U.S. patent application number 11/269041 was filed with the patent office on 2007-05-10 for methods and systems for identifying ink.
Invention is credited to Gary W. Larson, Lufei Lin, Zeying Ma.
Application Number | 20070102635 11/269041 |
Document ID | / |
Family ID | 38002825 |
Filed Date | 2007-05-10 |
United States Patent
Application |
20070102635 |
Kind Code |
A1 |
Ma; Zeying ; et al. |
May 10, 2007 |
Methods and systems for identifying ink
Abstract
The present invention relates to methods for tagging an ink with
a detectable marker and methods for identifying an ink. The tagged
ink includes a colorant visible under visible light and a
detectable marker capable of fluorescing when subjected to infrared
light. A method for identifying an ink includes obtaining a sample
of an unidentified ink, subjecting the sample to infrared light
such that a detectable marker, if present, fluoresces, and
determining whether any fluorescence emitted from the sample
corresponds to fluorescence from a tagged ink. A system for
identifying an unidentified ink is also disclosed.
Inventors: |
Ma; Zeying; (San Diego,
CA) ; Larson; Gary W.; (San Diego, CA) ; Lin;
Lufei; (San Diego, CA) |
Correspondence
Address: |
HEWLETT PACKARD COMPANY
P O BOX 272400, 3404 E. HARMONY ROAD
INTELLECTUAL PROPERTY ADMINISTRATION
FORT COLLINS
CO
80527-2400
US
|
Family ID: |
38002825 |
Appl. No.: |
11/269041 |
Filed: |
November 8, 2005 |
Current U.S.
Class: |
250/338.1 |
Current CPC
Class: |
C09D 11/30 20130101;
G01N 21/6428 20130101; G01N 33/32 20130101; C09D 11/03 20130101;
G01N 2021/6439 20130101; B41M 3/144 20130101 |
Class at
Publication: |
250/338.1 |
International
Class: |
G01J 5/00 20060101
G01J005/00 |
Claims
1. A method for identifying an ink, the method comprising:
obtaining a sample of an unidentified ink; subjecting the sample of
the unidentified ink to infrared light capable of causing a
detectable marker, if present, in the sample of the unidentified
ink to fluoresce; and determining whether fluorescence emitted from
the sample of the unidentified ink, if any, corresponds to
fluorescence of an authentic ink known to include the detectable
marker.
2. The method according to claim 1, further comprising subjecting
the sample of the unidentified ink to a separation procedure
capable of separating the detectable marker, if present, from a
component of the unidentified ink.
3. The method according to claim 2, wherein subjecting the sample
of the unidentified ink to the separation procedure comprises:
mixing the ink sample with a solvent; and subjecting the ink sample
and the solvent to chromatography.
4. The method according to claim 1, wherein the authentic ink
comprises a colorant.
5. The method according to claim 1, wherein the authentic ink
comprises between about 10 ppm and about 10000 ppm of the
detectable marker.
6. The method according to claim 1, wherein the detectable marker
comprises an infrared fluorescing agent.
7. The method according to claim 1, wherein the detectable marker
comprises TINOLUX BBS.
8. A method for tagging an ink, the method comprising: providing an
ink comprising a colorant visible under visible light; and mixing
the ink with a detectable marker capable of fluorescing when
subjected to infrared light, such that the detectable marker is
present in the ink at a concentration of between about 10 ppm and
about 10000 ppm.
9. The method according to claim 8, wherein the detectable marker
comprises a metal phthalocyanine.
10. The method according to claim 8, wherein the detectable marker
comprises TINOLUX BBS.
11. The method according to claim 8, wherein the detectable marker
is present in the ink at a concentration of between about 50 ppm
and about 100 ppm.
12. The method according to claim 8, wherein the colorant is a dye
or a pigment.
13. The method according to claim 1, further comprising mixing the
ink with at least one isotope of an element.
14. A method for deterring the incidence of ink counterfeiting, the
method comprising: adding a detectable marker capable of
fluorescing when subjected to infrared light to an ink, thus
producing an authentic ink; obtaining an ink sample; exposing at
least part of the ink sample to infrared light; and determining
whether the ink sample includes the detectable marker.
15. The method according to claim 14, further comprising subjecting
the ink sample to a separation procedure capable of separating the
detectable marker, if present, from a component of the ink
sample.
16. The method. according to claim 15, wherein subjecting the ink
sample to the separation procedure comprises: mixing the ink sample
with a solvent; and subjecting the ink sample and the solvent to
chromatography.
17. The method according to claim 16, wherein the chromatography
comprises thin layer chromatography.
18. The method according to claim 14, wherein the detectable marker
comprises an infrared fluorescing agent.
19. The method according to claim 14, wherein a concentration of
the detectable marker in the authentic ink is between about 10 ppm
and about 10000 ppm.
20. The method according to claim 19, wherein the concentration of
the detectable marker in the authentic ink is between about 50 ppm
and about 100 ppm.
21. The method according to claim 14, wherein the detectable marker
comprises TINOLUX BBS.
22. The method according to claim 14, wherein determining whether
the ink sample includes the detectable marker comprises comparing
fluorescence of the ink sample to fluorescence of the authentic
ink.
23. The method according to claim 14, wherein the ink comprises a
visible colorant.
24. The method according to claim 14, further comprising adding at
least one isotope of an element the ink, thus producing the
authentic ink.
25. An ink composition, comprising: a colorant visible under
visible light; and a means for fluorescing when subjected to
infrared light; wherein the means for fluorescing is present in the
ink composition at a concentration of between about 10 ppm and
about 10000 ppm.
26. The ink composition of claim 25, wherein the infrared
fluorescing agent comprises a metal phthalocyanine.
27. The ink composition of claim 26, wherein the infrared
fluorescing agent comprises TINOLUX BBS.
28. The ink composition of claim 25, wherein the means for
fluorescing is present at a concentration of between about 50 ppm
and about 100 ppm.
29. The ink composition of claim 25, wherein the colorant is a dye
or a pigment.
30. The ink composition of claim 25, further comprising at least
one isotope of an element.
31. A system for identifying an unidentified ink, comprising: a
separation means for separating a detectable marker, if present,
from a component of the unidentified ink; a light source for
producing infrared light; and an infrared viewer for detecting
fluorescence generated by the detectable marker, if present, when
subjected to the infrared light.
32. The system of claim 31, wherein the separation means comprises
a solvent and a thin layer chromatography plate.
33. The system of claim 31, wherein the infrared viewer comprises a
single chip black and white camera.
34. The system of claim 31, wherein the system is configured to be
portable.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is related to a patent application
entitled, "Methods for Tagging and Authenticating Inks Using
Compositions" (Attorney Docket No. 200309791-2), filed on even date
with this application.
FIELD OF THE INVENTION
[0002] The present invention relates to methods for identifying
inks. More particularly, the present invention relates to methods
for tagging or adding a detectable marker to an ink. Further, the
present invention relates to methods for authenticating ink samples
by probing the ink for the presence of the detectable marker in an
ink sample.
BACKGROUND OF THE INVENTION
[0003] Inkjet printers operate by placing small droplets of ink
onto a medium, (e.g., a sheet of paper) to create an image. Inks
used in inkjet printers are typically stored in and dispensed from
one or more inkjet cartridges that are specific for the inkjet
printer with which they are used. Once the ink in the inkjet
cartridge has been used, the cartridge must be replaced or
refilled. Refilling of inkjet cartridges is a relatively simple
task and refill kits are readily available.
[0004] The ease with which inkjet cartridges may be refilled lends
itself to a high susceptibility for counterfeiting. This can lead,
for instance, to damage to the reputation of an ink manufacturer if
in an inkjet cartridge is replaced with a counterfeit ink of
inferior quality and sold with the manufacturer's label attached to
the cartridge. Additionally, counterfeiting may lead to large
expenditures of warranty monies paid out by an ink manufacturer if,
for example, an authentic ink of the ink manufacturer is replaced
with a counterfeit ink, or diluted, and then returned to the
manufacturer accompanied by a complaint of substandard ink
quality.
[0005] Techniques have been developed for tagging various articles
to prevent counterfeiting or at least reduce the incidence thereof.
For instance, the various articles may be tagged with code-bearing
micro-particles, bulk chemical substances, or radioactive
substances. However, tagging techniques that are applicable to
other articles or materials are not necessarily suitable for
tagging inks. Inks are typically formulated to provide maximum
performance in terms of, among other traits, color, physical and
chemical properties, and interaction of the ink with the medium on
which they are printed.
[0006] Some identification techniques for tagging and tracing
materials such as inks, paintings, explosives, pollutants, and
other articles exist. These techniques may employ inorganic salts,
ultraviolet (UV) absorbers, nucleic acids or metals as a tag,
wherein the tag is used to identify or authenticate the tagged
material. Analytical tools. used to detect these tags or traces
include paper chromatography, UV-visible spectrophotometers, X-ray
microanalysis or electrophoresis.
[0007] Although these techniques may enable the detection or
quantification of the tagged material, the incorporation of the tag
into the ink may hinder ink development by the ink manufacturer.
For instance, ensuring printer performance is an expensive and
time-consuming process for the ink manufacturer and the prevention
of counterfeiting inks further frustrates the goal of ensuring
printer performance.
[0008] While some metal and other multi-valent salts may have
utility in tagging certain articles, they are not suitable for
tagging inks used in thermal ink-jet printers because trace amounts
of unwanted cations such as Fe3+, Cr3+ and Si4+ may cause
mis-directed ink drops or misfiring of the ink jet nozzles.
Further, the use of UV absorbent materials or other fluorescent
brighteners may add unwanted effects to color appearances of the
ink or may fade upon prolonged exposure to light.
BRIEF SUMMARY OF THE INVENTION
[0009] In one embodiment, a method for identifying an ink comprises
obtaining a sample of the unidentified ink and subjecting the
sample of the unidentified ink to infrared light capable of causing
a detectable marker, if present, in the sample of the unidentified
ink to fluoresce. The method further includes determining whether
fluorescence emitted from the sample of the unidentified ink, if
any, corresponds to fluorescence of an authentic ink known to
include the detectable marker.
[0010] In an additional embodiment, a method for tagging an ink
includes providing an ink comprising a colorant visible under
visible light. The method further includes mixing the ink with a
detectable marker capable of fluorescing when subjected to infrared
light, such that the detectable marker is present in the ink at a
concentration of between about 10 ppm and about 10000 ppm.
[0011] In another embodiment, a method for deterring the incidence
of ink counterfeiting is described. The method includes adding a
detectable marker capable of fluorescing when subjected to infrared
light or a tagging composition having at least one isotope of an
element to an ink, thus producing an authentic ink. The method
further includes obtaining an ink sample, exposing at least part of
the ink sample to infrared light or determining whether the
unidentified ink includes an abundance of at least one isotope, and
determining whether the ink sample includes the detectable
marker.
[0012] An ink composition is disclosed in yet another embodiment.
The ink composition includes a colorant visible under visible light
and means for fluorescing the same when subjected to infrared
light, wherein the means for fluorescing is present in the ink
composition at a concentration of between about 10 ppm and about
10000 ppm.
[0013] In yet a further embodiment, a system for identifying an
unidentified ink includes a separation means for separating a
detectable marker, if present, from a component of the unidentified
ink. The system also includes a light source for producing infrared
light and an infrared viewer for detecting fluorescence generated
by the detectable marker, if present, when subjected to the
infrared light.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] While the specification concludes with claims particularly
pointing out and distinctly claiming that which is regarded as the
present invention, the advantages of this invention may be more
readily ascertained from the following description of the invention
when read in conjunction with the accompanying drawings in
which:
[0015] FIG. 1 is chart which illustrates the .sup.6Li isotope
count, .sup.7Li isotope count, and .sup.6Li .sup.7Li isotope ratio
of a number of authentic ink samples tagged with one embodiment of
a detectable marker including 10 ppb .sup.6Li isotope and a
corresponding number of ink samples which have been adulterated by
20% so that they contain 8 ppb .sup.6Li;
[0016] FIG. 2 is chart which illustrates the .sup.6Li isotope
count, .sup.7Li isotope count, and .sup.6Li/.sup.7Li isotope ratio
of a number of authentic ink samples tagged with one embodiment of
a detectable marker 10 ppb .sup.6Li isotope and a corresponding
number of ink samples which, in one embodiment, have been
adulterated by 50% so that they contain 5 ppb .sup.6Li;
[0017] FIG. 3 is chart which illustrates the .sup.6Li isotope
count, .sup.7Li isotope count, and .sup.6Li/.sup.7Li isotope ratio
of a number of authentic ink samples tagged with one embodiment of
a detectable marker 10 ppb .sup.6Li isotope and a corresponding
number of ink samples which, in one embodiment, have been
adulterated by 80% so that they contain 2 ppb .sup.6Li;
[0018] FIG. 4 is chart which illustrates the .sup.6Li isotope
count, .sup.7Li isotope count, and .sup.6Li/.sup.7Li isotope ratio
of a number of authentic ink samples tagged with one embodiment of
a detectable marker 10 ppb .sup.6Li isotope and a corresponding
number of ink samples which, in one embodiment, have been diluted
by 50% so that they contain 5 ppb .sup.6Li;
[0019] FIG. 5 is chart which illustrates the .sup.6Li isotope
count, .sup.7Li isotope count, and .sup.6Li/.sup.7Li isotope ratio
of a number of authentic ink samples tagged with one embodiment of
a detectable marker 10 ppb .sup.6Li isotope and a corresponding
number of ink samples which, in one embodiment, have been diluted
by 80% so that they contain 2 ppb .sup.6Li;
[0020] FIG. 6 is a molecular diagram of one embodiment of an
infrared marker of the present invention;
[0021] FIG. 7 illustrates the results of one embodiment of a method
of separating ink from the infrared marker of the present invention
when viewed under visible light;
[0022] FIG. 8 illustrates the results of the method of separating
ink from the infrared marker as shown in FIG. 7 under infrared
light; and
[0023] FIGS. 9A and 9B illustrate results of another embodiment of
a method of separating ink components from the infrared marker of
the present invention viewed under visible light (FIG. 9A) and
infrared lights (FIG. 9B).
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention is directed to methods for tagging
inks with a detectable marker and methods for authenticating inks
or detecting counterfeit inks. In one embodiment, the detectable
marker includes at least one isotope of an element and, in another
embodiment, the detectable marker comprises an infrared fluorescing
agent. In other embodiments, methods for reducing the incidence of
ink counterfeiting and systems for identifying an unidentified ink
are described.
[0025] In one embodiment, tagging compositions are used for tagging
or labeling an ink for identification and authentication. As used
herein, the term "tagging composition" or "labeling composition"
refers to a composition having a detectable marker. That is, the
inks of the present invention are tagged or labeled with a
detectable marker such that the ink comprises a detectable marker
that may be used to identify or authenticate the ink. As used
herein, "detectably different" abundances means that the difference
between the abundance of the tagging composition prior to
incorporation of the detectable marker and a respective abundance
after incorporation of the detectable marker is larger than the
experimental error of the detection method utilized (e.g.,
inductively coupled plasma mass spectrometry (ICP-MS) in the case
of isotopes). The tagging compositions which may be used in the
methods of the present invention may be non-toxic and inert at the
desired concentration levels and are capable of incorporation into
an ink without altering the attractiveness or performance
thereof.
[0026] The tagging compositions of the present invention may also
include a suitable carrier. The carriers are materials in which one
or more detectable markers may be dispersed or dissolved. The
carrier may be any material which is inert at the concentration
level used (i.e., a material which has no reaction or limited
reaction with the ink components) to facilitate the tagging
compositions being incorporated into the inks to be tagged. The
carrier may be a liquid in which one or more detectable markers may
be dissolved to produce a substantially homogenous solution.
Suitable liquids include, but are not limited to, solvents, water,
and alcohols.
[0027] The tagging compositions of the present invention may be
incorporated into an ink to produce a tagged ink having at least
one detectable marker present in a detectable amount. As used
herein, the term "authentic ink" refers to an ink which includes a
detectable marker and which, accordingly, may comprise an
artificial abundance of an isotope of an element which exceeds a
natural amount of the isotope in the ink or an infrared fluorescing
agent detectable with infrared light. By incorporating the
detectable marker into an ink in this manner to produce an
authentic ink, the quality and integrity of the ink may be
preserved and yet the concentration of the detectable marker in the
ink may be detected by suitable detection technology.
[0028] The tagged inks having the detectible marker are distributed
in commerce such that the tagged inks may be purchased by consumers
or retailers. In this manner, the ink vendor or manufacturer may
test or authenticate their inks to reduce the incidence of ink
counterfeiting or deter counterfeiters from producing counterfeit
inks.
[0029] In one embodiment, the detection technology may comprise
inductively coupled plasma mass spectrometry (ICP-MS), which is
capable of detecting an isotope concentration for a number of
different isotopes in the parts per billion (ppb) range in a
relatively short period of time, (e.g., less than 10 minutes). In
another embodiment, the detection technology may comprise a source
of infrared light which may be used in combination with a
separation means for separating the ink from the detectable
marker.
[0030] In one embodiment, a method for tagging an ink for
identification comprises incorporating a detectable marker into an
ink. In one embodiment, the detectable marker may include an
isotope that may be prepared or isolated for use in the tagging
compositions using conventional isotope extraction methods,
including plasma separation processes, electromagnetic separation,
molecular laser isotope separation, atomic vapor laser isotope
separation, gas centrifugation, gas diffusion, and distillation.
Each of these methods is conventional and, accordingly, isotope
extraction is not further discussed herein. Additionally, highly
enriched samples of most stable isotopes are commercially available
from a number of sources including, but not limited to, Inorganic
Ventures/IV Labs of Lakewood, N.J.
[0031] In one embodiment, a method for tagging an ink for
identification comprises tagging the ink with a detectable marker,
such as, for example, a tagging composition comprising an augmented
abundance of at least one isotope of an element or an infrared
fluorescing agent to produce an authentic ink having an artificial
abundance of at least one isotope of an element or the infrared
fluorescing agent, which exceeds a natural abundance thereof in the
authentic ink. At least one isotope may be present in the authentic
ink in a concentration of from about 1 to about 1000 parts per
billion.
[0032] In one embodiment, the tagging composition may comprise an
augmented abundance of at least one isotope of a first element and
at least one isotope of a second element. The first and second
elements may be different from one another. An authentic ink
including the tagging composition has an artificial abundance of at
least one isotope of the first element and an artificial abundance
of at least one isotope of the second element, each of which
exceeds the respective natural abundances thereof in the authentic
ink.
[0033] In another embodiment, the tagging composition may comprise
an augmented abundance of at least two isotopes of a single
element, wherein the artificial abundance of each of at least two
isotopes exceeds a respective natural abundance thereof in the
authentic ink. The tagging composition may have a ratio of the
artificial abundance of a first of the at least two isotopes
relative to the artificial abundance of a second of the at least
two isotopes that is different from a natural abundance ratio for
the isotopes in the authentic ink.
[0034] In a further embodiment, a method for authenticating an
unidentified ink includes tagging an ink with a tagging composition
having an augmented abundance of at least one isotope of an element
or an infrared fluorescing agent to produce an authentic ink. The
authentic ink may have an artificial abundance of at least one
isotope or the infrared fluorescing agent which exceeds a natural
abundance thereof in the authentic ink. A sample of the
unidentified ink is obtained and an abundance of at least one
isotope in the unidentified ink sample is detected using
inductively coupled plasma mass spectrometry, or the infrared
fluorescing agent is detected using an infrared light source to
determine whether the unidentified ink is the authentic ink based
upon a comparison of the detected abundance of at least one isotope
in the unidentified ink sample and the artificial abundance of at
least one isotope in the authentic ink sample, or based on the
presence or the absence of the infrared fluorescing agent.
[0035] In one embodiment, if a ratio of the detected abundance of
at least one isotope in the unidentified ink sample relative to the
artificial abundance of at least one isotope in the authentic ink
is less than 0.66, the unidentified ink may be designated as
counterfeit. At least one isotope may be present in the composition
in a concentration of between about 1 and about 1000 parts per
billion and may be selected from isotopes of lithium, rubidium,
cesium, certain alkaline metals (e.g., beryllium, magnesium,
strontium, and barium), certain transition metals (e.g., manganese,
cobalt, nickel, copper, zinc, yttrium, niobium, rhodium, and
rhenium), certain rare earth elements (e.g., lanthanum, cerium,
praseodymium, europium, gadolinium, terbium, and lutetium), and
combinations of any thereof.
[0036] In yet another embodiment, a method for authenticating an
ink includes obtaining a sample of an unidentified ink and
detecting an abundance of at least one isotope of an element in the
unidentified ink sample using inductively coupled plasma mass
spectrometry or detecting the infrared fluorescing agent using an
infrared light source. The detected abundance is compared to a
tagging record which correlates an authentic ink identifier with
information regarding an authentic ink. The authenticity of the
unidentified ink is determined based upon a comparison of the
detected abundance of at least one isotope or the presence of the
infrared fluorescing agent in the unidentified ink sample and the
tagging record. The authentic ink may comprise an artificial
abundance of at least one isotope which exceeds a natural abundance
of at least one isotope in the authentic ink or the infrared
fluorescing agent. Additionally, at least one isotope may be
present in the authentic ink in a concentration of between about 1
and about 1000 parts per billion and may be selected from isotopes
of lithium, rubidium, cesium, certain alkaline metals (e.g.,
beryllium, magnesium, strontium, and barium), certain transition
metals (e.g., manganese, cobalt, nickel, copper, zinc, yttrium,
niobium, rhodium, and rhenium), certain rare earth elements (e.g.,
lanthanum, cerium, praseodymium, europium, gadolinium, terbium, and
lutetium), and combinations of any thereof.
[0037] Any element having at least one stable isotope may be used
in the tagging compositions of the present invention. In one
embodiment, light elements are employed such as, for example,
elements of the alkali group that tend to have limited interaction
with the other components which typically are included in inkjet
inks, as well as having limited interaction with the inkjet
cartridge components.
[0038] By way of example, and not limitation, elements which may be
used in one embodiment of the tagging compositions of the present
invention include, but are not limited to lithium (Li), rubidium
(Rb), cesium (Cs), certain alkaline metals (e.g., beryllium (Be),
magnesium (Mg), strontium (Sr), and barium (Ba)), certain
transition metals (e.g., manganese (Mn), cobalt(Co), nickel (Ni),
copper (Cu), zinc (Zn), yttrium (Y), niobium (Nb), rhodium (Rh),
and rhenium (Re)), and certain rare earth elements (e.g., lanthanum
(La), cerium (Ce), praseodymium (Pr), europium (Eu), gadolinium
(Gd), terbium (Tb), lutetium (Lu)), and any combinations
thereof.
[0039] Each of the above listed exemplary elements has at least one
stable isotope. In this regard, isotopes of the exemplary elements
which are used in the tagging compositions of the present invention
include, by way of example only and not limitation, .sup.6Li,
.sup.7Li, .sup.85Rb, .sup.87Rb, .sup.133Cs, .sup.9Be, .sup.24Mg,
.sup.25Mg, .sup.26Mg, .sup.84Sr, .sup.86Sr, .sup.87Sr, .sup.88Sr,
.sup.130Ba, .sup.132Ba, .sup.134Ba, .sup.135Ba, .sup.136Ba,
.sup.137Ba, .sup.138Ba, .sup.55Mn, .sup.59Co, .sup.58Ni, .sup.60Ni,
.sup.62Ni, .sup.63Cu, .sup.65Cu, .sup.64Zn, .sup.66Zn, .sup.68Zn,
.sup.89Y, .sup.93Nb, .sup.103Rh, .sup.185Re, .sup.187Re,
.sup.139La, .sup.140Ce, .sup.141Pr, .sup.151Eu, .sup.153Eu,
.sup.152Gd, .sup.154Gd, .sup.155Gd, .sup.157Gd, .sup.160Gd,
.sup.159Tb, .sup.175Lu, and any combinations thereof.
[0040] In one embodiment, the .sup.6Li isotope is used as it is
unique and highly sensitive to detection via ICP-MS in the shield
plate cool plasma condition, i.e., it can be detected in a
concentration as low as between about. 1 and about 100 ppb. The
element lithium (Li) has two stable isotopes with atomic masses of
6 and 7. In natural lithium, these two isotopes are present in the
concentration of 7.50% and 92.50%, respectively. Accordingly, when
an ink is tagged with the .sup.6Li isotope, the abundance of the
.sup.7Li isotope is altered as well.
[0041] Combinations of isotopes and elements may be incorporated
into the tagging compositions of the present invention to create
authentic inks that are difficult for would-be counterfeiters to
replicate.
[0042] In another embodiment, a method of the present invention
includes incorporating a detectable marker into an ink. In one
embodiment, the detectable marker may include an infrared
fluorescing agent that may be detected under infrared (IR) light
such as, for example, TINOLUX BBS.
[0043] In another embodiment, the present invention describes a
method for authenticating an unidentified ink. When the detectable
marker comprises at least one isotope, the method may comprise
comparing information extracted from a sample of the unidentified
ink with information that is known about an authentic ink and the
one or more tagging compositions with which the authentic ink has
been tagged, to determine whether the unidentified ink sample is a
sample of the authentic ink or is a sample of a counterfeit
ink.
[0044] In one embodiment, the method includes obtaining a sample of
an unidentified ink and detecting an abundance in the unidentified
ink sample of at least one isotope with which the authentic ink has
been tagged using ICP-MS. The detected abundance of at least one
isotope in the unidentified ink sample may subsequently be compared
with the known artificial abundance of at least one isotope in the
authentic ink to determine whether the unidentified ink sample is
the authentic ink.
[0045] As the natural abundance of a given isotope in an ink is not
constant, a simple comparison of the raw abundance numbers (i.e.,
isotope mass counts) may not provide an accurate indication of
whether or not the two inks being compared are the same ink.
Accordingly, in one embodiment, a ratio of the detected abundance
of at least one isotope in the unidentified ink sample to the
artificial abundance of at least one isotope in the authentic ink
may be determined. If this ratio is less than about 0.66, the
unidentified ink sample may be designated as counterfeit. However,
if this ratio is greater than or equal to 0.66, it is likely that
the unidentified ink sample is a sample of the authentic ink.
[0046] In one embodiment, an ink may be tagged with a tagging
composition comprising an augmented abundance of at least one
isotope of a first element and an augmented abundance of at least
one isotope of a second element, the first and second elements
being different from one another, to produce the authentic ink. If
a tagging composition in accordance with this embodiment is
utilized to produce the authentic ink, an abundance of each of two
isotopes may be detected in the unidentified ink sample and that
information regarding the artificial abundances of the two isotopes
be known with respect to the authentic ink. Using this information,
a ratio of the detected abundance of the isotope of a first element
in the unidentified ink sample to the artificial abundance of the
isotope of the first element in the authentic ink may be
determined, as may a ratio of the detected abundance of the isotope
of a second element in the unidentified ink sample to the
artificial abundance of the isotope of the second element in the
authentic ink. If either or both of these ratios are less than
0.66, the unidentified ink sample may be designated as
counterfeit.
[0047] An unidentified isotope ratio may be determined for the
unidentified ink sample. The unidentified isotope ratio is a ratio
of the detected abundance of at least one isotope of the first
element to the detected abundance of at least one isotope of the
second element in the unidentified ink sample. Similarly, an
authentic isotope ratio, i.e., the ratio of the artificial
abundance of at least one isotope of the first element to the
artificial abundance of at least one isotope of the second element
in the authentic ink sample, may be determined. If the ratio of the
unidentified isotope ratio to the authentic isotope ratio is less
than 0.66, the unidentified ink sample may be designated as
counterfeit.
[0048] Further, in another embodiment, an ink may be tagged with a
tagging composition comprising an augmented abundance of at least
two isotopes of a single element to produce an authentic ink. If a
tagging composition in accordance with this embodiment is utilized
to produce the authentic ink, an abundance of each of at least two
isotopes of the element may be detected in the unidentified ink
sample and that information regarding the artificial abundance of
each of at least two isotopes of the element be known with respect
to the authentic ink. An unidentified isotope ratio, (i.e., the
ratio of the detected abundance of a first of the at least two
isotopes of the element to the detected abundance of a second of at
least two isotopes of the element) may be determined for the
unidentified ink sample and that an authentic isotope ratio (i.e.,
the ratio of the artificial abundance of a first of at least two
isotopes of the element to the artificial abundance of a second of
the at least two isotopes of the element) be determined for the
authentic ink.
[0049] Using this information, a ratio of the detected abundance of
a first of at least two isotopes of the element in the unidentified
ink sample to the artificial abundance of the first of at least two
isotopes of the element in the authentic ink may be determined, as
may a ratio of the detected abundance of the second of at least two
isotopes of the element in the unidentified ink sample to the
artificial abundance of the second of at least two isotopes of the
element in the authentic ink. If either or both of these ratios are
less than 0.66, the unidentified ink sample may be designated as
counterfeit. Further, if the ratio of the unidentified isotope
ratio to the authentic isotope ratio is less than 0.66, the
unidentified ink sample may also be designated as counterfeit.
[0050] To facilitate a comparison between information extracted
from an unidentified ink sample and information known about an
authentic ink, information regarding the authentic ink may be
recorded in a tagging record for use in determining authenticity
and detecting counterfeit inks. The term "tagging record," as used
herein, refers to information (record) which correlates an
identifier for the authentic ink with information regarding the
detectable marker with which the ink has been tagged. For instance,
an authentic ink identifier may comprise one or more pieces of
information about the ink including, but not limited to, a serial
number, a batch number, a lot number the date of manufacture, and
the name brand of the ink. The authentic ink identifier may be
correlated in the tagging record with information regarding the
isotope(s), the infrared fluorescing agent, or a combination
thereof with which the ink has been tagged, including, but not
limited to, the element used for tagging, the isotope of the
element that was used (if there is more than one stable isotope),
the concentration at which the isotope is present in the ink, the
type of infrared fluorescing agent in the ink, the wavelength of
light at which the infrared fluorescing agent fluoresces in the
ink, and which inks in a cartridge the detectable marker is placed.
Tagging records may be made at the time an authentic ink is
tagged.
[0051] In an additional embodiment, a tagging record may include
information about which inks or dyes in an ink set include an
isotope(s) and an infrared fluorescing agent. In this manner, a
presumptive, qualitative test may be performed on an ink sample in
the field to determine whether the infrared fluorescing agent is
present in the ink. If the qualitative test indicates that the
infrared fluorescing agent is present in the ink, a quantitative
test may be performed to quantitate the amount of isotope(s)
present in the ink and further characterize the ink sample to
determine if the ink sample is authentic.
[0052] In another embodiment, the detectable marker may include an
infrared fluorescing agent that is detectable with infrared light.
A method for authenticating an unidentified ink includes subjecting
the unidentified ink to a process capable of separating the
detectable marker from the ink components of the unidentified ink,
and subjecting the separated ink components to a source of infrared
illumination such that, if present, the separated detectable marker
will be illuminated with the infrared light.
[0053] In a further embodiment, a system for identifying an
unidentified ink includes a separation means for separating a
detectable marker, if present, from components of an ink. The
system also includes a light source for producing infrared light
and an infrared viewer for detecting any fluorescence generated by
the detectable marker if present in the unidentified ink. The
separation means may comprises a solvent and use of a chromatograph
as described herein. The infrared viewer may be a single chip black
and white camera. In another embodiment, the system is configured
to be portable such that the system may be utilized in the field
such as, for example, at a retail store.
[0054] The following examples describe various embodiments of
methods and systems for authenticating an ink in accordance with
the present invention. The examples are merely illustrative and are
not meant to limit the scope of the present invention in any
way.
EXAMPLE 1
Preparation of an Authentic Ink
[0055] An isotope solution enriched with the .sup.6Li isotope was
obtained from Inorganic Ventures/IV Labs of Lakewood, N.J. The
.sup.6Li isotope enriched solution contained about 1002.+-.1 ppm
.sup.6Li and 67.+-.1 ppm .sup.7Li in 5.0% HNO.sub.3. Thus, it can
be seen that the .sup.6Li isotope enriched solution contained about
6.7% .sup.7Li isotope as well. A 5 part per million (ppm) .sup.6Li
isotope stock solution was prepared from the .sup.6Li enriched
isotope solution by diluting the .sup.6Li enriched isotope solution
with deionized water. A tagged ink having a detectable marker was
prepared from the .sup.6Li isotope stock solution by adding 0.1g of
the .sup.6Li isotope stock solution to 50g of ink. The resulting
ink was a 10 ppb .sup.6Li isotope tagged ink which was labeled as
the "authentic" ink.
[0056] A sample of the authentic ink was diluted 100 fold with
deionized water. The diluted samples were introduced into an
Agilent-4500 Inductively Coupled Plasma Mass Spectrometry (ICP-MS)
instrument, obtained from Agilent Technologies of Palo Alto, Calif.
and the cool plasma method was used to measure the isotope mass
counts. The ICP-MS instrumentation and the cool plasma method are
well known to those of ordinary skill in the art and, accordingly,
are not discussed further herein. Cobalt (Co) was added as the
internal standard to compensate for any instrument drift and sample
matrix effect. The instrument was not tuned to optimize the
detection of light masses.
[0057] .sup.6Li isotope and .sup.7Li isotope mass counts, as well
as the ratio of .sup.6Li:.sup.7Li are shown in each of FIGS. 1-5
for the authentic ink. The authentic ink is labeled as 10 ppb
.sup.6Li Tagged Ink.
[0058] A number of different inks were tagged in this manner and
are labeled as ink samples A-E in FIGS. 1-5. Ink sample A was a
black ink, ink sample B was a magenta ink, ink sample C was a
yellow ink, ink sample D was a cyan ink having a first formulation,
and ink sample E was a cyan ink having a second formulation. Each
of the ink samples was prepared for purposes of the experiments at
the San Diego, Calif. facility of Hewlett-Packard Company.
Additionally, a number of the below-described experiments were run
at two separate times. Accordingly, each of ink samples A-E is also
labeled as 1 and 2 to indicate two different runs.
EXAMPLE 2
Preparation of 20% Adulterated Ink
[0059] An ink adulterated by 20% relative to the authentic ink was
prepared by mixing a sample of the authentic ink with an untagged
ink of the same type and color to obtain an 8 ppb .sup.6Li
adulterated ink. Samples of the 20% adulterated ink were diluted
100 fold with deionized water. The diluted samples were introduced
into the Agilent-4500 ICP-MS instrument and the cool plasma method
was used to measure the isotope mass counts. As with the authentic
ink samples, cobalt (Co) was added as the internal standard to
compensate for any instrument drift and sample matrix effect and
the instrument was not tuned to optimize the detection of light
masses.
[0060] The .sup.6Li and .sup.7Li mass counts, as well as the ratio
of .sup.6Li:.sup.7Li are shown in FIG. 1. The 20% adulterated ink
is labeled as 8 ppb .sup.6Li Ink.
[0061] In a first comparison, using the .sup.6Li mass counts of the
authentic ink and the 20% adulterated ink, the ratio of the
.sup.6Li mass count of the adulterated ink to the .sup.6Li mass
count of the authentic ink was determined. These values are shown
for each ink sample in FIG. 1 under the heading .sup.6Li Counts
Adulterated/Authentic.
[0062] If the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was greater
than 0.66, the ink sample was indicated as "Authentic." If,
however, the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was less than
or equal to 0.66, the ink sample was indicated as "Fake 1." As
shown in FIG. 1, each of samples A1, A2, B1, B2, C2, D1, D2, E1,
and E2 was indicated as Authentic and sample C1 was indicated as
"Fake 1."
[0063] In a second comparison, using the .sup.6Li:.sup.7Li ratios
for both the authentic ink and the 20% adulterated ink, the ratio
of the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li :.sup.7Li ratio of the authentic ink was determined. These
values are also shown for each ink sample in FIG. 1 under the
heading .sup.6Li/.sup.7Li Ratios Adulterated/ Authentic.
[0064] If the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li:.sup.7Li ratio of the authentic ink was greater than 0.66,
the ink sample was indicated as "Authentic." If, however, the
.sup.6Li:.sup.7Li ratio of the authentic ink was less than or equal
to 0.66, the ink sample was indicated as "Fake 2." As shown in FIG.
1, each of samples A1, A2, B1, B2, C2, D1, D2, E1, and E2 was
indicated as "Fake 2" and ink sample C1 was indicated as
"Authentic."
[0065] If either of the first or second comparisons yielded an ink
that was indicated as fake (i.e., either "Fake 1" or "Fake 2"), the
ink was designated as counterfeit. As such, at only 20%
adulteration, the methods of the present invention identified each
of the ink samples as counterfeit.
EXAMPLE 3
Preparation of 50% Adulterated Ink
[0066] An ink adulterated by 50% relative to the authentic ink was
prepared by mixing a sample of the authentic ink with an untagged
ink of the same type and color to obtain a 5 ppb .sup.6Li
adulterated ink. Samples of the 50% adulterated ink were diluted
100 fold with deionized water. The diluted samples were introduced
into the Agilent-4500 ICP-MS instrument and the cool plasma method
was used to measure the isotope mass counts. As with the authentic
ink samples, cobalt (Co) was added as the internal standard to
compensate for any instrument drift and sample matrix effect and
the instrument was not tuned to optimize the detection of light
masses.
[0067] The .sup.6Li and .sup.7Li mass counts, as well as the ratio
of .sup.6Li:.sup.7Li are shown in FIG. 2. The 50% adulterated ink
is labeled as 5 ppb .sup.6Li Ink.
[0068] In a first comparison, using the .sup.6Li mass counts of
both the authentic ink and the 50% adulterated ink, the ratio of
the .sup.6Li mass count of the adulterated ink to the .sup.6Li mass
count of the authentic ink was determined. These values are shown
for each ink sample in FIG. 2 under the heading .sup.6Li Counts
Adulterated/Authentic.
[0069] If the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was greater
than 0.66, the ink sample was indicated as "Authentic." If,
however, the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was less than
or equal to 0.66, the ink sample was indicated as "Fake 1." As
shown in FIG. 2, each of the ink samples was indicated as "Fake
1."
[0070] In a second comparison, using the .sup.6Li:.sup.7Li ratios
for both the authentic ink and the 50% adulterated ink, the ratio
of the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li :.sup.7Li ratio of the authentic ink was determined. These
values are also shown for each ink sample in FIG. 2 under the
heading .sup.6Li/7Li Ratios Adulterated/ Authentic.
[0071] If the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li:.sup.7Li ratio of the authentic ink was greater than 0.66,
the ink sample was indicated as "Authentic." If, however, the
.sup.6Li:.sup.7Li ratio of the authentic ink was less than or equal
to 0.66, the ink sample was indicated as "Fake 2." As shown in FIG.
2, each of the ink samples in this experiment was indicated as
"Fake 2."
[0072] If either of the first or second comparisons yielded an. ink
that was indicated as fake (i.e., either "Fake 1" or "Fake 2"), the
ink was designated as counterfeit. As such, at 50% adulteration,
the methods of the present invention identified each of the ink
samples as counterfeit.
EXAMPLE 4
Preparation of 80% Adulterated Ink
[0073] An ink adulterated by 80% relative to the authentic ink was
prepared by mixing a sample of the authentic ink with an untagged
ink of the same type and color to obtain an 2 ppb .sup.6Li
adulterated ink. Samples of the 80% adulterated ink were diluted
100 fold with deionized water. The diluted samples were introduced
into the Agilent-4500 ICP-MS instrument and the cool plasma method
was used to measure the isotope mass counts. As with the authentic
ink samples, cobalt (Co) was added as the internal standard to
compensate for any instrument drift and sample matrix effect and
the instrument was not tuned to optimize the detection of light
masses.
[0074] The .sup.6Li and .sup.7Li mass counts, as well as the ratio
of .sup.6Li:.sup.7Li are shown in FIG. 3. The 80% adulterated ink
is labeled as 2 ppb .sup.6Li Ink.
[0075] In a first comparison, using the .sup.6Li mass counts of the
authentic ink and the 80% adulterated ink, the ratio of the
.sup.6Li mass count of the adulterated ink to the .sup.6Li mass
count of the authentic ink was determined. These values are shown
for each ink sample in FIG. 3 under the heading .sup.6Li Counts
Adulterated/Authentic.
[0076] If the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was greater
than 0.66, the ink sample was indicated as "Authentic." If,
however, the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was less than
or equal to 0.66, the ink sample was indicated as "Fake 1." As
shown in FIG. 3, each of the ink samples was indicated as "Fake
1."
[0077] In a second comparison, using the .sup.6Li:.sup.7Li ratios
for both the authentic ink and the 80% adulterated ink, the ratio
of the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li:.sup.7Li ratio of the authentic ink was determined. These
values are also shown for each ink sample in FIG. 3 under the
heading .sup.6Li/.sup.7Li Ratios Adulterated/ Authentic.
[0078] If the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li .sup.7Li ratio of the authentic ink was greater than 0.66,
the ink sample was indicated as "Authentic." If, however, the
.sup.6Li:.sup.7Li ratio of the authentic ink was less than or equal
to 0.66, the ink sample was indicated as "Fake 2." As shown in FIG.
3, each of the ink samples was indicated as "Fake 2."
[0079] If either of the first or second comparisons yielded an ink
that was indicated as fake (i.e., either "Fake 1" or "Fake 2"), the
ink was designated as counterfeit. As such, at 80% adulteration,
the methods of the present invention identified each of the ink
samples as counterfeit.
EXAMPLE 5
Preparation 50% Diluted Ink
[0080] An ink diluted by 50% relative to the authentic ink with
deionized water was prepared to obtain an 5 ppb .sup.6Li diluted
ink. The 50% diluted ink sample was diluted 100 fold with deionized
water. The diluted sample was introduced into the Agilent-4500
ICP-MS instrument and the cool plasma method was used to measure
the isotope mass counts. As with the authentic ink samples, cobalt
(Co) was added as the internal standard to compensate for any
instrument drift and sample matrix effect and the instrument was
not tuned to optimize the detection of light masses.
[0081] The .sup.6Li and .sup.7Li mass counts, as well as the ratio
of .sup.6Li:.sup.7Li are shown in FIG. 4. The 50% diluted ink is
labeled as 5 ppb .sup.6Li Ink.
[0082] In a first comparison, using the .sup.6Li mass counts of
both the authentic ink and the 50% diluted ink, the ratio of the
.sup.6Li mass count of the adulterated ink to the .sup.6Li mass
count of the authentic ink was determined. These values are shown
for each ink sample in FIG. 4 under the heading .sup.6Li Counts
Adulterated/Authentic.
[0083] If the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was greater
than 0.66, the ink sample was indicated as "Authentic." If,
however, the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was less than
or equal to 0.66, the ink sample was indicated as "Fake 1." As
shown in FIG. 4, each of samples A2, B2 and D2 was indicated as
"Fake 1" and each of samples C2 and E2 was indicated as
"Authentic."
[0084] In a second comparison, using the .sup.6Li:.sup.7Li ratios
for both the authentic ink and the 50% diluted ink, the ratio of
the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li:.sup.7Li ratio of the authentic ink was determined. These
values are also shown for each ink sample in FIG. 4 under the
heading .sup.6Li/.sup.7Li Ratios Adulterated/ Authentic.
[0085] If the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li:.sup.7Li ratio of the authentic ink was greater than 0.66,
the ink sample was indicated as "Authentic." If, however, the
.sup.6Li:.sup.7Li ratio of the authentic ink was less than or equal
to 0.66, the ink sample was indicated as "Fake 2." As shown in FIG.
4, each of samples A2, C2, and D2 was indicated as "Authentic" and
each of samples B2 and E2 was indicated as "Fake 2."
[0086] If either of the first or second comparisons yielded an ink
that was indicated as fake (i.e., either "Fake 1" or "Fake 2"), the
ink was designated as counterfeit. As such, at 50% dilution, the
methods of the present invention identified four out of the five
ink samples as counterfeit. Ink sample C2 was indicated as
"Authentic" in both comparisons indicating possible contamination
or detection error.
EXAMPLE 6
Preparation of 80% Diluted Ink
[0087] An ink diluted by 80% relative to the authentic ink with
deionized water was prepared to obtain an 2 ppb .sup.6Li diluted
ink. The 80% diluted ink sample was further diluted 100 fold with
deionized water. The diluted sample was introduced into the
Agilent-4500 ICP-MS instrument and the cool plasma method was used
to measure the isotope mass counts. As with the authentic ink
samples, cobalt (Co) was added as the internal standard to
compensate for any instrument drift and sample matrix effect and
the instrument was not tuned to optimize the detection of light
masses.
[0088] The .sup.6Li and .sup.7Li mass counts, as well as the ratio
of .sup.6Li:.sup.7Li are shown in FIG. 5. The 80% diluted ink is
labeled as 2 ppb .sup.6Li Ink.
[0089] In a first comparison, using the .sup.6Li mass counts of
both the authentic ink and the 80% diluted ink, the ratio of the
.sup.6Li mass count of the adulterated ink to the .sup.6Li mass
count of the authentic ink was determined. These values are shown
for each ink sample in FIG. 5 under the heading .sup.6Li Counts
Adulterated/Authentic.
[0090] If the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was greater
than 0.66, the ink sample was indicated as "Authentic." If,
however, the ratio of the .sup.6Li mass count of the adulterated
ink to the .sup.6Li mass count of the authentic ink was less than
or equal to 0.66, the ink sample was indicated as "Fake 1." As
shown in FIG. 5, each of the ink samples was indicated as "Fake
1."
[0091] In a second comparison, using the .sup.6Li:.sup.7Li ratios
for both the authentic ink and the 80% diluted ink, the ratio of
the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li:.sup.7Li ratio of the authentic ink was determined. These
values are also shown for each ink sample in FIG. 5 under the
heading .sup.6Li/.sup.7Li Ratios Adulterated/ Authentic.
[0092] If the .sup.6Li:.sup.7Li ratio of the adulterated ink to the
.sup.6Li:.sup.7Li ratio of the authentic ink was greater than 0.66,
the ink sample was indicated as "Authentic." If, however, the
.sup.6Li:.sup.7Li ratio of the authentic ink was less than or equal
to 0.66, the ink sample was indicated as "Fake 2." As shown in FIG.
5, each of samples B2, D2, and E2 was indicated as "Fake 2" and
each of ink samples A2 and C2 was indicated as "Authentic."
[0093] If either of the first or second comparisons yielded an ink
that was indicated as fake (i.e., either "Fake 1" or "Fake 2"), the
ink was designated as counterfeit. As such, at 80% dilution, the
methods of the present invention identified each of the ink samples
as counterfeit.
EXAMPLE 7
[0094] In one embodiment, a detectable marker such as, for example,
an infrared fluorescing agent capable of fluorescing when exposed
to infrared (IR) light, is added to ink such as, for example, ink
for a thermal ink jet printer such that the presence of absence of
the detectable marker may be assayed. The detectable marker is
selected such that the detectable marker does not interfere with
ink performance, is not visible under normal conditions (i.e.,
visible to the naked eye under normal or white light) and does not
cause failure of a device (i.e., a nozzle of an ink jet print head
used to place the ink on a substrate).
[0095] Referring now to FIG. 6, there is shown a molecular diagram
of one embodiment of a detectable marker 100 which may be employed
in the present invention. In one embodiment, the detectable marker
comprises an infrared fluorescing agent such as, for example,
TINOLUX BBS. In other embodiments, the detectable marker may
comprise any other detectable marker capable of fluorescing when
exposed to infrared (IR) light such as for example, metal
phthalocyanines including zinc, cadmium, tin, magnesium, europium,
aluminum, and combinations of any thereof. In yet another
embodiment, the detectable marker may comprise
1,1',3,3,3',3'-hexamethylindotricarbocyanines or
1,1',3,3,3',3'-hexamethylindodicarbocyanines.
[0096] The ink to which the detectable marker is added may comprise
one of the inks conventionally used in an ink jet printer (i.e.,
yellow (Y), magenta (M), cyan (C), black (K), a transparent ink, or
combinations of any thereof). In other embodiments, the detectable
marker may be added to other substances used in the printing
industry, such as, for example, fixer, clear ink, or an optimizing
solution, and may be added to inks used in any type of printer.
[0097] In one embodiment, the TINOLUX BBS was added to transparent
ink, yellow ink, magenta ink, cyan ink, and black ink designed for
use in an HP DesignJet 5500 printer. As conventionally known, the
colored inks (i.e., yellow ink, magenta ink, cyan ink, and black
ink) each include at least one colorant that is visible under
visible light and that imparts color to the ink. The TINOLUX BBS
was added at a concentration of about 50 ppm (parts per million).
In other embodiments, the TINOLUX BBS or other infrared fluorescing
agent may be added to the ink at a concentration of between about
10 ppm and about 10000 ppm. The concentration of the infrared
fluorescing agent in the ink should be such that the infrared
fluorescing agent is detectable, but does not affect the print
quality of the ink.
EXAMPLE 8
[0098] In another embodiment, a method of testing an unidentified
ink for authenticity includes subjecting the unidentified ink to a
separation procedure such as, for example, thin layer
chromatography, and subjecting the separated ink to infrared light.
The separation procedure separates any colorant (i.e., dye or
pigment) in the ink from the detectable marker such that the
detectable marker may be detected. In this manner, if the ink
includes an infrared fluorescing agent as the detectable marker,
the infrared fluorescing agent will fluoresce when subjected to
infrared light, thus, indicating that the ink is authentic. If the
ink does not include the infrared fluorescing agent, the ink may be
deemed to be non-authentic.
[0099] In other embodiments, the separation procedure may include
other conventional chromatography procedures such as, for example,
liquid chromatography. In a further embodiment, the separation
procedure may include placing the ink on a separation material,
such as a filter, or other conventional separation procedures.
[0100] In an additional embodiment, the separation procedure may be
omitted and the ink, including the detectable marker, may be
subjected to the infrared light This embodiment is applicable to
inks or substances that do not include a colorant (e.g.,
transparent ink or fixer) or includes a colorant that does not
prevent the detectable marker from being seen (e.g., yellow ink or
magenta ink) when subjected to the infrared light.
[0101] In one embodiment, the transparent ink and colorant-based
inks including yellow ink, magenta ink, cyan ink, and black ink
were prepared, wherein each ink included the infrared fluorescing
agent TINOLUX BBS at a concentration of about 50 ppm. Each of the
transparent ink, the yellow ink, the magenta ink, the cyan ink, and
the black ink were placed on a reverse phase Thin Layer
Chromatography Plate such as, for example, a TLC Whatman, KC 18. A
solvent such as, for example, methanol/water was used as a mobile
phase to separate the TINOLUX BBS from the components of the
transparent ink, yellow ink, magenta ink, cyan ink, and black ink,
wherein the separation Rf was selected to be about from about 0.2
to about 0.9.
[0102] In other embodiments, the solvent may comprise acetonitrile,
dichloromethane (DCM), hexane, acetone, other alcohol solvents,
such as, for example, ethanol or propanol, or any combinations
thereof, wherein the concentration of the solvent is from about 20%
to about 95% in a normal separation. Other types of Thin Layer
Chromatographies (TLC) that may be used to separate the infrared
fluorescing agent from the ink ingredients or components include,
but are not limited to, cellulose, aluminum oxide, silica gel,
polyamide normal phase TLC, or C-8, C-18 reversed phrase TLC.
[0103] Ink components 101 of each of the transparent ink, the
yellow ink, the magenta ink, the cyan ink, and the black ink were
separated, as shown in the patterns of FIG. 7, when illuminated
with visible light, such as, white light. The transparent ink was
separated in lane 102, the yellow ink was separated in lane 104,
the magenta ink was separated in lane 106, the cyan ink was
separated in lane 108, and the black ink was separated in lane
110.
[0104] The separated inks in each of lanes 102, 104, 106, 108, and
110 were subjected to infrared light and viewed with an infrared
viewer, as illustrated in FIG. 8. A fluorescent area 124 in each of
the lanes 102, 104, 106, 108, and 110 represents the TINOLUX BBS
which is visible when subjected to the infrared light source and
viewed with the infrared viewer.
[0105] In one embodiment, the infrared viewer comprises a single
chip black and white camera with an infrared blocking viewer of the
camera removed. The specifications of the single chip black and
white camera used in this embodiment are as follows: a center
wavelength of about 710 nm (nominal), wherein .ltoreq.0.01% T is
blocked at about 400 nm to 650 nm and at about 775 nm to 1200 nm.
The specifications of the infrared light source used in this
embodiment are as follows: a center wavelength of about 649 nm
(nominal), wherein at least 60% of the light is transmitted and
.ltoreq.0.01% T is blocked at about 400 nm to 600 nm and at about
700 nm to about 1000 nm.
EXAMPLE 9
[0106] In a further embodiment, the infrared fluorescing agent may
be mixed with an ink having a pigment or the colorant to produce an
authentic ink. In this embodiment, the method for testing the
unidentified ink for authenticity includes subjecting the
unidentified ink to a separation procedure such as, for example,
Thin Layer Chromatography, and subjecting the separated ink to
infrared light. The separation procedure separates any pigments in
the unidentified ink from the detectable marker such that the
detectable marker may be detected. In this manner, if the ink
includes an infrared fluorescing agent as the detectable marker,
the infrared fluorescing agent will fluoresce when subjected to
infrared light and indicate that the ink is authentic. If the ink
does not include the infrared fluorescing agent, the ink may be
deemed to be non- authentic.
[0107] In one embodiment, TINOLUX BBS was added to dark cyan and
light cyan pigmented inks at a concentration of about 100 ppm. The
pigmented inks including the TINOLUX BBS were subjected to Thin
Layer Chromatography (i.e., a C-18 reverse phase, using 70% MeOH as
the solvent). The separated pigmented inks were viewed with visible
light, as illustrated in FIG. 9A, where dark cyan was run in lane
120 and light cyan was run in lane 122. FIG. 9B illustrates the
separated inks of FIG. 9A viewed under infrared light. The location
of the TINOLUX BBS in the two lanes is illustrated at light areas
124.
EXAMPLE 10
[0108] A system of authenticating an unidentified ink includes a
separation means for separating components of the unidentified ink
from the detectable marker, an infrared light source for subjecting
the separated unidentified ink or the unidentified ink to infrared
light, and an infrared viewer for causing the detectable marker to
fluoresce, if present, under infrared light. The system may be
configured to be mobile (i.e., portable) such that the system may
be used in the field to authenticate or detect unidentified inks.
In this manner, an ink jet technician may take an ink sample from
an ink cartridge at a store and subject the ink sample to testing
to see if the ink is authentic (i.e., whether the ink includes the
detectable marker in the proportions placed in the ink when the ink
is manufactured).
[0109] By employing the inks including detectable markers, methods
and systems described herein, an ink manufacturer or vendor may
distribute the authentic inks in commerce and test inks to ensure
that the inks are authentic. In this manner, the manufacturer or
vendor may reduce the incidence of counterfeiting or deter
counterfeiters from trying to replicate the authentic ink produced
by the manufacturer or sold by the vendor.
[0110] Although the present invention has been shown and described
with respect to various exemplary embodiments, various additions,
deletions, and modifications that are obvious to a person of
ordinary skill in the art to which the invention pertains, even if
not shown or specifically described herein, are deemed to lie
within the scope of the invention as encompassed by the following
claims. Further, features or elements of different embodiments may
be employed in combination.
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