U.S. patent application number 09/900422 was filed with the patent office on 2001-11-08 for clear fluid ink-jet pen alignment.
Invention is credited to Daniel, Burton, Elgee, Steven B., Lund, Mark D..
Application Number | 20010038399 09/900422 |
Document ID | / |
Family ID | 23497598 |
Filed Date | 2001-11-08 |
United States Patent
Application |
20010038399 |
Kind Code |
A1 |
Lund, Mark D. ; et
al. |
November 8, 2001 |
Clear fluid ink-jet pen alignment
Abstract
A method and apparatus for a test pattern used in the alignment
of an ink-jet pen which deposits fixer fluid, or other clear ink
precursor fluid, on print media uses the change in reflectivity
caused by overprinting a series of positional-calibration indicia
with colorant to obtain data with respect to deviations in a
carriage-scan x-axis and a paper scan y-axis. Thus the invention
measures distances between pens or nozzles.
Inventors: |
Lund, Mark D.; (Vancouver,
WA) ; Daniel, Burton; (Vancouver, WA) ; Elgee,
Steven B.; (Portland, OR) |
Correspondence
Address: |
HEWLETT-PACKARD COMPANY
Intellectual Property Administration
P. O. Box 272400
Fort Collins
CO
80527-2400
US
|
Family ID: |
23497598 |
Appl. No.: |
09/900422 |
Filed: |
July 6, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09900422 |
Jul 6, 2001 |
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09379521 |
Aug 23, 1999 |
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Current U.S.
Class: |
347/19 |
Current CPC
Class: |
B41J 2/2114 20130101;
B41J 29/393 20130101; B41J 2/2135 20130101; B41J 2/125
20130101 |
Class at
Publication: |
347/19 |
International
Class: |
B41J 029/393 |
Claims
What is claimed is:
1. A method for determining positional correction factors for at
least one ink-jet clear fluid writing instrument and at least one
ink-jet colorant writing instrument respectively mounted for
printing on an adjacently positioned print medium and using a
predetermined pattern of printing, comprising the steps of:
mounting the ink-jet clear fluid writing instrument and ink-jet
colorant writing instrument in predetermined fixed positions
relative to each other for printing pixels on the adjacently
positioned print medium; mounting an optical sensing device in a
predetermined fixed position relative to the ink-jet clear fluid
writing instrument and ink-jet colorant writing instrument;
printing a first predetermined pattern in predetermined target
regions on a blank print medium by firing from one writing
instrument; printing a second predetermined pattern on the print
medium by firing from the other writing instrument such that first
regions of print occur superjacent the first predetermined pattern
and second regions of print occur substantially adjacent the first
regions such that the first regions wherein the first and second
regions have differences in reflectivity recognizable by the
optical sensing device; sensing the first regions and the second
regions with the optical sensing device to obtain data
representative of the differences in reflectivity; and determining
positional difference between the first regions and the second
regions compared to predetermined target regions positions of the
first predetermined pattern.
2. The method as set forth in claim 1, the step of printing a first
predetermined pattern in predetermined target regions on a blank
print medium by firing from one writing instrument further
comprises: depositing clear fluid droplets from the ink-jet clear
fluid writing instrument.
3. The method as set forth in claim 2, wherein the step of printing
a second predetermined pattern on the print medium by firing from
the other writing instrument such that first regions of print occur
superjacent the first predetermined pattern and second regions of
print occur substantially adjacent the first regions such that the
first regions and the second regions have differences in
reflectivity recognizable by the optical sensing device further
comprises; depositing droplets from the ink-jet colorant writing
instrument.
4. The method as set forth in claim 1, the step of printing a first
predetermined pattern comprising the step of: scanning the ink-jet
clear fluid writing instrument across the print medium and firing
clear fluid droplets toward predetermined target pixels to form a
pattern of a series of positional-calibration indicia.
5. The method as set forth in claim 4, the step of printing a first
predetermined pattern further comprising the step of: forming one
series of positional-calibration indicia for each ink-jet colorant
writing instrument.
6. The method as set forth in claim 5, the step of printing a
second predetermined pattern comprising the step of: printing a
respective band of colorant over and between each respective series
of positional-calibration indicia from each the respective ink-jet
colorant writing instrument.
7. A test pattern for aligning a clear fixer printhead of a first
ink-jet pen firing drops of a clear fixer to a printhead of a
second ink-jet pen firing drops of colorant, comprising: at least
one series of positional-calibration indicia of clear fixer formed
on a print medium by the first ink-jet pen; and at least one
colorant deposited on the series of positional-calibration indicia
of clear fixer and on regions of the print medium adjacent to the
indicia, wherein the indicia having colorant deposited thereon and
the regions of the print medium adjacent to the indicia have
different coefficients of reflectivity.
8. The test pattern as set forth in claim 7, comprising: the
positional-calibration indicia provide data obtained with respect
to corrections for deviations in a x-axis and a y-axis.
9. An apparatus for aligning a clear fixer printhead of a first
ink-jet pen firing drops of a clear fixer to printheads of at least
one ink-jet pen firing drops of color ink, comprising: optical
sensor means for projecting light and receiving light to which the
clear fixer is optically unrecognizable when deposited on blank
print media, wherein the color ink has a reflectivity that is
optically recognizable when compared to the blank print media;
means for exposing the print media to the optical sensor while the
sensor is operated; first printhead means for printing a
predetermined fractional fill pattern on a first region with the
first ink-jet pen firing drops of the clear fixer; second printhead
means for printing on the print media with color ink from the at
least one ink-jet pen firing drops of color ink both superjacent
onto the fractional fill pattern and region adjacent the fractional
fill pattern on the blank print media such that bleed of the clear
fixer with the superjacent color ink converts the fractional fill
pattern into a fill pattern that has a different reflectivity than
the regions adjacent the fractional fill pattern; and means for
comparing data representative of the predetermined fractional fill
pattern to the actual position of the first region.
10. The apparatus as set forth in claim 9, comprising: the means
for exposing the print media includes a mounting wherein the first
ink-jet pen and the at least one ink-jet pen firing drops of color
ink are fixedly mounted and the sensing means are fixedly aligned
in a predetermined relationship to each other.
11. The apparatus as set forth in claim 9, comprising: the mounting
is a scanning carriage for carrying the first ink-jet pen and the
at least one ink-jet pen firing drops of color ink across
predetermined swath positions of the print medium.
12. The apparatus as set forth in claim 10, the means for comparing
data representative of the predetermined fractional fill pattern to
the actual position of the first region comprising: means for
relating data obtained by the sensor with respect to corrections
for deviations in a carriage-scan x-axis and a paper scan
y-axis.
13. An ink-jet pen hard copy apparatus for depositing droplets of
marking fluid on targeted pixels of a print media, comprising:
first printing means for printing a clear fluid on a print medium
in a print zone of the apparatus; second printing means for
printing ink on the print medium in the print zone of the
apparatus; determining means for determining presence of print on
the print medium, including an optical sensing means for directing
light onto the print medium and detecting reflections of the light
from the print medium wherein the determining means senses
reflectivity differences between ink on the print medium and ink
overlaid on the clear fluid on the print medium; and positioning
means for locating particular regions of patterns printed by the
first printing means and second printing means, the patterns having
both regions of ink on the print medium and regions of ink overlaid
on the clear fluid on the print medium.
14. The apparatus as set forth in claim 13, comprising: the clear
fluid is an ink fixer; the first printing means is an ink-jet fixer
printhead for firing droplets of fixer onto targeted pixels of the
print medium; the second printing means is a plurality of ink-jet
inking printheads, each firing droplets of a different colorant
onto targeted pixels of the print medium, wherein the fixer
printhead and the inking printheads are fixedly mounted with
respect to each other in predetermined positions in a printhead
scanning carriage associated with a positional encoder.
15. The apparatus as set forth in claim 14, comprising: the optical
sensing means includes an light emitting diode for emitting a
predetermined wavelength light selected for determining
reflectivity each different colorant; the determining means
includes a fixed mounting for the optical sensing means wherein the
optical sensing means is fixedly mounted with respect to the fixer
printhead and the inking printheads in a predetermined position in
the printhead scanning carriage associated with the positional
encoder.
16. The apparatus as set forth in claim 13, the patterns further
comprising: at least one series of positional-calibration indicia
of clear fixer formed on a print medium by the first ink-jet pen;
and at least one colorant deposited on the series of
positional-calibration indicia of clear fixer and on regions of the
print medium adjacent to the indicia, wherein the indicia having
colorant deposited thereon and the regions of the print medium
adjacent to the indicia have different coefficients of
reflectivity.
17. The apparatus as set forth in claim 16, comprising: the
positional-calibration indicia provide data obtained with respect
to corrections for deviations in a carriage-scan x-axis and a paper
scan y-axis.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to ink-jet printing
technology methods and apparatus and, more specifically, to a
method and apparatus for aligning ink-jet pens firing droplets of a
clear fluid.
[0003] 2. Description of the Related Art
[0004] The art of ink-jet technology is relatively well developed.
Commercial products such as computer printers, graphics plotters,
copiers, and facsimile machines employ ink-jet technology for
producing hard copy. The basics of this technology are disclosed,
for example, in various articles in the Hewlett-Packard Journal,
Vol. 36, No. 5 (May 1985), Vol. 39, No. 4 (August 1988), Vol. 39,
No. 5 (October 1988), Vol. 43, No. 4 (August 1992), Vol. 43, No. 6
(December 1992) and Vol. 45, No. 1 (February 1994) editions.
Ink-jet devices are also described by W. J. Lloyd and H. T. Taub in
Output Hardcopy [sic] Devices, chapter 13 (Ed. R. C. Durbeck and S.
Sherr, Academic Press, San Diego, 1988).
[0005] In U.S. Pat. No. 5,635,969 (Allen, assigned to the common
assignee of the present invention and incorporated herein by
reference), METHOD AND APPARATUS FOR THE APPLICATION OF MULTIPART
INK-JET INK CHEMISTRY, a multi-color ink-jet printing system
includes a printing element for apply a precisely metered quantity
of a colorless precursor to a recording medium surface. The
precursor conditions the medium surface prior to application of one
or more colorants to the recording medium surface to prevent cockle
and curl and to reduce dry time, while conditioning the recording
medium surface for uniform dot gain independent of media
composition. U.S. patent application Ser. No. 09/069,717, entitled
REACTIVE INK SET FOR INK-JET PRINTING, by Askeland et al., and U.S.
patent application Ser. No. 09/069,616, entitled MULTI-CHAMBER
FLUID SUPPLY, by Askeland et al., and Related Applications cited
therein are also assigned to the common assignee of the present
invention and are incorporated herein by reference. Hereinafter,
clear fluids used to affect ink dry time and permanence and to
prevent cockle and curl of the print medium are generically
referred to as "fixers."
[0006] In U.S. Pat. No. 5,600,350 (Cobbs et al., assigned to the
common assignee of the present invention and incorporated herein by
reference), MULTIPLE INKJET PRINT CARTRIDGE ALIGNMENT BY SCANNING A
REFERENCE PATTERN AND SAMPLING SAME WITH REFERENCE TO A POSITION
ENCODER, a method and apparatus for multiple ink-jet print
cartridge alignment is provided by scanning a reference pattern and
sampling with an optical sensor. In effect, a given test pattern is
printed and actual print image data is compared to determine any
misregistration of the cartridges. A SYSTEM AND METHOD FOR
ESTABLISHING POSITIONAL ACCURACY IN TWO DIMENSIONS BASED ON A
SENSOR SCAN IN ONE DIMENSION, also to the common assignee herein
and incorporated by reference, is provided in U.S. Pat. No.
5,796,414 (Sievert et al.).
[0007] While the method of printing a test pattern and optically
detecting actual positions of element of the pattern on the print
media provides a valuable tool for colorants that have a sufficient
reflectivity difference with respect to the background media, a
problem arises with colorants that have a reflectance only a few
percent different than the reflectance of the blank media. In U.S.
patent application Ser. No. 08/636,439, for SYSTEMS AND METHOD FOR
DETERMINING PRESENCE OF INKS THAT ARE INVISIBLE TO SENSING DEVICES
(Nelson et al., assigned to the common assignee of the present
invention and incorporated herein by reference), a system and
method for determining the presence of inks that are visible to the
normal human eye, but optically "invisible" to sensors is
provided.
[0008] There remains a need for a method and apparatus for aligning
an ink-jet print cartridge which prints a clear fluid on the print
medium
SUMMARY OF THE INVENTION
[0009] In its basic aspects, the present invention provides a
method for determining positional correction factors for at least
one ink-jet clear fluid writing instrument and at least one ink-jet
colorant writing instrument respectively mounted for printing on an
adjacently positioned print medium and using a predetermined
pattern of printing. The process includes the steps of: mounting
the ink-jet clear fluid writing instrument and ink-jet colorant
writing instrument in predetermined fixed positions relative to
each other for printing pixels on the adjacently positioned print
medium; mounting an optical sensing device in a predetermined fixed
position relative to the ink-jet clear fluid writing instrument and
ink-jet colorant writing instrument; printing a first predetermined
pattern in predetermined target regions on a blank print medium by
firing from one writing instrument; printing a second predetermined
pattern on the print medium by firing from the other writing
instrument such that first regions of print occur superjacent the
first predetermined pattern and second regions of print occur
substantially adjacent the first regions such that the first
regions wherein the first and second regions have differences in
reflectivity recognizable by the optical sensing device; sensing
the first regions and the second regions with the optical sensing
device to obtain data representative of the differences in
reflectivity; and determining positional difference between the
first regions and the second regions compared to predetermined
target regions positions of the first predetermined pattern.
[0010] In another basic aspect, the present invention provides a
test pattern for aligning a clear fixer printhead of a first
ink-jet pen firing drops of a clear fixer to a printhead of a
second ink-jet pen firing drops of colorant, including: at least
one series of positional-calibration indicia of clear fixer formed
on a print medium by the first ink-jet pen; and at least one
colorant deposited on the series of positional-calibration indicia
of clear fixer and on regions of the print medium adjacent to the
indicia, wherein the indicia having colorant deposited thereon and
the regions of the print medium adjacent to the indicia have
different coefficients of reflectivity.
[0011] In another basic aspect the present invention provides an
apparatus for aligning a clear fixer printhead of a first ink-jet
pen firing drops of a clear fixer to printheads of at least one
ink-jet pen 115 firing drops of color ink, including: optical
sensor devices for projecting light and receiving light to which
the clear fixer is optically unrecognizable when deposited on blank
print media, wherein the color ink has a reflectivity that is
optically recognizable when compared to the blank print media;
mechanisms for exposing the print media to the optical sensor while
the sensor is operated; a first printhead for printing a
predetermined fractional fill pattern on a first region with the
first ink-jet pen firing drops of the clear fixer; a second
printhead for printing on the print media with color ink from the
at least one ink-jet pen firing drops of color ink both superjacent
onto the fractional fill pattern and region adjacent the fractional
fill pattern on the blank print media such that bleed of the clear
fixer with the superjacent color ink converts the fractional fill
pattern into a fill pattern that has a different reflectivity than
the regions adjacent the fractional fill pattern; and mechanisms
for comparing data representative of the predetermined fractional
fill pattern to the actual position of the first region.
[0012] In another basic aspect the present invention provides an
ink-jet pen hard copy apparatus for depositing droplets of marking
fluid on targeted pixels of a print media, including: a first
printing mechanism for printing a clear fluid on a print medium in
a print zone of the apparatus; a second printing mechanism for
printing ink on the print medium in the print zone of the
apparatus; a determining mechanism for determining presence of
print on the print medium, including an optical sensing means for
directing light onto the print medium and detecting reflections of
the light from the print medium wherein the determining means
senses reflectivity differences between ink on the print medium and
ink overlaid on the clear fluid on the print medium; and a
positioning mechanism for locating particular regions of patterns
printed by the first printing means and second printing means, the
patterns having both regions of ink on the print medium and regions
of ink overlaid on the clear fluid on the print medium.
[0013] It is an advantage of the present invention that it provides
a method and apparatus for optically determining deposits of clear
fluid without resorting to ultraviolet, infrared, flourescent, or
the like specialized mechanisms for sensing.
[0014] It is an advantage of the present invention that it provides
a solution that does not require additional components to be
incorporated into an ink-jet hard copy apparatus.
[0015] It is another advantage of the present invention that by
using existing product devices, manufacturing costs are not
increased.
[0016] It is another advantage of the present invention that by
using existing product devices it reduces the potential of added
complexity and attendant lowering of reliability.
[0017] It is another advantage of the present invention that it
permits the manufacture of products having a minimized size.
[0018] It is another advantage of the present invention that it
provides a product adaptable to a plurality of functional
designs.
[0019] Other objects, features and advantages of the present
invention will become apparent upon consideration of the following
explanation and the accompanying drawings, in which like reference
designations represent like features throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of an ink-jet printer in
accordance with the present invention.
[0021] FIG. 2 is an optical sensing unit used in accordance with
the present invention as shown in FIG. 1.
[0022] FIG. 3 is a test pattern for scanning with the optical
sensing unit as shown in FIG. 2 and as used in accordance with the
present invention as shown in FIG. 1.
[0023] The drawings referred to in this specification should be
understood as not being drawn to scale except if specifically
noted.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] Reference is made now in detail to a specific embodiment of
the present invention, which illustrates the best mode presently
contemplated by the inventors for practicing the invention.
Alternative embodiments are also briefly described as
applicable.
[0025] FIG. 1 depicts an ink-jet hard copy apparatus, in this
exemplary embodiment, a computer peripheral, color printer, 101. A
housing 103 encloses the electrical and mechanical operating
mechanisms of the printer 101. Operation is administrated by an
internal electronic controller (usually a microprocessor or
application specific integrated circuit ("ASIC") controlled printed
circuit board) connected by appropriate cabling (not shown) to the
computer. It is well known to program and execute imaging,
printing, print media handling, control functions, and logic with
firmware or software instructions for conventional or general
purpose microprocessors or ASIC's. Cut-sheet print media
105--referred to generically hereinafter simply as "paper,"
regardless of actual medium selected by the end-user--is loaded by
the end-user onto an input tray 120. Sheets of paper are then
sequentially fed by a suitable, internal, paper-path transport
mechanism (not shown) to an internal printing station platen, or
"print zone," 107 where graphical images or alphanumeric text are
created using state of the art color imaging and text rendering
using dot matrix manipulation techniques. A carriage 109, mounted
on a slider 111, scans the paper sheet delivered to the print zone
107. An encoder strip 113 and appurtenant position encoding devices
on the carriage 109 and as part of the controller are provided for
keeping track of the position of the carriage 109 at any given time
(see e.g., a SINGLE CHANNEL ENCODER SYSTEM and a SINGLE CHANNEL
ENCODER WITH SPECIFIC SCALE SUPPORT STRUCTURE are described by
Majette et al. in U.S. Pat. Nos. 4,789,874 and 4,786,803,
respectively (assigned to the common assignee of the present
invention and incorporated herein by reference). A set of
individual ink-jet writing instruments, "pens," 115K, 115C, 115M,
115Y, 115F, each having ink-jet printheads as would be known in the
art (not seen in this perspective), are releasably mounted in fixed
positions on the carriage 109 for easy access and repair or
replacement. Each printhead mechanisms is adapted for "jetting"
minute droplets of ink or other fluids (see e.g., Allen, supra) to
form dots on adjacently positioned paper in the print zone 107.
Refillable or replaceable ink supply cartridges, or "reservoirs,"
117K, 117C, 117M, 117Y are provided; generally, in a full color
ink-jet system, inks for the subtractive primary colors, cyan,
yellow, magenta (CYM) and a true black (K) ink are used; note
however that additive primary colors--red, blue, green--or other
colorants can be used). In this set, a pen 115F and cartridge 117F
for a clear fluid fixer "F," is also provided. The pens 115 are
coupled to respective cartridges by flexible tubing 119. Note also
that the present invention can be implemented in hard copy
apparatus employing self-contained supply, replaceable, ink-jet
cartridges as are known in the art. Once a printed page is
completed, the sheet of paper is ejected onto an output tray 121.
It is common in the art to refer to the pen scanning direction as
the x-axis, the paper feed direction as the y-axis, and the ink
drop firing direction as the z-axis.
[0026] FIG. 2 is a schematic depiction of an optical sensor unit
used in accordance with the present invention. Ink-jet nozzles of
the printheads are generally in-line with the sensor module 201 in
the x-axis by mounting the module 201 appropriately on the carriage
109 (FIG. 1). The sensor module 201 optically senses visible pen
markings on the paper--namely ink dots or sets of ink dots--and
provides electrical signals to the controller and the alignment
algorithm, indicative of the registration of the portions of the
printed pattern produced. An optical component holder 203 contains
a lens 205. In the exemplary embodiment shown, one or more
light-emitting diodes ("LEDs") 207 are mounted at an angle to the
plane of the print zone 107 (FIG. 1). As will be recognized by a
person skilled in the art, it is also known in the art to use
refraction and diffusion devices to align the light emitting and
light sensitive components.
[0027] The LEDs 207 project light onto a test pattern "TP" printed
with the printheads on the paper 209, and the light is then
reflected to a photodetector 211. Known manner optical sensing and
signal process techniques are applied wherein the actual sensed
pattern can be compared to the test pattern expected (see e.g.,
Cobbs et al., supra). For further details regarding a specific,
multifunction, optical sensor module useful in accordance with the
present invention, reference can be made to U.S. patent application
Ser. No. 09/183,086 (filed Oct. 28, 1998 by WALKER et al. (assigned
to the common assignee of the present invention and incorporated
herein by reference).
[0028] FIG. 3 is a schematic representation of an exemplary
embodiment test pattern in accordance with the present invention
used for alignment of the clear fluid printhead to the other ink
pen 115 printheads. An actual test pattern would be in color and is
represented by the labeled shadings in this black and white
exemplary rendition.
[0029] A predetermined pattern 301 of bars 305, or other geometric
shapes suitable to the particular implementation, is laid down on
the paper using only clear fixer. The bars 305 in the known test
pattern 301 are in effect a series of positional-calibration
indicia; that is, from the data base comprising the pattern and the
position of the carriage 109 as determined by the encoder 113, the
bars printed from the pattern data relate the printhead position of
the clear fixer pen 115F at the time of firing toward a specific
target picture element ("pixel") on the paper. The particular
pattern implemented for a specific embodiment or purpose only need
consist of a fractional fill pattern created on the blank
paper.
[0030] Then, the clear fixer test pattern of bars 305 and regions
303 between the bars are overlaid with ink from one or more of the
pens. The next swath height (equal to printhead height) of pattern
of fixer bars 305 is printed. The process continues for all inks or
combinations of ink that are of interest. It should be noted that
there may be particular chemistry embodiments where fixer is
deposited after the colorant.
[0031] The result is a test pattern wherein the color inks will
diffuse into the paper in regions 303 where there is no fixer,
namely, between the geometric bars 305. This results in less vivid
color regions 303 between the fixer bars 305. It has been found
that the reflectivity of overlaid fixer bars 305 is a recognizable
difference from the diffuse regions 303 where no fixer was laid
down before overprinting with a colorant.
[0032] Other colors can be made by mixing inks during a scan.
Depending on the wavelength of the LED 207, particular colors to
which the LED will be more sensitive can be used.
[0033] The generated data--namely, the actual position of the bars
305 of pixels having fixer thereon derived from the encoder 113
data and sensor 201 data--is compared to the expected position
based on the given test pattern data. The alignment algorithm
determines particular nozzle firing misalignments and the results
are used by the printer's printing algorithm for operation printing
jobs. Corrections for deviations in the carriage-scan x-axis and
the paper scan y-axis can be calculated. For example, the Cobbs et
al., supra, algorithm works for offsets between pens, along the
paper advance y-axis can be corrected by selecting certain
printhead nozzles for activation. Another correction could be
applied by masking the data as being between swaths of the marking
implements as taught by Sievert et al., supra.
[0034] The present invention provides a test pattern where enhance
contrast of regions having fixer are overlaid with sensor visible
ink because the aggregations of fixer and colorant are broken up
rather than being continuous across an entire test image.
[0035] The foregoing description of the preferred embodiment of the
present invention has been presented for purposes of illustration
and description. It is not intended to be exhaustive or to limit
the invention to the precise form or to exemplary embodiments
disclosed. Obviously, many modifications and variations will be
apparent to practitioners skilled in this art. Similarly, any
process steps described might be interchangeable with other steps
in order to achieve the same result. The embodiment was chosen and
described in order to best explain the principles of the invention
and its best mode practical application, thereby to enable others
skilled in the art to understand the invention for various
embodiments and with various modifications as are suited to the
particular use or implementation contemplated. It is intended that
the scope of the invention be defined by the claims appended hereto
and their equivalents.
* * * * *