U.S. patent application number 11/071905 was filed with the patent office on 2005-10-20 for low visual impact labeling method and system.
Invention is credited to Mondie, George R..
Application Number | 20050230469 11/071905 |
Document ID | / |
Family ID | 22983003 |
Filed Date | 2005-10-20 |
United States Patent
Application |
20050230469 |
Kind Code |
A1 |
Mondie, George R. |
October 20, 2005 |
Low visual impact labeling method and system
Abstract
A method of forming symbols, characters, and other images from a
light polarizing material including machine readable indicia
enabling automated identification of articles is disclosed. A light
polarizing material is applied over a reflective layer in a machine
readable pattern. The material may be an image imprinted on a label
with a light polarizing material on a substrate such as a
transparent oriented film. In one aspect, a mail processing system
includes a computer including a database of destination codes
corresponding to a plurality of mail pieces for delivery to at
least some of the destination codes. A media applicator utilizes
the database for generating and applying a light polarizing
material to a label or article to form a machine readable indicia,
including the destination code for each of the plurality of mail
pieces. A mail sorting system utilizing the label includes a camera
with polarized lenses for filtering light reflected from indicia
formed from a light polarizing material on the label. A detector
associated with each of the lenses for detecting reflected light
and generating a signal in response thereto. Signals from the
detector are compared by a computer that produces an electronic
image or pattern corresponding to the machine readable indicia and
generates a sorting signal based upon the indicia which is
transmitted to a mail sorter where the mail pieces are sorted.
Inventors: |
Mondie, George R.; (Bedford,
TX) |
Correspondence
Address: |
PHILIP G. MEYERS LAW OFFICE
1009 LONG PRAIRIE ROAD, SUITE 300
FLOWER MOUND
TX
75022
US
|
Family ID: |
22983003 |
Appl. No.: |
11/071905 |
Filed: |
March 4, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11071905 |
Mar 4, 2005 |
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10033735 |
Dec 28, 2001 |
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6892949 |
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60258986 |
Dec 29, 2000 |
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Current U.S.
Class: |
235/375 ;
235/462.02; 235/491 |
Current CPC
Class: |
G09F 3/0297
20130101 |
Class at
Publication: |
235/375 ;
235/462.02; 235/491 |
International
Class: |
G06F 017/00; G06K
007/10; G06K 019/06; G06K 019/00 |
Claims
1. A labeling system comprising: a plurality of labels including a
machine readable indicia representing a unique code, each of the
labels further comprising a reflective layer and a substrate, and
wherein the machine readable indicia comprises a light polarizing
material; a labeler for applying the labels to each of a plurality
of articles whereby articles are uniquely identified with one of
the codes; and a computer including a database representing the
plurality of articles, and wherein the unique code for each of the
labeled articles is stored.
2. The system of claim 1 further comprising a media applicator for
applying a light polarizing material in a machine readable format
to the substrate.
3. The system of claim 2 wherein the media applicator is a printer
and the light polarizing material is a dichroic ink.
4. The system of claim 1 wherein the machine readable indicia is a
bar code.
5. The system of claim 4 wherein the bar code is a post net
code.
6. The system of claim 1 wherein the label is oriented polymer
film.
7. The system of claim 6 wherein the film is transparent.
8. The system of claim 3 wherein the dichroic ink is transparent to
visible light and forms a polarizing filter for non-visible light
in one of the UV and IR wavelengths.
9. The system of claim 8 wherein the reflective layer is formed
from a material that is transparent to light in the visible
spectrum and reflects light in one of the non-visible UV and IR
spectrums.
10. A labeling system for applying a machine readable code to a
plurality of mail pieces comprising: means for storing data
corresponding to a plurality of mail pieces, the data comprising
destination information for each of the mail pieces; means for
imprinting a code corresponding to the destination information for
the plurality of mail pieces on a plurality of labels, the code
comprising a light polarizing material; and means for applying the
labels to the mail pieces.
11. The system of claim 10 further comprising means for applying a
light reflective layer to the labels.
12. The system of claim 10 further comprising means for feeding the
mail pieces in a singulated stream to the means for applying the
labels to the mail pieces.
13. The system of claim 12 further comprising means for determining
the position of each of the mail pieces relative to adjacent mail
pieces.
14. The system of claim 14 further comprising means for stacking
the mail pieces.
15. The system of claim 10 wherein the code comprises a bar
code.
16. The system of claim 16 wherein the bar code comprises a post
net code.
17. A system for applying a machine readable destination
information to a plurality of mail pieces comprising: means for
storing data corresponding to each of a plurality of mail pieces;
means for applying a reflective layer to each of the mail pieces in
a selected location on the mail piece; and means for printing a
code corresponding to the data stored for each of the plurality of
mail pieces on the reflective layer after the layer has been
applied to the mail piece, the code comprising a light polarizing
material.
18. The system of claim 17 wherein the code comprises destination
information for each of the mail pieces.
19. The system of claim 17 wherein the light polarizing material
comprises a dichroic ink.
20. The system of claim 17 further comprising means for feeding a
singulated stream of mail pieces to the means for applying a
reflective layer.
Description
[0001] This application is a division of U.S. patent application
Ser. No. 10/033,735, filed Dec. 20, 2001 which claims priority
based on U.S. Provisional Patent Application Ser. No. 60/258,986,
filed Dec. 29, 2000.
TECHNICAL FIELD
[0002] The present invention relates to the field of article
identification methods and systems, and particularly to a label,
system and method that provides a means of coding articles for
identification, sorting and processing with minimal visual
impact.
BACKGROUND OF THE INVENTION
[0003] The system and method according to the invention may be
advantageously applied in a variety of contexts where it is desired
to label articles for identification with minimal impact on the
appearance of the articles, for example items that have been
specially wrapped for presentation, articles having critical
information printed on an exterior surface, decorative items and
the like. Another application in which the system and method of the
invention may be advantageously utilized is in connection with mail
piece labeling for automated processing.
[0004] Modem postal services, for example, the U.S. Postal Service,
handle massive volumes of mail pieces on a daily basis.
Consequently, automated handling and sorting equipment is employed
whenever and wherever possible to facilitate the sorting,
processing and distribution of mail pieces. Such systems have been
proven extremely effective in sorting large volume mail flows, but
these systems have limitations. These systems may use either
optical character recognition (OCR) technology to recognize the
addresses or codes placed on the envelopes, or may use relatively
simple scanners to scan a machine readable code such as a bar code
which has been recorded or applied to each mail piece. The OCR/CS
system often includes a printer for printing bar-code formatted ZIP
codes (or similar codes) on envelopes or on labels applied to mail
pieces so that each mail piece might be further sorted at local
stations more efficiently. Typically, the mail pieces are coded and
sorted according to a sort scheme into numerous groups (e.g. a
range of ZIP codes, ZIP code (5 digits), ZIP code (9 digits),
etc.).
[0005] Facilitating the delivery of certain types of mass mailings
is the process of presorting. A substantial percentage of the mail
the USPS delivers on a regular basis consists of mass mailings.
These mass mailings typically consist of advertisements,
promotional materials, solicitations, bills and similar materials.
Such mailings are printed, addressed or labeled in accordance with
a presort scheme to aid in delivery of the mailings and/or
presorted in some cases down to the delivery point. The presort
scheme is normally by destination address and the mailings are
presented to the national postal service accordingly. In many
cases, the presort operation includes labeling or addressing the
mail pieces with bar coded information such as the ZIP plus four
code to facilitate down stream processing. Presort mailing often
includes catalogues, brochures, magazines and similar items.
[0006] Automated processing of presorted flats, such as magazines
and catalogues presents certain mechanical and imaging problems not
encountered in connection with automated processing of letters.
Although in many cases these mail pieces will have a user-applied
postnet bar code, problems are often encountered in locating the
coded region of interest (ROI) on the cover of the flat. These
problems include poor contrast ratios and partial obscuration due
to printed backgrounds, label skew (rotation from horizontal or
vertical alignment), and the large amount of printed information
which often appears on the covers, including text and other bar
codes, which tends to confuse high-speed algorithmic approaches to
ROI finding.
[0007] A solution for a portion of the mail stream is for the
postal service to apply conventional paper labels on which a
conventional bar code is then printed, thus ensuring consistent
placement and, if necessary, the use of visual keys. However, a
large percentage of the volume of flat mail consists of magazines
and catalogues for which this is not a good solution.
[0008] Publishers of magazines, catalogues, brochures and similar
articles intended for mail delivery often spend large sums on the
design, layout and content of the covers of such publications in
order to achieve the desired visual impact on the recipient. High
quality paper, elaborate design, layout and expensive reproduction
techniques escalate the cost of catalogues and brochures that may
be summarily discarded by the recipient. In many instances, the
initial reaction of the recipient to the cover of a catalogue or
similar publication will determine whether the recipient keeps the
catalogue for further examination or immediately discards it as he
or she sorts through that day's mail. If the visual appearance is
degraded or the publisher's message is partially obscured by a
label, the value of the mailing is reduced. Consequently, there is
a great deal of resistance on the part of the distributors of such
catalogues and magazines to any printing or labeling of the
publications cover that might tend to detract from the cover's
appearance and its visual impact on the consumer. Thus, the
publishers and distributors of magazines, catalogues and brochures
intended for mail delivery generally object to labeling of the
cover of these publications with a typical printed stick-on bar
coded label of the type used by postal and delivery services to aid
in processing and sorting mailed items.
[0009] Attempts to use fluorescent inks have met with little
success due to problems with long drying times for such inks,
smearing of the ink and poor contrast ratios with respect to the
underlying substrate. The latter problem is associated with papers
having high fluorescence, i.e., recycled papers.
[0010] Thus there exists a need for a label and system that allows
the use of techniques and processes for automated labeling and
identification of articles designed to convey a distinct visual
impression. This is particularly true of catalogues, magazines,
brochures and similar publications intended for mail delivery where
a system and method that allows information to be coded onto the
publication with minimal visual impact on the cover of the
publication would be highly desirable. The invention addresses this
need with a label and labeling system having a minimal optical
impact and reading system capable of reliably reading these
labels.
SUMMARY OF THE INVENTION
[0011] The invention provides a method for identifying articles
including labeling the articles with a light polarizing material,
the light polarizing material forming a machine readable indicia
including a code for automated identification of the article. The
light polarizing material is applied over a second, reflective
material that reflects light through the light polarizing material
to create or form an image from which the machine readable indicia
may be reproduced. The image is reproduced by splitting, filtering
and transmitting the reflected light to detectors that produce a
plurality of electronic images which are compared by subtracting
pixels.
[0012] In one aspect, the method further includes utilizing a data
base including a plurality of codes to apply a different machine
readable indicia to different ones of the plurality of articles.
Particular articles may be identified in this manner based upon the
machine readable indicia applied to the article which corresponds
to one of the plurality of identification codes.
[0013] In another aspect, a machine readable indicia is formed on a
plurality of labels from a light polarizing material applied over a
reflective material that reflects light through the light
polarizing material that can be filtered to produce a plurality of
images. The machine readable indicia is reproducible by
electronically comparing the images. The labels are applied to
articles thereby enabling automated identification of the
articles.
[0014] In this respect, automated identification of the articles
includes (1) exposing the machine readable indicia to a source of
light, (2) dividing light reflected from the indicia into a
plurality of beams, (3) filtering each of a plurality of the beams
through a polarized filter offset from each of the other filters by
a predetermined angle, (4) generating an electronic image from each
of the filtered beams with a detector, and (5) comparing at least
one of the electronic images to at least one other of the
electronic images to reproduce an image corresponding to the
indicia. In yet another aspect, the light polarizing material and
the reflective material are transparent to visible light to
minimize the visual impact of the label on the article.
[0015] In yet another aspect, a labeling system according to the
invention includes a plurality of labels including a machine
readable indicia representing a unique code formed from a light
polarizing material and wherein each of the labels includes a
reflective layer and a substrate. The system includes a labeler for
applying the labels to each of a plurality of articles whereby
articles are uniquely identified with one of the codes. The codes
are incorporated into database on a computer that represents the
plurality of articles and in which the unique code for each of the
labeled articles is stored. In one aspect the system includes a
media applicator for applying a light polarizing material in a
machine readable format to the substrate. Preferably, the
applicator is a printer and the light polarizing material is a
dichrotic ink.
[0016] In yet another aspect, an automated article sorting system
according to the invention includes a plurality of polarized lenses
for filtering polarized light reflected from a label including
machine readable indicia comprising a polarized material on the
surface of an article conveyed past the lenses. A detector is
provided for each of the lenses to detect reflected light
transmitted through the polarized lens, creating an electronic
image. The detector sends the signal to a computer that compares
the signals from the detectors to reproduce a pattern corresponding
to the machine readable indicia. The computer generates a sorting
signal corresponding to the indicia that is transmitted to a sorter
that sorts the articles based upon the signal received from the
computer.
[0017] In a preferred embodiment, each of the detectors is a
charged coupled array that generates a digitalized electronic image
from reflected light passing through one of the filters. Each of
the digitalized images are compared by the computer on a
pixel-by-pixel basis to at least one other different digitalized
image to reproduce the machine readable indicia.
[0018] The invention is particularly applicable to mail piece
identification and handling. In this regard, the invention provides
a method for identifying a mail piece by applying a machine
readable indicia to the mail piece, the indicia including a
destination or other code and optionally other printed information.
The machine readable indicia is formed from a polarizing material
with a reflective layer provided beneath the polarizing material to
reflect polarized light back through the indicia, the reflected
light comprising a machine detectable pattern including the printed
code and/or other information. The method may also include the
steps of (a) utilizing a data base including destination codes to
apply the machine readable indicia to a plurality of mail pieces
(b) preprinting a plurality of labels with a light polarizing
material utilizing the database, the labels including a reflective
layer for reflecting polarized light and wherein the reflected
light comprises a machine detectable pattern corresponding to an
entry in the data base and thus inferentially to the destination
code of a mail piece.
[0019] In this regard, the labels are exposed to a light source and
the reflected light is separated with a beam splitter into a
plurality of beams. Each of the plurality of beams is directed
through a polarized filter and each filter is rotated with respect
to each of the other filters by a predetermined angle, for example
60.degree.. A detector such as a charged coupled array is used to
generate an electronic image from each of the filtered beams and
the electronic images are then compared to each of the other
electronic images to isolate the image reflected from the indicia.
In mail processing applications, the machine readable indicia may
be a bar code such as Post Net code or a similar code including
destination information for the mail piece. The system may also
utilize materials which function as indicated only in infra-red or
ultra-violet light so that the indicia and/or the substrate may be
transparent to visible light, further reducing the visual impact of
the indicia relative to the cover of the mail piece.
[0020] In yet another aspect, the invention provides a mail
processing system comprising a computer including a database of
destination codes corresponding to a plurality of mail pieces for
delivery to at least some of the destination codes. A media
applicator coupled to the computer utilizes the database for
generating machine readable indicia in the form of a light
polarizing material, including the destination code for each of the
plurality of mail pieces. The media applicator may be a printer
wherein the machine readable indicia is imprinted with a dichroic
ink on a label. The indicia may be also preprinted on labels which
are then applied to the mail pieces with a label applicator.
Alternatively, the label may be applied to the mail piece prior to
printing.
[0021] The invention also provides a mail sorting system including
a plurality of polarized lenses for filtering polarized light
reflected from a machine readable indicia formed from a light
polarizing material. A detector, such as a charge coupled array, is
associated with each of the lenses for detecting reflected light
and generating a signal in response thereto. The signal is an
electronic image of the mail piece using a selected bandwidth of
light as viewed through the associated polarizing filter in the
form of digitized electronic pixels. The signals from the charge
coupled array are transmitted to a computer which compares the
electronic images to detect a pattern corresponding to the machine
readable indicia. In one embodiment, the computer creates three
different images by subtracting the electronic pixels forming each
image from the electronic pixels forming each of the other images.
The clearest differential image may then be selected. Based upon
the image of the indicia produced by the subtraction, the computer
then generates a sorting signal corresponding to the indicia which
is transmitted to a mail sorter where the mail pieces are sorted
based upon the information contained in the indicia, for example,
by destination code.
[0022] These and other advantages and features of the invention
will be readily apparent from the following Detailed Description
and Drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] For a more complete understanding of the features and
advantages of the present invention, reference is now made to the
detailed description of the invention along with the accompanying
figures in which corresponding numerals in the different figures
refer to corresponding parts and in which:
[0024] FIG. 1 is a top view of a mail piece bearing a label in
accordance with the invention including machine readable indicia in
the form of a bar code;
[0025] FIG. 1(a) is a cross section view of the mail piece and
label of FIG. 1 taken along lines a-a of FIG. 1;
[0026] FIG. 2 is a schematic diagram of a system for identifying
mail pieces utilizing one embodiment of a method of the
invention;
[0027] FIG. 3 is a schematic of a system for sorting mail pieces
utilizing the label and method of the invention;
[0028] FIG. 4 is a schematic diagram of an alternate system for
identifying mail pieces according to the invention;
[0029] FIG. 5 is an illustration of a magazine cover bearing a
label of the type of the invention;
[0030] FIGS. 6a-6c illustrate images of the magazine cover formed
from light reflected from the cover and filtered through polarizing
filters;
[0031] FIGS. 7a-7c illustrate images formed by comparing electronic
images corresponding to FIGS. 6a-6c and subtracting pixels of the
images; and
[0032] FIGS. 8-11 illustrate images of the magazine cover as
filtered and compared in which the effect of variations in
parameters are shown.
DETAILED DESCRIPTION OF THE INVENTION
[0033] While the making and using of various embodiments of the
present invention are discussed in detail below, it should be
appreciated that the present invention provides many applicable
inventive concepts which can be embodied in a wide variety of
specific contexts. The specific embodiments discussed herein are
merely illustrative of specific ways to make and use the invention
and do not delimit the scope of the invention. In particular, while
the invention is described in the context of mail piece
identification and processing, it will be appreciated that the
method and system described herein may be utilized in numerous
other applications where it is desired to label items for the
purposed of identification with minimal impact on the appearance of
the article.
[0034] Sunlight and most forms of artificial light are
electromagnetic waves whose electric field vectors vibrate in all
perpendicular planes containing or orthogonal to the vector which
indicates the direction of propagation. When the electric field
vectors of such radiation are restrained to a single plane, the
light is said to be polarized relative to the direction of
propagation and the electric field waves vibrate in the same plane.
Light may be polarized to a certain degree when it is reflected
from a surface such as water or a highway. In this case, light
waves that have electric field vectors parallel to the reflecting
surface are reflected to a greater degree than those with different
orientations. Light may also be polarized through the use of
certain filters. In one aspect, the invention takes advantage of
the properties of light, in particular polarization, to provide a
label and system for coding mail pieces and in particular pieces
such as magazines, catalogues, brochures and similar items with a
machine-readable code in a form that minimizes the visual impact of
the label on the appearance of the cover of the publication.
[0035] Referring now to FIGS. 1 and 1(a) there is illustrated a
portion of a mail piece 10 such as a catalogue or magazine cover
with a label 12 according to the invention applied thereto. In one
embodiment, the label is formed from a non-opaque material such as
a transparent polymer. Preferably, the label is formed from an
oriented film such that a dichroic ink will form a polarized image
on or in the film. "Dichroic" as used herein refers to the
characteristic of differential absorption of incident radiation in
the visual, UV, and IR spectrum depending upon the direction of
vibration of the electromagnetic waves comprising the radiation. A
"Dichroic ink" refers to an ink containing a dye or stain having
molecules that tend to align with the molecules of a substrate,
such as an oriented film, resulting in a substrate that will
selectively absorb differently polarized components of an incident
light beam. Such inks and techniques for applying such inks are
known, for example U.S. Pat. No. 6,013,123 issued Jan. 11, 2000 to
Scarpetti for "Inking Methods and Compositions for Production of
Digitized Stereoscopic Polarizing Images" discusses the use and
application of inks containing a dichroic dye, water and a
humectant. Also, as used herein the term "light" encompasses
radiation in the visible spectrum ("visible light") as well as
non-visible UV and IR radiation.
[0036] As illustrated the label comprises a machine-readable
indicia 14, in this case a bar code printed with a dichroic ink.
Alternatively, the portion 16 of the label 12 excluding bar code 14
may be printed with a dichroic ink, leaving the bar code as an
unpolarized area. Positioned between label 12 and indicia 14 is a
reflective layer 18 which as illustrated is coextensive with
indicia 14 or, alternatively, with the larger surface 16.
[0037] The purpose of reflective layer 18 is to reflect incident
light so as to provide sufficient contrast for the machine readable
indicia 14. The degree of opaqueness of reflective layer 18 is
preferably maintained at a level sufficient to reflect enough light
to contrast bar code 14 for the purpose of scanning as hereinafter
described, while transmitting as much light as possible to minimize
the visual impact of the label. Depending upon the particular
application, reflective layer 18 may be formed from a number of
known materials capable of reflecting light in the spectrum of
interest, including light in the visible spectrum, infrared or near
infrared and ultraviolet. For example, the reflective layer may be
a plastic film including one or more additives that modify the
optical properties of the film such that the desired spectrum is
reflected from the film. In other applications, a metalized layer
formed with known methods of applying an extremely thin layer of
metal to a substrate such as plastic may be used. A metalized layer
would be particularly suitable for labeling gift and decorative
items covered with a metallic foil or where a metallic foil is used
to protect an item from sunlight. In other applications the
reflective layer may be silica or a similar material incorporated
into a plastic film
[0038] In one preferred embodiment, reflective layer 18 is
partially transparent to visible light, thereby minimizing the
visual impact of the label. The term "partially transparent" as
used herein refers to the capability of a material to pass
sufficient visible light to enable normal visual recognition of an
underlying image. Thus, "partially transparent" may encompass
materials allowing differing degrees of light transmission
depending upon the particular application. While a translucent or
partially transparent reflective layer 18 is preferable, it is not
required for all applications. In some applications it may be
desirable for reflective layer 18 to be opaque and colored to match
an underlying surface and/or be coextensive with the entire area of
label 12.
[0039] In one preferred embodiment, label 12 is formed from an
oriented transparent plastic film with a transparent or translucent
reflective layer 18 printed or applied to the label 12. Machine
readable indicia 14 is formed from a dichroic dye which is
preferable fully transparent to visible light and constitutes a
polarizing filter in the UV or IR wavelengths of light. In this
case, the reflective layer 18 is formed from a material that is
transparent to light in the visible spectrum ("visible light")
while reflecting light in the non-visible UV or IR spectrum. In
this embodiment the visual impact of the label 12 upon the overall
appearance of the labeled article is minimized.
[0040] Referring now to FIG. 2, an apparatus 20 for preparing and
applying labels according to the invention includes an applicator
22 which applies a reflective layer 18 (FIGS. 1 and 1a) onto an
oriented film 26 fed from roll 28. In one embodiment, film 26 has
been perforated along lines defining individual labels and an
adhesive coating or layer has been applied to one side of the film
for adhering the labels to an item or article to be labeled. After
reflective layer 18 has been applied to the film, the film is then
conveyed through a printer 30 that applies a bar code or other
machine readable indicia 14 (FIGS. 1 and 1a) representing a unique
numeric or alpha numeric code to the label using a dichroic ink.
One or more heaters 25 may be used to dry or cure the reflective
layer as well as the ink. Heaters 25 may be forced air or radiant
heaters depending upon the particular design and application. After
printing and curing, the preprinted labels are re-wound into a roll
32 on winder 33 for subsequent use.
[0041] Film 26 comprising preprinted labels 34 is fed to a labeling
machine 36 from roll 32 along with a singulated stream of mail
pieces 10. Destination information for each of mail pieces 10 has
been acquired by reference to a mailing list for the mail pieces,
scanning the mail pieces for previously applied destination
information, manual input of destination information or a
combination of thereof and stored on computer 40. The codes
previously applied to labels 34 have also been transferred to and
stored on computer 40. As the mail pieces 10 are fed through
labeling machine 36 a label having a unique code as previously
described is applied to the mail piece and the code is associated
with the record stored in computer 40 for that particular mail
piece. Thus, the mail pieces can subsequently be identified, sorted
and processed using the code imprinted on labels 34 along with the
record of the mail piece stored on computer 40. As will be
appreciated, in this respect the invention may be particularly
advantageous for use by mailers and/or presorters of magazines,
brochures, catalogues and similar items having covers designed to
convey a distinct visual impact.
[0042] Turning now to FIG. 3, a sorting apparatus 41 for scanning
and sorting mail pieces labeled as described above is illustrated.
A stream of singulated mail pieces is fed from feeder 42 to
conveyor 44 for processing in accordance with the invention. The
location of the mail pieces on the conveyor may be monitored with
one or more photocells (not shown) or by other conventional means
so as to produce a signal for transmission to computer 40 for use
in further processing of the mail stream. Additionally, an edger
(not shown) may be incorporated into the apparatus 41 to ensure
proper placement of the mail piece to enable scanning as
hereinafter described.
[0043] Singulated mail pieces 10 pass under light source 46 which
directs a beam 48 of non-polarized visible or invisible, e.g.,
near-infrared light onto the mail piece 10. Depending upon the
reflective nature of the substrate, the illumination is chosen to
be diffuse or beamed. Reflected light 50 from the mail piece 10
travels to camera 52 which includes one or more dividers such as
beam splitters to generate three machine detectable beams 54 which
are each directed to polarized filters 56. The axis of each of
polarized filters 56 is rotated sixty degrees (60.degree.) relative
to the axes of each of the other filters. The filtered beams 58 are
directed to impinge upon a detector 60 such as a charge coupled
array (CCD). Each of the charge coupled arrays generates a
digitized electrical image of the mail piece 10 from the filtered
beam 58 and transmits the electronic image 62 to a computer 64.
[0044] Computer 64 receives the electronic images 62 from each of
the charge coupled arrays and compares the images. In one
embodiment, computer 64 compares the images 62 by subtracting one
image from another on a pixel-by-pixel basis. Ideally, when an
un-polarized image is subtracted from another un-polarized image of
the same subject, the resulting image will be completely black.
Thus, when an unlabeled mail piece passes under the camera or
scanner 52 the resultant electronic images 62 are all identical and
the resulting combined electronic images will be entirely
black.
[0045] However, when a mail piece bearing a label according to the
invention passes under the scanner 52, the image of the polarized
area of the label 12, as observed via filtered beams 58, will
depend upon the alignment of the polarized portion or indicia 14
with respect to the axis of each of the polarized filters 56.
Computer 64 will therefore generate up to three images from the
three electronic images 62 in which the polarized portion of the
label 12 will appear white or nearly white, while the remainder of
the image will be black. Computer 64 may be programmed to select
the better images, combine images or other wise manipulate the
images to create a high-contrast image.
[0046] After computer 64 has subtracted the digitalized images, the
result is an image in which the barcode or indicia 14 will appear
white against a black background. In practice, minor misalignments
and variations due to the application procedure, focusing and
camera element alignment are observed. However, the high contrast
white image against the background of black is sufficient to
overcome such variations for the purpose of reading the indicia.
Once the machine readable indicia 14 has been isolated as set forth
above, the computer 64 may electronically scan or process the
indicia using known techniques and read the printed code 14 for the
particular mail piece 10. Computer 64 then uses this information
and a data base associating this code with a destination to send a
sorting signal or information corresponding to the mail piece to a
down stream conventional mail sorter or sorting equipment 66, where
the mail pieces 10 may be sorted by destination code or other
criteria, with or without mail pieces originating from other
sources, depending upon the particular application.
[0047] Referring now to FIG. 4, there is illustrated an alternate
system 70 for applying labels in accordance with a method of the
invention to a plurality of mail pieces such as magazines,
brochures or catalogues. Feeder 72 feeds a stream of singulated
mail pieces 10 onto conveyor 74. The location of the mail pieces on
the conveyor may be monitored with one or more photocells (not
shown) or by other conventional means so as to produce a signal for
transmission to computer 76 which controls the process. A label
applicator 78 applies a label, for example a piece of oriented
transparent polymer film with a pre-applied adhesive, to each of
the mail pieces 10 as the mail pieces are conveyed though the
system 70. In order to ensure placement of the label in the desired
position, the mail piece may be edged, as is known in the art with
an edger (not shown). As the mail pieces travel down the conveyor
74, a reflective layer 18 (FIGS. 1 and 2) is applied to the label,
by for example, printing the layer 18 onto the label with a first
media applicator 78. As will be appreciated, the reflective layer
18 could have been previously applied to the label film, in which
case, this operation could be eliminated.
[0048] As the mail pieces travel further, a second media applicator
80 applies a machine readable indicia 14 (FIGS. 1 and 2), by, for
example, printing the indicia 14 over the reflective layer 18 with
a dichroic ink. The machine readable indicia may include a
destination code for the particular mail piece or some other code,
symbols, or text to be used in subsequent handling or processing. A
computer 82, including a database 84 controls the operation of the
second media applicator 80, suppling the destination code from
data, for example, a mailing list, stored in database 84. In an
alternative embodiment, second media applicator 80 may comprise a
laser or UV light source, the light source imprinting a polarized
or non-polarized indicia on a pre-sensitized or treated film label.
In the case of a pre-sensitized polarized film, the light source
may depolarize an area of the label corresponding to a machine
readable indicia. In the alternative, the pre-treatment of the film
may allow the laser to selectively polarize areas of the label
corresponding to a desired indicia.
[0049] Following application of a machine readable indicia 14 upon
the label 12, the mail pieces 10 are transported for further
processing, for example stacking and bundling with stacker 66. The
labeled mail pieces may then be transported to a postal service
sorting system which may use a scanning apparatus of the type
described herein to readily sort the mail pieces 10 for delivery
based upon the destination code printed on the label.
[0050] As will be appreciated, numerous variations and permutations
of the above-described process may prove advantageous. In the case
where the address of the recipient is printed upon the mail piece,
and an optical character scanner (OCR) may be used to read the
information which could then be transmitted to the computer 82 for
labeling purposes. It is also anticipated that the reflective layer
could be pre-applied to the label film, or during production of the
film.
[0051] As will be appreciated, variations on the above system may
be readily discerned. For example while the system is described as
having a light divider that directs beams to a plurality of
filters, multiple cameras may be used with different filters and
filter configurations to produce the same result. Similarly
purpose-built electronics and/or multiple computers or
microprocessors may be employed to perform the various functions
described above. These and other combinations and permutations are
within the scope of the invention.
[0052] In order to fully illustrate the principles of the
invention, reference is now made to FIGS. 5-11. Turning first to
FIG. 5 there is shown the cover of a popular magazine as would be
perceived by the human eye, including label 12. FIGS. 6a, 6b and 6c
correspond to the images as the images are captured by each of
three 2048 pixel (from left to right) charge coupled arrays. As
shown, the images are nearly identical except that the image of the
bar code varies in brightness between the images. FIGS. 7a, 7b and
7c are the result of digitally subtracting each of the images of
FIGS. 6a, 6b and 6c from each other, i.e., 6a-6b, 6a-6c and 6b-6c.
In each of the images presented in FIGS. 7a-7c, the only non-black
portion of the image is the bar code and the brightness of the code
in each of the images is a function of the brightness of the images
in the particular pair of subtracted images. In operation, it is
anticipated that all three images will be generated with one being
selected for reading based upon its relative brightness.
[0053] FIGS. 8-11 illustrate anticipated deviations from the ideal.
FIG. 8 shows the effect of a one-pixel shift horizontally combined
with a one-pixel shift vertically to simulate the translational
misalignment of two charge coupled arrays. FIG. 9 illustrates the
anticipated effect of a small rotational misalignment with the arc
of the misalignment corresponding to a shift of one pixel at a
corner of the image. FIG. 10 shows the anticipated effect of a
possible scaling error resulting from one of the charged coupled
arrays observing a slightly larger image, i.e., 2 pixels along the
horizontal axis, than observed by the other charge coupled arrays.
FIG. 11 illustrates the image resulting from a combination of the
misalignments shown in FIGS. 8-10. As illustrated, while some of
the background is not entirely black, the degree of contrast is
still sufficient to enable scanning and reading the label. Thus,
the label and system of the invention are capable of tolerating
minor variations that may be encountered in manufacturing,
imprinting and scanning operations without affecting the operation
of the system.
[0054] While this invention has been described with reference to
illustrative embodiments, this description is not intended to be
construed in a limiting sense. Various modifications and
combinations of the illustrative embodiments, as well as other
embodiments of the invention, will be apparent to persons skilled
in the art upon reference to the description. It is, therefore,
intended that the appended claims encompass any such modifications
or embodiments.
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