U.S. patent application number 11/195499 was filed with the patent office on 2005-12-01 for identification particles and system and method for retrospective identification using spectral codes.
Invention is credited to Brogger, Brian, Kerns, William J..
Application Number | 20050264001 11/195499 |
Document ID | / |
Family ID | 27400925 |
Filed Date | 2005-12-01 |
United States Patent
Application |
20050264001 |
Kind Code |
A1 |
Kerns, William J. ; et
al. |
December 1, 2005 |
Identification particles and system and method for retrospective
identification using spectral codes
Abstract
A system and method using reporter elements provides
retrospective identification of articles. An article is marked with
reporter elements such that the mark has a characteristic spectral
response when exposed to energy stimulation. To verify the
authenticity of the article, a reader scans the mark containing the
reporter elements and obtains a spectral signature. The reader then
compares the detected signature to the characteristic signature to
determine the authenticity or identity of the marked article.
Inventors: |
Kerns, William J.; (New
Brighton, MN) ; Brogger, Brian; (Blaine, MN) |
Correspondence
Address: |
KAGAN BINDER, PLLC
SUITE 200, MAPLE ISLAND BUILDING
221 MAIN STREET NORTH
STILLWATER
MN
55082
US
|
Family ID: |
27400925 |
Appl. No.: |
11/195499 |
Filed: |
August 1, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11195499 |
Aug 1, 2005 |
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10023472 |
Dec 17, 2001 |
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10023472 |
Dec 17, 2001 |
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09897553 |
Jul 2, 2001 |
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09897553 |
Jul 2, 2001 |
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09283174 |
Apr 1, 1999 |
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6309690 |
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60256209 |
Dec 15, 2000 |
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Current U.S.
Class: |
283/81 |
Current CPC
Class: |
G06K 19/06046 20130101;
G01N 21/31 20130101; A63B 45/02 20130101; G07F 7/12 20130101; G07F
7/122 20130101; G07F 7/08 20130101; G09F 3/00 20130101; G06K
2019/06234 20130101; G06K 19/06009 20130101; A63B 2225/15
20130101 |
Class at
Publication: |
283/081 |
International
Class: |
B42D 015/00 |
Claims
1-20. (canceled)
21. An identification system, comprising a) a particle
incorporating a code; b) a carrier material entraining the
particle; and c) a reporter element incorporated into the
entraining carrier material, said reporter element emitting a
spectral signature responsive to energy stimulation.
22. The system of claim 21, wherein the particle incorporates a
sequence of colored layers, wherein the sequence of the colored
layers provides the code.
23. The system of claim 21, wherein the reporter element is
phosphorescent.
24. The system of claim 21, wherein the reporter element is
fluorescent.
25. The system of claim 21, wherein the reporter element is
photochromic.
26. The system of claim 21, wherein the reporter element is
thermochromic.
27. The system of claim 21, wherein the reporter element is an
up-converting phosphorescent material.
28. The system of claim 21, wherein the reporter element emits a
spectral signature responsive to an infrared energy
stimulation.
29. The system of claim 21, wherein the reporter element is a
semiconducting nanocrystal.
30. The system of claim 21, wherein at least two reporter elements
are incorporated into the entraining carrier material, said two
reporter elements having a different spectral response to energy
stimulation.
31. A method of making a coded particle, comprising the steps of:
a) causing a coded particle to be entrained in a carrier material;
and b) causing a reporter element to be entrained in the carrier
material.
Description
[0001] This application is a continuation-in-part of U.S. Ser. No.
09/897,553, filed Jul. 2, 2001 which is a divisional application of
U.S. Pat. No. 6,309,690, issued Oct. 30, 2001 and filed Apr. 1,
1999 and a continuation of provisional application U.S. Ser. No.
60/256,209, filed Dec. 15, 2000. Priority is claimed to these
applications.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the marking of
articles for retrospective identification or authentication and
more particularly to systems and methods for marking an article
with spectrally coded material and using the characteristic
spectral signature of the coded material to retrospectively
identify or verify authenticity of marked articles.
BACKGROUND OF THE INVENTION
[0003] Authentication and identification of articles is of great
concern in a number of arenas. For example, customs agents attempt
to stop shipments of counterfeit goods when they enter the country.
To do so, they must be able to distinguish between genuine or
authorized goods and counterfeit or unauthorized goods. Attempts
have been made to mark authorized goods and/or their shipment
containers and to provide a system for officials to use the marks
to confirm the authenticity of the goods.
[0004] Many applications for authenticity-verifying or
source-verifying technology require or are benefited from solutions
which are easily implemented by a person "in the field". Other
applications are benefited from solutions which are easily
automated to allow fast yet more complete, rather than
spot-checked, reviews of larger numbers of articles.
[0005] What has been needed has been an authentication system with
protections against counterfeiting and with ease of use and access
for customs officials, law enforcement, and other interested
persons to verify the authenticity of articles. The system and
method should allow the user several different methods to
authenticate or identify an item. A needed system and method should
have varying levels of security, such that a first magnified
"eyeball" review provides some level of assurance that the goods
are authentic; additional covert features which are more difficult
to verify and more difficult to counterfeit offer further levels of
security. Further, the system should be conducive or adaptable to
"in the field" applications using hand held or portable
verification or reading equipment. Still further, it is
advantageous for an authentication system to be adaptable to
automation, such that articles can be scanned and authenticated
quickly and accurately while minimizing human labor.
SUMMARY OF THE INVENTION
[0006] In a preferred system and method according to the present
invention, one or more reporter elements is applied to an article,
item or a label for which retrospective identification is desired.
Upon excitation or stimulus, such as from an energy source, the
reporter elements yield a spectral "signature" that characterizes
the reporter elements' response to the stimulus. To verify the
authenticity of the subject article, the microparticle mark is
scanned with a device that "reads" the spectral signature of the
reporter elements and determines whether the detected signature
matches the pre-defined signature. The reader displays an
indication that the article is authenticated.
[0007] In another embodiment, the spectral signature of reporter
elements to be applied to an article is read, and is translated via
an algorithm to a printable code, such as an alpha-numeric code or
a bar code, that is then printed on the article or on the label
bearing the mark. The detector uses the same algorithm to decipher
the code and displays this deciphered code, and the user then reads
the code displayed on the reader device and compares that to the
printed code. If the deciphered code matches the printed code, then
the article is authentic. As an additional feature, a serial number
or otherwise unique code is added to the deciphered code from the
spectral signature. In this manner, each marked article is uniquely
identifiable by its serial number, as well as batch identifiable by
its spectral code.
[0008] Preferably, one or more reporter elements are incorporated
into one or more layers of a microcoded particle or are applied in
conjunction with a microcoded particle.
[0009] The system and method of the present invention can be used
in conjunction with the pattern recognition in the manner described
in U.S. Ser. No. 09/283,174, filed Apr. 1, 1999, issued as U.S.
Pat. No. 6,309,690, incorporated herein by reference in its
entirety.
[0010] In another preferred embodiment, the microparticles have
distinctly colored layers and the sequence of the colored layers
forms a code that is assigned to a particular meaning, such as the
source or identity of goods marked with the particles. The colors
of the microparticles may be selected advantageously to have some
common association to the article.
[0011] In another preferred embodiment, the microparticles have
indicia on or below the surface of the particle. Preferably the
indicia is embossed, laser etched, photo reduction, or the
like.
[0012] These preferred embodiments enable a variety of methods of
"interrogating" the microcoded marks to confirm the authenticity of
the article. Some of the embodiments have at least one level of
security that can be viewed and assessed with simple magnification.
Other embodiments require exposure of the mark to an energy
stimulus, such as temperature changes, light, or electric current
induced by magnetic field.
[0013] These preferred embodiments enable varying degrees of
security against counterfeit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] An exemplary version of a microcoded mark and a system and
method for authenticating articles is shown in the figures, wherein
like reference numerals refer to equivalent structure throughout,
and wherein:
[0015] FIG. 1 is a schematic illustration of a system and method
for marking an article for retrospective identification with
reporter elements;
[0016] FIG. 1a is a schematic illustration of a system and method
for marking an article for retrospective identification with
reporter elements and a printable code computed from the spectral
response of the reporter elements;
[0017] FIG. 2 is schematic illustration of the generation of a
spectral signature for spectral code containing three types of
reporter elements;
[0018] FIG. 3 is a schematic illustration of an alternate version
of the system and method illustrated in FIG. 1;
[0019] FIG. 4 is a schematic illustration of a system and method
for interrogating a label to determine its authenticity, where the
label or article has been marked in accord with the system and
method of FIG. 1a;
[0020] FIG. 5 is a schematic illustration of a system and method
for interrogating a label to determine its authenticity, where the
label or article has been marked in accord with the system and
method of FIG. 1a and with a bar code;
[0021] FIGS. 6a-6d are schematic illustrations of alternate
arrangements for incorporating reporter elements in one or more
layers of a microparticle or microcoded particle;
[0022] FIG. 7 is a an enlarged side view of a microparticle used in
accordance with the present invention; and
[0023] FIG. 8 is an enlarged perspective view of an embodiment of a
microparticle used in accordance with the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)
[0024] A preferred system and method for retrospective
identification of an article 5 or a container of articles using
spectral signatures according to the present invention is
illustrated schematically in FIGS. 1-6. FIG. 1 illustrates a
magnified mark 12 that is generally undecipherable to the naked
eye. That is, it may be apparent that the mark is present, but the
detailed aspects of the mark are not visible without magnification
or digital imaging. The mark 12 incorporates reporter elements 14.
A reporter element 14 is any atom, molecule, crystal, polymer or
other compound or the like that interacts with a form of energy,
such as light, to give a detectable light emission or absorption
response. Reporter elements 14 are described in greater detail
below in the section entitled "Reporter Elements". Examples of the
many manners in which reporter elements 14 can be incorporated into
the mark 12 and the materials that can be used for reporter
elements 14 will be described in greater detail below.
[0025] The mark 12 can be applied to, affixed to, mixed into, or
otherwise connected to the article 5 to be retrospectively
identified. Of course, the manner of that connection will be
determined in many cases by the nature of the article 5. For
example, if the article 5 is a powdered material, such as that used
in an explosive compound, the reporter elements 14 can be directly
mixed into the powder. Alternatively, as will be described below,
the reporter elements 14 can be embedded within a microcoded
particle, and these microcoded particles can be mixed into the
explosive powder. For other applications, it will be desirable to
affix the reporter elements (within a microcoded particle or alone)
to a label that is adhered to an article. Still further, it may be
desirable to incorporate the reporter elements (within a microcoded
particle or alone) in an adhesive or an ink, or the like which is
then applied to a label or article, as depicted in FIG. 1a.
Microcoded particles or microparticles are described in greater
detail below in the sections entitled "Microcoded Mark", and the
incorporation of reporter elements within a microcoded particle is
described below in the "Reporter Elements" section.
[0026] Preferably reporter elements of one or more types are mixed
to yield a batch of "spectral code" 16. Each type of reporter
element has a characteristic absorption/emittance response to
energy stimulation. Variable concentrations of reporter elements
can be used to provide unique emission intensities. The spectral
signature of a mix of two or more elements contains the additive
combination of the spectral response signatures of each included
element or type. Typically, this additive combination yields a
response and peak over one wavelength range for one element, and a
response and peak over another wavelength range for a second
element, and so on. In other words, the types are chosen such that
their responses are distinct; each type responds across a different
wavelength than other type or types within the batch.
[0027] As illustrated in FIG. 2, a sample 18 of the batch of
spectral code 16 is exposed to an energy excitation source 20, such
as light or heat, to which the reporter elements A, B, and C 14
respond. A spectral analyzer 22 reads the response of the reporter
elements 14 and generates a spectral signature 25 displayed in a
graph showing intensity as a function of wavelength. Alternatively,
the analyzer generates a spectral signature displayed in a graph of
intensity as a function of frequency or wavelength. As another
alternative, the spectral signature could be displayed in a graph
of the sum of two or more of these functions or other mathematical
manipulation of any of these signatures or combinations of the
signatures.
[0028] Each type of reporter element 14 shows a maximum or peak
response within or across a predetermined range of wavelengths. In
the illustrated example, three types of reporter elements, A, B and
C, yield three corresponding maximum intensity peaks I.sub.A,
I.sub.B and I.sub.C at wavelengths .lambda..sub.A, .lambda..sub.B
and .lambda..sub.C, respectively. The intensity of the response of
each type of reporter element 14 depends upon its concentration in
the sample 18. Upon interrogation, a detector is used to observe
the spectral response of mark made of sample 18. The detector
preferably provides an indication of whether the detected signature
meets the pre-defined signature for sample 18.
[0029] The system and method can use either or both of the
parameters of wavelength and intensity to characterize the spectral
signature of a sample 18. In other words, the signature might be
defined such that an intensity peak must be exhibited at a
particular wavelength or between a range of wavelengths, but the
actual values of the intensity might be ignored. Alternatively, for
added security or precision in identification, the signature might
be defined such that a particular intensity maximum must be
exhibited at a specified wavelength or within a range of
wavelengths. As another alternative, the intensity alone might be
used: i.e., if the intensity of the response is not at or
sufficiently near a specified intensity value, then the conclusion
can be drawn that the specified reporter element is not present in
the concentration required of an authentic sample.
[0030] For some types of reporter elements 14, other aspects of a
spectral signature can be used. For example, the spectral response
of fluorescent or phosphorescent materials is time-dependent, with
the maximum intensity of its response diminishing over time after
the removal of an energy stimulus. Thus, these materials have a
characteristic half-life. The time-dependent signature can be
characterized through relatively rapid serial analysis of the
emission signal.
[0031] An optional feature which offers additional security
advantages includes the transposition of the spectral signature
into an alpha-numeric code or other type of printable code, such as
a bar code. This is illustrated in FIG. 1a in conjunction with an
application involving a mark on a label 10', though this printed
code aspect might also be used in conjunction with applications
that do not involve a label. As illustrated in FIG. 1a, the
spectral signature 25' is filtered through an algorithm 30' to
transpose the signature 25' into a printable code 50', such as an
alpha-numeric code or a bar code. A printer 40' prints this
printable code 50' on the label 10'. Further, the printable code
50' is stored in a database 60' in conjunction with a description
of the goods on which the printable code 50' is placed. Optionally,
the database 60' may assign a unique identifier 70', such as a
serial number, to the article and the printer 40' can print that
unique identifier 70' on the label 10'. In one embodiment, the
serial number 70' and the printable code 50' are joined into one
string (alpha-numeric, bar-code or other) that is printed on the
label 10'. Optionally, the label 10' also includes human-readable
written identification or description 80' of the goods.
[0032] FIG. 3 illustrates an alternative order for initial steps in
the marking of an article. In the FIG. 3 embodiment, the mark 12 is
first applied to the article 5 (or on a label 10') and then scanned
by a spectral analyzer 22 to determine the spectral signature of
the mark 12, or more specifically of the reporter elements 14 in
the mark 12. The rest of the system and process depicted in FIG. 3
is the same as that depicted in FIG. 1 and described above.
[0033] FIGS. 4 and 5 illustrate ways that an article 5, marked in
the manner illustrated in FIG. 1a, can be interrogated to determine
the authenticity of the article 5. As shown in FIG. 4, a reader or
detector 100' images the mark 12' and computes the printable code
50' by performing the designated algorithm 30' on the spectral
signature. A display 105' on the reader 100' displays the computed
code. The user 110' views and compares the computed code with the
code 50 printed on the article or on a label 10' affixed to the
article. In the illustrated case, the mark and code both appear on
a label 10' which is coupled with the article to be identified. If
the codes match, then the article is legitimate. Preferably, in a
label configuration, the label 10' is tamper-evident, such that if
a legitimate label is removed from its original location, the mark
12' is destroyed or altered, such that spectral analysis and
decoding of the altered mark 12' will not yield a computed code
that matches the printed code 50'.
[0034] In another embodiment, illustrated in FIG. 5, a reader 150'
scans the mark 12 and a serialized barcode 155' printed on the
article or a label affixed to the article. If these components
"match", then the reader 150' gives an indication of a match, such
as with an indicator light 160'. The components match if they are
stored in conjunction with one another in the database 60'.
[0035] FIGS. 4 and 5 illustrate analysis via a generally portable
device, with the mark 12 being reviewed without disturbing its
attachment to the article. In some cases, however, it may be
advantageous to extract the reporter elements to perform other
types of analysis not conducive to portable equipment or to "in the
field" methods or technology.
[0036] Technology and methods that can be used for spectral
analysis are well known to those of skill in the art, and include,
for example: chromatography, mass spectroscopy, nuclear magnetic
resonance, infrared spectroscopy, ultraviolet/visible spectroscopy,
flame ionization, electrical analysis, thermal analysis,
hybridization assays, gel elctrophoresis.
[0037] Reporter Elements
[0038] As described above, a reporter element can be any molecule,
crystal, atom or compound, including polymers, that, when
stimulated by energy, yield a detectable energy, mass or other
response. For light responsive reporter elements, materials can be
used which are responsive to any desired frequency or wavelength.
The response of the reporter element is dependant upon the material
of the reporter element as well as the energy stimulus provided but
typical responses include fluorescence, phosphorescence,
upconverting phosphorescence, absorption and emission.
[0039] As will be understood, the material used for the reporter
element, the appropriate energy stimulus, and the response of the
reporter element are copescetic. The following chart provides
examples of materials, energy stimuli and responses:
1 Material - Any material from the following family of materials:
Energy Stimulus Response Flourescents Light Light (Fluorescence)
Phosphorescents Light Light (Phosphorescence) Upconverting Light
Light phosphorescents Photochromics Light Light of predetermined
wavelength Thermochromics Heat/Cold Light Electrochromics Electric
current Light Infrared fluorescents Light in infrared Light
(Fluorescence) wavelengths Infrared phosporescents Light in
infrared Light (Phosphorescence) wavelengths Near-infrared
fluorescents Light in Light (Fluorescence) near-infrared
wavelengths Semi-conducting Light Light nanocrystals (e.g. from the
group II-VI such as cadmium selenide CdSe, magnesium selenide MgSe,
calcium selenide CaSe, barium selenide BaSe, zinc selenide ZnSe)
Magnetic resonance Magnetic field Nuculear magnetic molecules
resonance (NMR) frequencies Isotopic isomers or really Electrical
energy Mass detection any atom, ion, molecule
[0040] The semiconducting nanocrystal family offers advantages of
stability (i.e. increased shelf life), relatively narrow emission
spectra, relatively broad excitation spectra, and can be excited
without laser-generated light.
[0041] As illustrated in FIG. 6, reporter elements 14 can be
implemented in combination with a microcoded particle or substrate
in a variety of ways to form an identification particle. Generally,
a microcoded particle is a multilayered particle. Microcoded
particles are described in greater detail below.
[0042] FIG. 6a shows a microcoded particle 200, with reporter
elements 214 entrained in the outer layers 220 and 221 of the
particle 200.
[0043] FIG. 6b shows an arrangement wherein reporter elements 214
are entrained in carrier material 230, such as adhesive, ink or
other material, in which microparticles 225 are entrained, but
where the reporter elements 214 are separate and distinct from the
microparticles 225.
[0044] FIG. 6c shows an arrangement wherein one type of reporter
element is incorporated into one layer of a microparticle 250. More
specifically, reporter element 214A is entrained in a first layer
260; reporter element 214B is entrained in second layer 270; and
reporter element 214C is entrained in third layer 280.
[0045] FIG. 6d shows an arrangement wherein a single layer
substrate 290 contains the reporter elements 214, preferably of two
or more types 214A, 214B, 214C. In some applications, it may be
advantageous to add embossing of a bar code or other indicia to the
surface of the substrate for additional identification
properties.
[0046] While all of these examples of FIGS. 6a-6d illustrate the
incorporation of three types of reporter elements, it will be
understood that any number of reporter elements can be used. For
the example of FIG. 6c, the layers could contain the same type of
reporter element, but in varying concentrations in adjacent layers.
Further, the microcoded particle might contain one or more layers
without any reporter elements therein.
[0047] The Microcoded Mark
[0048] The use of microparticles for the retrospective
identification of articles is known from U.S. Pat. Nos. 4,053,433
and 4,390,452, incorporated herein by reference, and from other
sources. Such particles may be used for the identification of a
wide variety of items. Each microparticle includes a sequence of
visually distinguishable dyed and/or pigmented layers. The
microparticles are "coded" in the sense that particular color
sequences in the particles are assigned to a particular meaning,
such as the source of the item on which the particles are placed.
Typically, microparticles are not "readable" to the naked eye, i.e.
the particles must be magnified for the layer sequence to be
discerned.
[0049] FIG. 7 shows a microparticle 1090. The particle 1090 has top
and bottom surfaces 1091 and 1092, with two or more layers 1093,
1094 therebetween. An edge 1095 extends between the top and bottom
surfaces and circumscribes the particle. The edge 1095 is generally
irregular. While the depicted microparticle has only two layers,
the microparticle may contain any number of layers.
[0050] In a preferred embodiment, energy-sensitive materials, such
as thermochromic or photochromic materials, may be used for one or
more of the layers. An energy-sensitive material has different
optical properties under different conditions. For example, a
thermochromic material is transparent in one temperature range, but
opaque outside of that range. Photochromic material can be
transparent or one color under white light of a range of
frequencies, but a different color when exposed to light outside of
that range of frequencies. Use of energy-sensitive material for all
of the layers aids in making the microcoded mark covert. That is,
if the layers are of thermochromic material having the property of
being transparent at room temperature, and if the particles are
entrained in a generally transparent adhesive or epoxy, then the
microcoded mark will be generally covert at room temperature. The
mark and the sequence of its colored layers can be revealed by
exposing the mark to an elevated or decreased temperature,
depending upon the predetermined properties of the thermochromic
material.
[0051] In another preferred embodiment, near-infra-red-frequency
material is used in the microparticle. Such material flouresces
when exposed to infra-red light. Use of this material aids in
making the microcoded mark covert. Currently, known infra-red
materials lose their responsiveness over time upon exposure to UV
light. Therefore, in a preferred embodiment of these
microparticles, a near-infra-red-frequency layer is covered by or
sandwiched between energy sensitive layers that are opaque at
typical indoor ambient temperatures to protect the near-infra-red
material from exposure to UV light under typical temperature
conditions, thereby prolonging the life of the near-infra-red
material.
[0052] In another preferred embodiment, magnetic materials or other
materials that exhibit unique NMR spectrum are used in the
microparticle.
[0053] In another embodiment, the microcoded particle may be a one
or more layers that may be clear or colored and may include indicia
thereon. The indicia may be produced by laser etching, embossing,
photo reduction, or the like. Reporter elements may be entrained in
the layer or substrate.
[0054] In another preferred embodiment, illustrated in FIG. 8, an
outer surface or visible layer 1096 of the multi-layered
microparticle 1097 bears indicia 1098, such as alpha-numeric
characters, patterns, abstract images or the like. The indicia are
preferably registered. A typical method of forming microparticles
bearing indicia yields slightly recessed indicia. Such a method
involves laser etching or embossing of the indicia onto the outer
surface of the microparticles. Another such method is described in
U.S. Pat. No. 4,390,452. To enhance the visibility of the recessed
indicia, the method may also include a step of applying a curable
ink to the indicia-bearing surface, wiping the ink away, leaving
ink settled in the recesses, while leaving the un-recessed area
substantially ink-free. When a curable ink is used, the particle
can then be cured, and the ink will solidify and the ink-filled
indicia are then more easily discernable. For example, inks that
cure upon exposure to ultraviolet can be used.
[0055] The "code" of the microparticles aids in the retrospective
identification of the article because a particular code can be
assigned to a specific article, application or customer. The code
is retired, and particles bearing this sequence or indicia will not
be used in a conflicting manner. Retrospectively, the microcoded
mark can be viewed under magnification and, using information
stored in a database, matched with the information relating to that
particular color sequence or indicia revealing that the article
matches the article to which that sequence is assigned.
[0056] The Detector
[0057] A reader or detector 100, 100' or 150 incorporates hardware
that links it to the computer on which the algorithm 30 and
database 60 are stored so that it can access the relevant algorithm
30 as well as data from the database 60 regarding the subject
goods, such as a textual description or serial numbers. This link
can be made via the internet or via hardwire or any other method of
transferring digital information. Preferably, security features
allow access to the database and algorithm only to selected
users.
[0058] The detector can also be used to read barcodes on labels,
identify the location of reporter elements in a microcoded
particle. The detector may include a video monitor to view an image
of the area being examined or display the results of each test.
[0059] The preferred detector contains an excitation source to
provide the stimulus needed to generate the signature response from
the reporter elements.
[0060] One embodiment of the detector includes a cycling mechanism
such that the excitation stimulus and response detection are pulsed
or timed. This offers particular advantage when used to detect
half-life signatures.
[0061] Preferably, a detector is capable of detecting a wide range
of wavelengths of light to accommodate a variety of types of
reporter elements. Filters, photomultipliers, resistors and the
like can be used to accomplish this.
[0062] Preferably, the detector has circuitry that allows for the
analysis of the spectral signature in a variety of ways. At a basic
level, if all types of expected reporter elements are present, the
detector yields a "yes" or "no" answer. A more sophisticated
detector yields more detailed analysis, such as indicating the
presence of individual types of reporter elements.
[0063] The detector can indicate whether the detected reporter
elements "match" the expected, predefined signature in various
ways. For example, colored LEDs can be incorporated. Red and green
LEDs can be used to indicate a yes/no determination. Alternatively,
several LEDs of various colors can correspond to each colored layer
in a microcoded particle.
[0064] Although an illustrative version of the method and system is
described below, it should be clear that many modifications to the
method and system may be made without departing from the scope of
the invention as expressed in the appended claims.
[0065] Throughout this description, the following terms include the
meanings ascribed to the terms by those of ordinary skill in the
art and includes meanings now understood and those yet to be
discovered or applied; the terms include, but are not limited to,
at least the following illustrative meanings:
[0066] Data means textual, numeric, graphic, symbolic or any other
information.
[0067] Input device includes a keyboard, mouse, track ball, stylus,
touch-sensitive screen, touch-sensitive cursor or mouse pad, or
voice receiver and recognition apparatus/software or any other
device now known or yet to be developed for a human to interact
with a digital storage medium to input or access data stored
therein.
[0068] Storage medium means any method of storing information for
later use, particularly in connection with digitized information,
including but not limited to a floppy disk, a hard drive, digital
tape, and compact disk.
[0069] Network means any connection between two computers by which
one computer can send or access information stored on another
computer, including but not limited to hard-wired connection,
modem/phone line connection, modem/satellite connection, and RF
connection.
[0070] Database means an organization and storage system for
records, wherein one or more pieces of information are stored for
each record.
[0071] Indicia or indice means numeric characters, alpha-numeric
characters, Roman numerals, abstract images, barcodes, logos,
patterns and the like. Indices may be serialized or not
serialized.
[0072] Label means an image-bearing medium, whether optical or
mechanical, including but not limited to paper, foil, or
multi-layer configurations.
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