disk-shaped, to house a circular wire loop antenna generating a
symmetric magnetic field. This field is mostly vertically polarized
at any position on the desk, in the plane of the antenna loop. This
embodiment favors coplanar orientation of antenna loops integrated
in wireless-power-enabled devices; that is, the best power-transfer
will be obtained when a loop coil in the receiving device is
oriented in a substantially parallel plane to a loop coil in the
transmitting device. The surface of the charging base may be
substantially parallel with the coil, so that the coplanar
relationship can be maintained. FIG. 7 illustrates how the coplanar
operation can extend to all the items on the desktop.
[0025] This coplanar orientation can be used, for example, for wire
loop antennas integrated into keyboards, mouse devices, and into
many other electronic devices such as mobile phones, MP3 players,
PDAs, etc. if placed in the usual manner. This may, however, be
used in other applications.
[0026] In another embodiment, there may be more than one power base
on a desktop as shown in FIG. 1. Power is supplied from the base
that is closest to the receiving device or from multiple different
sources.
[0027] Each power base may also provide an area to place devices
directly on the wire loop antenna, resulting in strongest coupling,
thus enabling high power transfer at high efficiency. This close
proximity coupling is attained by providing a surface 105, for
example, adjacent the charging coil. In this embodiment, more than
one device may be placed on such a charging pad surface 105. This
has the other advantage of allowing a larger coil for the
transmitting, which also provides improved efficiency.
[0028] Low power devices with long battery autonomy, such as a
keyboard or a computer mouse, may be placed in the proximity or
vicinity of a power base to charge by proximity coupling. Available
power and transfer efficiency for these devices will be lower than
for the fixed distance coupling. However, these devices may be
constantly charged, and intermittently used. Hence, these devices
do not require continuous charging. In one embodiment, the amount
of charging may be reduced when other devices are additionally
placed on the charging pad, because the multiple devices may more
heavily load the system than a single device.
[0029] Magnetic field strength in the vicinity of a power base will
preferably be below safety critical levels. The power base may
additionally provide a function to automatically reduce magnetic
field strength if a person is approaching. This function may use
infrared or microwave person detection 108. This can be a proximity
detector, e.g., one that can be activated by user proximity.
[0030] A first embodiment actuates the proximity detector manually.
Persons that feel uncomfortable in presence of magnetic fields can
turn on the function. This function will can also cause devices in
the vicinity to stop receiving power during the time when persons
are in proximity. This may use, for example, an IR detector to
detect the presence of persons.
[0031] Another embodiment may always have the proximity detector
active and automatically turn off the function when
[0032] Other devices such as cordless phones, digicams, etc. may be
placed on a charging station. This allows the wireless power
receiver and its antenna to be made an integral part of the
recharging station. A charging station may provide more area and/or
space to integrate an efficient power receiver other than the
portable device itself. For example, this may use electrical
contacts, or by using a wireless technique or a wireless parasitic
antenna, as described herein. The charging station itself may be
configured and used as a power relay or a parasitic antenna that
improves coupling between the transmitter and the portable devices
which receive the charge.
[0033] In an embodiment, shown in FIG. 1, there may be a number of
different electrically operated devices on a user's "desktop",
which may be items used by a user for work every day. One such item
is a monitor 100 for a PC. This operates off power provided by a
110 V connection 102 which plugs into the AC outlet. The 110 V
connection 100 provides power for both the operation of the
monitor, and also provides the power for the wireless surface 104
that is integrated into the base of the monitor. The charging pad
may use the techniques that are described in detail herein.
[0034] Wireless proximity charging may be enabled in the area 105,
which forms a flat surface on the base. According to this
embodiment, the wireless proximity charging may be specifically
tuned for short distance connections, although it may also operate
properly over longer distance connections. Surface 105 may be sized
such that devices such as cell phones and PDAs such as 107 may be
rested on the surface. While charging is optimized for the area
105, charging is still carried out in other areas.
[0035] In this embodiment, there is also another charging base as
part of a desk lamp 110. This forms a charging base 112 with an
area 113 thereon. As in the 104 charging base, the charging is
optimized for carrying out up close proximity charging of items
such as 114 using magnetically coupled resonance. It may also
charge items that are distant from the charging base.
[0036] In addition to charging items such as 114 on the charging
base, either or both of the items produces magnetically resonant
output power that is coupled to remote devices that are enabled for
wireless charging. These remote devices, for example, may include a
magnetically resonant antenna therein that is resonant to the same
frequency of the transmission. In an embodiment, this may be at
13.56 MHz or at 135 Khz, or at any other frequency.
[0037] The charged devices can include a digital camera 121, a
wireless mouse 122, and a wireless keyboard 123. Each of these
devices, for example, can include a battery therein, which is
charged by the operation of the device.
[0038] An important feature is that an up close charge can be
carried out at high efficiency, or a distance charge can be carried
out lower efficiency.
[0039] FIG. 2 shows an equivalent circuit of the power transmission
system, and illustrates how the efficiency can be calculated. A
power source 200 portion includes a power source 205, for example
the AC socket. The power source 205 has an equivalent loss
resistance 210. The loss resistance 210 models the resistance and
power conversion losses. Alternatively, the power source can
include some parts of the conversion electronics, for example in
the case that the power from the power source is changed to some
other frequency or some other power value.
[0040] The power source 205 is connected across terminals 215, to
antenna part 220. Antenna includes an inductor 230 and series
capacitance 235. The LC constant of the inductor and capacitance is
tuned to be substantially at the frequency of the source 205. The
antenna also has shows a loss resistance value 235, which is a
parasitic value that represents the transmit antenna losses,
including internal losses, external losses, and radiation
losses.
[0041] A magnetic field 250 is created in the vicinity of the
antenna 230. This is coupled to the antenna 240 of the receiver. As
in the antenna 230, the antenna 240 includes an inductor 242
capacitor 244. The inductor and capacitor form a circuit that is
resonant with the received frequency that is received.
[0042] Receive antenna losses are shown by the series resistance
246. The input power P.sub.r is connected via the terminals 248 to
a load 260. The load 260 also includes receive power losses 262
shown as a series resistance, which can be modeled as losses in the
system.
[0043] These losses can include the power conversion losses as well
as series resistance losses.
[0044] Another system can attempt to obtain maximum efficiency in
various different scenarios. For example, in one scenario, the
transmit antenna can be tuned by changing the capacitance to obtain
resonance at the operating frequency in the presence of an unloaded
receiver. In an unloaded receiver scenario, the resistance of the
load is infinite. Loaded receivers change this resistance. Receiver
measurements can also be carried out, by tuning the receiving
antenna to change the capacitance etc. in the presence of an
unloaded transmitter or in the case of multiple transmitters.
[0045] The different values can be measured. Capacitance value
adjustments can be available, for example, for unloaded, moderately
loaded (e.g, a single load) or highly loaded systems. Different
capacitance values can be dynamically switched to create the
highest efficiency value, and to operate with that value.
[0046] FIGS. 3A-3F show different scenarios of charging. FIG. 3A
shows a conventional PDA 300 on a large charging pad 305. In the
embodiment, this may be a low-frequency charging pad which may have
a 26 cm diameter. Another embodiment may use a PDA 310 which
includes a foldout antenna portion 315. The foldout antenna portion
315 may include a loop antenna that can be folded away from the
body of the device to improve the coupling efficiency.
[0047] FIG. 3C shows a small pad embodiment, where the pad 320 is
substantially the same size as the PDA 300. In this embodiment, the
pad may be 6.times.9 cm. FIG. 3B shows how this pad might be used
with a foldout embodiment, where the flap 315 fits directly over
the pad 320. A medium pad is shown in FIGS. 3E and 3F. In this
embodiment, the medium pad 330 includes the PDA 300 thereon, or a
foldout PDA 310 with its foldout flat. The medium pad may be 18 cm
in diameter in this embodiment.
[0048] The efficiency results for these devices are shown in FIG.
4, which shows how the different size devices can be located on the
different size pads. Five of the six situations have efficiencies
which are greater than 80%. Even the lowest efficiency, created by
a large pad with an integrated receiver in the phone, had a
transfer efficiency of 50%.
[0049] Another embodiment shown in FIGS. 5A-5D may use multiple
receivers all on the same pad. Since the pads, especially the large
and medium pads, have sizes that are large enough to physically
hold multiple different phones, multiple different devices can be
placed all on the pad.
[0050] FIGS. 5A-5D illustrates these different embodiments. In FIG.
5A, the pad 305 includes three PDA phones/devices thereon, shown as
400, 402 and 404; however, the pad may include more or fewer
devices.
[0051] In the FIG. 5B embodiment, the devices have foldout
antennas, with the devices 510, 512 and 514 each representing a PDA
on the pad, along with its foldout flat against the pad and away
from the body of the phone.
[0052] FIG. 5C shows the medium pad 330 with two phones thereon,
400, 402, while FIG. 5B shows this same pad with two foldouts
thereon 510, 512.
[0053] FIG. 6 shows the measured efficiency of this system, with
again most of the efficiencies being greater than 80%.
[0054] The efficiency of the system .eta..sub.a can be calculated
as the input power across the terminals 215 divided by receive
power across the terminals 248
[0055] or .eta..sub.a=P.sub.r/P.sub.t.
[0056] Another embodiment shown in FIG. 8 forms a power relay as a
parasitic antenna that improves coupling between energy source and
energy sink. The energy source is formed of a resonant antenna 810,
which may be a resonant capacitor and inductor. A parasitic antenna
800, which may also be resonant at the same frequency, may be used.
This parasitic antenna may be expanded to cover a large portion of
the desktop area 820 as shown. Such a parasitic loop may either be
mounted beneath the desk, or built into the desktop surface, or put
on the desk's surface e.g. as a flat structure, such as a desk mat.
The parasitic device can be excited by a single and small active
power base, and can be used to dramatically improve performance and
efficiency of wireless desktop powering and charging in that
area.
[0057] Inductive excitation from a small power base may however be
a convenient solution since it does not require integration of any
part. This becomes particularly true when the parasitic antenna is
invisibly integrated into the desktop. FIG. 8 illustrates a large
parasitic loop thereby improving the coupling between power base
and receiver devices. The parasitic loop can cover an entire desk
surface, providing a hot zone throughout that desk surface. The
parasitic antenna, in this embodiment, provides passive repeating
of power to the entire desktop area.
[0058] The same kind of antenna, in another embodiment, may also be
driven directly from a transmitter unit.
[0059] The general structure and techniques, and more specific
embodiments which can be used to effect different ways of carrying
out the more general goals are described herein.
[0060] Although only a few embodiments have been disclosed in
detail above, other embodiments are possible and the inventors
intend these to be encompassed within this specification. The
specification describes specific examples to accomplish a more
general goal that may be accomplished in another way. This
disclosure is intended to be exemplary, and the claims are intended
to cover any modification or alternative which might be predictable
to a person having ordinary skill in the art.
[0061] Also, the inventors intend that only those claims which use
the words "means for" are intended to be interpreted under 35 USC
112, sixth paragraph. Moreover, no limitations from the
specification are intended to be read into any claims, unless those
limitations are expressly included in the claims.
[0062] Where a specific numerical value is mentioned herein, it
should be considered that the value may be increased or decreased
by 20%, while still staying within the teachings of the present
application, unless some different range is specifically mentioned.
Where a specified logical sense is used, the opposite logical sense
is also intended to be encompassed.
* * * * *