Note: Descriptions are shown in the official language in which they were submitted.
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MAIL CODE EVALUATION SYSTEM
BACKGROUND OF THE INVENTION
The present invention relates to evaluating barcodes,
and more particularly relates to the detection and reporting
of a defective barcode on a mail piece.
Throughout the history of the mail delivery, there has
been a gradual evolution whereby the post office encourages
mailers to prepare their mail in such a way as to reduce the
effort required on the part of the post office for
processing such mail. As an inducement to the mailer to
prepare the mail in such a way so as to bring about faster
mail delivery, the post office offers a postage discount to
mailers for such items as presorted mail and printing of ZIP
codes.
Recently, the United States Postal Service CUSPS) has
adopted new ZIP codes which contain more detailed
destination information than the original five-digit ZIP
code. One new form of ZIP code ("ZIP + 4") contains an
additional four digit extension which generally identifies
an address within a side of residential block. A further
enhanced ZIP code system utilizes 11-digit ZIP codes to
specify a point of delivery.
Discounts are also given when the mail is marked with a
barcode corresponding to the ZIP code. Barcoding enables
mail sorting machines to more rapidly sort and route mail
from a mailer to a receiver. The Postal Numeric Encoding
Technique (POSTNET) was developed by the USPS to provide an
optimized barcode system for encoding ZIP code information
on mail.
One problem that arises in determining whether a mailer
is deserving of a discount is the objective evaluation of
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barcode quality. One focus of this evaluation should be
readability of the mail piece barcode. When a barcode
cannot be effectively read or scanned by automation
equipment, laborious manual handling of the mail piece
typically results. Another troublesome barcoding defect is
a barcode that does not correspond to the designated
address. Such inaccurately barcoded mail pieces may be
misdelivered and frequently result in additional manual
handling. In addition to a more objective identification of
barcode defects, a concise method of visually reporting and
summarizing defects is needed to determine an effective
corrective action. Also, such reporting is needed to
support the refusal to award a discount to a mailer because
of poor barcode quality.
I5 Thus, there is a need for an evaluation system to
efficiently detect mail piece barcode defects, including
barcode readability and accuracy determinations, with a
minimum of laborious operator activity. Preferably, this
system should be capable of classifying and reporting a
summary of classified defects to facilitate corrective
action. Also, it would be preferred for this system to
reduce the need for subjective identification and
categorization of barcode defects by an operator.
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SUMMARY OF THE INVENTION
Accordingly, in one aspect of the present invention
there is provided a mail barcode evaluation method,
comprising the steps of:
(1) feeding a mail piece with a barcode to an imaging
device for evaluation;
(2) generating an image of the barcode with the imaging
device;
(3) evaluating the image generated in step (2) with a
processor to identify a first barcode defect; and
(4) visually presenting a first marker to indicate location
of the first barcode defect along the barcode.
According to another aspect of the present invention
there is provided a method of evaluating a mail piece
having a barcode and an address block, comprising the steps
of
(1) feeding a mail piece with a barcode to an imaging
device for evaluation;
(2) decoding the barcode to correspondingly provide a
decoded address;
(3) generating an image of at least a portion of an address
block appearing on the mail piece with a processor; and
(4) comparing the image of step (3) with the decoded
address of step (2) to determine if the barcode is
defective.
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According to yet another aspect of the present
invention there is provided a system for evaluating
barcoded mail, comprising:
an imaging device configured to provide an image
signal corresponding to an image of a barcode from a mail
piece;
a transport device configured to selectively deliver
the mail piece to said imaging device for evaluation;
an output device for providing evaluation results;
a processor receiving said image signal, said
processor being configured to compare said image signal to
barcode requirements data to detect a barcode defect, said
processor being configured to provide an output signal to
said output device if said barcode defect is defected; and
wherein said output device responds to said output
signal to provide a visual barcode defect marker, said
marker indicating said barcode defect location.
According to yet another aspect of the present
invention there is provided a system for evaluating
barcoded mail, comprising:
an imaging device configured to provide an image
signal corresponding to a barcode and at least a portion of
a destination address of a mail piece;
an output device for providing evaluation results;
a processor receiving said image signal, said
processor being configured to decode said barcode from said
image signal to generate a decoded address signal
corresponding to an address decoded from the barcode, said
processor being configured to provide an output signal to
said output device in accordance with said decoded address
signal and image signal; and
wherein said output device responds to said output
signal to provide a decoded address image corresponding to
said decoded address signal and a mail piece image
corresponding to said image signal, said decoded address
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image and said mail piece image being provided for visual
comparison.
According to still yet another aspect of the present
invention there is provided a system for evaluating
barcoded mail, comprising:
an imaging device configured to provide an image
signal corresponding to a barcode and at least a portion of
a destination address of a mail piece;
an output device for providing evaluation results;
a processor receiving said image signal, said
processor being configured to decode said barcode from said
image signal to generate a decoded address signal
corresponding to an address decoded from the barcode, said
processor being configured to compare said decoded address
signal to at least a portion of said image signal to detect
a barcode accuracy defect, and said processor being
configured to provide an output signal to said output
device if a barcode accuracy defect is detected; and
wherein said output device responds to said output
signal to indicate the barcode accuracy defect.
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According to still yet another aspect of the present
invention there is provided a mail barcode evaluation
method, comprising the steps of:
(1) feeding a mail piece to an imaging device for
evaluation;
(2) generating an image of a barcode from the mail piece
with the imaging device;
(3) evaluating the image with a processor to identify a
barcode defect;
(4) determining a defect state corresponding to the barcode
defect identified in step (3), the defect state being
selected from among at least four defect states by the
processor, ana
(5) printing a report with an image of the barcode and a
marker, the marker indicating the defect state determined
in step (4).
Accordingly, it is one object of an aspect of the
present invention to provide a method and system to
evaluate mail piece barcode defects.
Another object of an aspect of the present invention is
to provide a method and system for categorizing and
reporting mail piece barcode defects.
Further objects, features, and advantages of the
present invention shall become apparent from the detailed
drawings and descriptions provided herein.
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BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top view of an evaluation station
of one preferred embodiment of the present invention;
FIG. 2A is a flow diagram of one preferred process of
the present invention performed with the embodiment shown in
FIG. 1;
FIG. 2B is a continuation of the flow diagram of FIG. 2A;
FIG. 3 is a depiction of one example of a mail piece
face processed in accordance with the process of FIGS. 2A &
2B;
FIG. 4 is a depicition of one example of a visual
display in accordance with the process of FIGS. 2A & 2B;
FIG. 5 is a depiction of one example of a report
provided in accordance with the process of FIGS. 2A & 2B;
FIG. 6 is a top partial view of a feeder system of the
present invention;
FIG. 7 is a top partial view of the feeder system of
FIG. 6 in another position; and
FIG. 8 is an elevational view of a portion of the feeder
system shown in FIGS. 6 and 7.
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DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the
principles of the invention, reference will now be made to
the embodiment illustrated in the drawings and specific
language will be used to describe the same. It will
nevertheless be understood that no limitation of the scope
of the invention is thereby intended. Any alterations and
further modifications in the illustrated device, and any
further applications of the principles of the invention as
described herein being contemplated as would normally occur
to one skilled in the art to which the invention relates.
FIG. 1 schematically depicts a mail piece barcode
evaluation station 10 of the present invention. As used
herein, "mail" or "mail piece" includes an item entrusted
with a postal service or private delivery organization for
transport to a designated destination. Station 10 has mail
handler 20 coupled to processor 50 having various
input/output devices, including keyboard/mouse 64 for
interfacing with operator 70.
Mail handler 20 has bed 21 which defines feed bin 22 for
holding mail pieces in a mail row 24 for evaluation.
Transport system 25 selectively moves mail a piece at a time
from feed bin 22. Transport system 25 includes feeder 26,
transport path 28 and transport controller 30. Feeder 26
selectively feeds mail from mail row 24 to transport path
28. Transport of a mail piece, such as mail piece 34 shown
in transport path 28, is controlled by transport controller
30. In FIG. 1, the direction of travel provided by
transport system 25 is generally from left to right,
although in other embodiments, the direction of travel path
of mail pieces may differ. Transport path 28 and transport
controller 30 are of a conventional type commonly used in
mail handling systems. Transport system 25 may include
pinch rollers or belt conveyors.
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Imaging device 32 is configured to selectively provide a
signal corresponding to an image of an item viewed adjacent
platten 36. Mail piece 34 is shown in this imaging
position. Preferably, imaging device 32 is a line scan
camera which generates an electric signal corresponding to a
scanned image. Alternatively, imaging device 32 may be an
area camera, an array of optical sensors, or such other
imaging device as would occur to one skilled in the art.
After traveling by imaging device 32, transport system
25 provides for the passage of a mail piece to print head
38. Print head 38 selectively marks mail in transport path
28. Preferably, print head 38 is of the ink jet variety.
Alternatively, another type of marking device could be used.
Mail exits transport path 28 into collection bin 42.
Z5 Collection bin 42 holds mail row 44 after processing along
transport path 28. Stacker 46 assembles and maintains
evaluated mail row 44 and is of a known type.
Alternatively, bins 22, 42 and stacker 46 may be considered
components of transport system 25. Instead of collection
bin 42, other embodiments may transport mail to a tray or
other device after processing in mail handler 20.
Processor 50 is used to coordinate and control various
operations of station 10. Processor 50 includes barcode
requirements data 52 which provides information pertinent to
acceptability of a barcode. Preferably, requirements data
52 includes parameters to comparatively identify a variety
of barcode defect states and evaluate severity of a given
type of defect. More preferably, defect states and
associated severity levels are used to either fail the
barcode as unreadable or provide a warning about
readability. It is preferred that at least four defect
states are detectable. It is more preferred that at least
10 defect states are detectable. It is most preferred that
at least 16 defect states are detectable.
Furthermore, processor 50 includes a Look-Up Table (LUT)
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54 configured to determine at least a portion of an address
corresponding to a proper mail piece barcode. Preferably,
LUT 54 is entered with data obtained from scanning a bar
code to produce at least a portion of a corresponding
multicharacter address. This decoded address may be further
processed to verify accuracy of the bar code.
Requirements data 52 and LUT 54 may reside in a store
associated with processor 50. This store may be fixed or
removable. Preferably, the store is a memory device of the
electronic (e. g. solid state), magnetic, or optical variety,
which may be readily updated as bar code standards or
address/barcode tables change. In one embodiment, data 52,
LUT 54, or both are provided from a remote store or other
source via a communication device for processing. In this
embodiment, the source and communication device are
considered to be a portion of processor 50 for the purposes
of the present invention.
Processor 50 may be an electronic circuit comprised of
one or more components. Similarly, processor 50 may be
comprised of digital circuitry, analog circuitry, or both.
Also, processor 50 may be programmable, an integrated state
machine, or a combination thereof. Preferably, processor 50
is a ruggedized industrial grade programmable personal
computer with customized circuitry and software to interface
with various components of station 10. This preferred
configuration may include communication interfaces such as
modem or network links, and subsystems to accommodate
removable media, such as compact disks (CDs) or floppy
disks.
Processor 50 controls selected operations performed by
mail handler 20 through mail handler interface 56. Mail
handler interface 56 has operative links to feeder 26,
transport controller 30, imaging device 32, and print head
38. Processor 50 is also coupled to a number of
Input/output (I/O) devices common to personal computers via
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I/0 interface 58. I/O devices coupled to processor 50 via
I/0 interface 58 include Cathode Ray Tube (CRT) display 60,
printer 62, speaker/microphone 66, and keyboard/mouse 64.
Preferably, CRT display 60 is of the conventional color
variety available for personal computer applications.
Alternatively, a liquid crystal display or other visual
display responsive to processor 60 may be used. Printer 62
is preferably of the laser variety, but could be of another
type as would occur to one skilled in the art. Speaker and
l0 microphone 66 preferably include interface circuitry to
facilitate delivery and reception of audible commands by
processor 50; however, in other embodiments
speaker/microphone 66 may be absent. The keyboard and mouse
of keyboard/mouse 64 may be separate or combined units of a
conventional variety. In alternative embodiments, only a
mouse or keyboard is employed. In fact, in an embodiment
having an audible command system via speaker/microphone 66,,
keyboard/mouse 64 may be absent.
FIGS. 2A & 2B illustrates process 500 of the present
invention performed with the preferred embodiment depicted
in FIG. 1. Process 500 starts with power-up at step 502.
Next, mail is loaded in feed bin 22 in step 504. In step
506, operator 70 enters the name of the customer for whom
the mail piece barcode evaluation is performed using
keyboard/mouse 64 or speaker/microphone 66. Step 506 also
includes the entry of the sample size of barcoded mail
pieces for the bar code evaluation. Transport system 25
begins to operate in step 508.
Step 510 initiates singulation and feeding of a mail
Piece from mail row 24 with feeder 26. Also, transport
system 30 delivers the mail piece along transport path 28 to
platten 36 for scanning by imaging device 32. After
imaging, the mail piece is moved to print head 38 and a
unique number ("N") or other identifying mark is printed on
the mail piece in step 512. The mail piece is then routed
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to collection bin 42 by transport system 25.
Referring additionally to FIG. 3, processed mail piece
340 is shown. Face 341 of mail piece 340 includes postage
zone 342, return address zone 344, and address block 350.
Address block 350 includes an alphanumeric destination
address 352 and a barcode 354. Face 341 also includes an
identification number "N" at zone 346. Identification
number "N" may be supplied by print head 38 to identify the
mail piece in relation to the evaluation sequence. Step 512
corresponds to this marking and also includes the routing of
mail pieces to collection bin 42 after evaluation.
In step 514, processor 50 receives a signal from imaging
device 32 corresponding to the image of the face of a mail
piece. Referring to mail piece 340 by way of example, in
step 514, processor 50 receives a signal from imaging device
32 corresponding to an image of at least a portion of face
341 of mail piece 340. Processor 50 locates address block
350 and discriminates between images corresponding to
destination address 352 and the barcode 354. U.S. Patent
Nos. 5,431,288 to Nishijima et al., 5,387,783 to Mihm et
al., 5,249,687 to Rosenbaum et al., 5,073,954 to Van Tyne et
al., and 4,632,252 to Haruki et al. generally disclose
techniques to recognize addresses and barcodes in connection
with image processing of mail.
Processor 50 is configured to evaluate barcode
readability by comparing the barcode image to barcode
requirements data 52. If a defect has been identified as
queried in conditional 516, then preferably processor 50
categorizes the defect using requirements data 52 in step
518. It is more preferred that processor 50 determine
defect severity to further classify defects as either
failures or warnings. It is most preferred that processor
50 recognize and identify multiple defects and associated
severity levels. The defect data and associated barcode
image are stored for later reporting.
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After evaluating for readability defects, control flows
to conditional 520 to determine whether the piece has been
selected to perform an accuracy check. Preferably, the
accuracy check is performed on a randomly selected subset of
the sample size entered in step 506. If a mail piece is
designated for an accuracy check, then the corresponding
address block image is stored fox later evaluation in step
522.
Conditional 524 determines whether the sample size
entered in step 506 has been reached. If the sample is not
complete, control returns to step 504 to feed the next piece
for evaluation. If the sample is complete, control flows to
step 526 (See FIG. 2B).
Referring to FIG. 4, a sample screen 602 using display
60 is illustrated which presents results corresponding to
the performance of the next three steps, 526, 528, and 530
of process 500. Screen 602 includes a banner 604 to
indicate the nature of the operation. Specifically, the
accuracy check for a selected piece "N" is indicated. In
step 526, the imaged barcode of a stored accuracy check
piece is accessed and decoded to determine at least a
portion of an address corresponding to the barcode.
Preferably, processor 50 performs this operation with LUT 54
using data corresponding to the scanned bar code for entry.
This decoded address is then sent as a visual image to
display 60. FIG. 4 shows decoded address 654 in output
block 606. Decoded address 654 is one example of an output
which corresponds to 526. Preferably, step 526 provides a
decoded address in a discrete character-based text format
such as ASCII, although other formats as would occur to
those skilled in the art are also contemplated.
In step 528, the imaged address block is displayed on
the screen of display 60 next to the decoded address
generated in step 526. FIG. 4 presents one example of the
output of step 528 as imaged address block 650 in output
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block 608. Imaged address block 650 is for the same mail
piece having decoded address 654. In one embodiment, imaged
address block 650 is presented in a graphical format which
readily accommodates hand-written addressing. In
alternative embodiments, imaged address block 650 may be
converted into a character format or presented as a mixed
character and graphical presentation. U.S. Patent Nos.
5,475,603 to Korowotny, 5,431,288 to Nishijima et al.,
5,422,821 to Allen et al., 5,249,687 to Rosenbaum et al.,
and 5,031,223 to Rosenbaum et al. provide various Optical
Character Reader (OCR) mail piece processing methods which
may be adapted to convert an imaged address block into at
least a partial character format.
In step 530, the operator 70 is prompted to indicate
~5 whether on-screen images of the decoded address and the
destination address appearing on the face of the mail piece
match. If there is no match, then the barcode is usually
inaccurate. This step avoids the laborious task of culling
through evaluated mail pieces to verify barcode accuracy of
a sampled sub-set. Output block 6I0 of screen 602 provides
one example of such a prompt with regard to the comparison
of decoded address 654 and imaged address block 650.
Operator 70 may input this data by using mouse cursor 612
with the "YES" or "NO" button. Alternatively, a keyboard
entry or an audible command may be used to input the
operator response.
Conditional 532 queries whether a failed comparison (no
match) is indicated. If the comparison fails, step 534
provides for storage of the decoded address and
corresponding address block image of the mail piece for
later reporting in step 538. Control then flows to
conditional 536 to determine if additional accuracy checks
need to be performed for other mail pieces. If further
checks remain, then control loops back to step 526.
Otherwise, a report is printed with printer 62 in step 538.
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In step 540, the system is powered down and process 500
stops.
Notably, the steps and conditionals of process 500 may
be configured to generally correspond to various signals or
variables associated with station 10. For example, in the
case of processor 50, various output signals may result in
connection with the generation of defect reports and other
signals correspond to data and operations within processor
50. Also, various devices of station 10 exchange signals
with processor 50 which may correspond to one or more
elements of process 500.
In one alternative embodiment, evaluation by processor
50 of barcode accuracy includes the utilization of OCR.
Specifically, in this embodiment, processor 50 determines
the characters of at least a portion of the destination
address on the face of a mail piece from its image. This
discriminated destination address is then compared by
processor 50 to the decoded address from the mail piece
barcode. This process may avoid the need to involve the
operator in the accuracy check determination. In a
variation of this embodiment, the operator is prompted to
perform barcode accuracy comparisons only when the OCR
process cannot be performed within a predetermined amount of
time. For example, because some OCR processes perform
poorly for handwritten destination addresses, these
addresses may be candidates for selective operator
comparison.
Preferably, a report is provided by station 10 which
includes a visual reproduction of the decoded address and
address block image appearing on each mail piece which fails
the accuracy check. Also, it is preferred that a copy of
unreadable barcodes with defect category indicators be
printed for each failed barcode. In an alternative
embodiment, barcode warnings are also supplied. In another
embodiment, the sensitivity of the barcode defect detection
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is adjustable and may be tailored to examine barcode process
trends for quality control purposes.
Referring to FIG. 5, one type of barcode readability
report 700 is depicted. This report includes a banner 702
indicating the customer and the readability rate. In this
case two failed barcodes, 710 and 720 are depicted. "Piece
23" and "Piece 99" correspond to the piece ID numbers "N"
placed on the mail pieces by print head 38, for barcodes
710, 720, respectively. In accordance with indicator key
730-, defect markers include lower case letters to indicate
warnings and upper case letters indicate a failure. Also,
in this example, 5 warning defects have been selected to
result in a failure. Each block 714, 724 of report 700
provides lower case characters "b" to indicate the location
of offending individual bars of each corresponding barcode
710, 720. Specifically, these characters are aligned
beneath bars which are believed to be too short (see
indicator key 730). Also, "B" is shown beneath the fifth
"b" of each blcok 714, 724 to indicate a failure due to an
excess number of warnings. In addition, indicators 712, 722
correspond to other defect states resulting in failure that
are generally not location specific (see key 730). Two
markers are shown in indicator 722 corresponding to the
detection of two defect states for piece 99 which are not
location specific. Various other report indicator keys 730
and markers are contemplated as would occur to one skilled
in the art.
Report 700 may be varied in length and number of pages
to correspond to the number of defective barcodes detected.
In one embodiment, report 700 is prepared for presentation
on display 60. Other visual display media for reporting
barcode defects with corresponding images or facsimiles are
contemplated as would occur to one skilled in the art.
Furthermore, the storage and transfer of barcode defect data
and reports on non-visual electronic, magnetic, or optical
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media in corresponding formats is contemplated. Notably. in
one embodiment, the imaging information is stored on a
- portable disk for subsequent downloading and evaluation by
~ processor 50 without otherwise coupling to imaging device
32. Also, processor 50 may be used to generate and report
various statistical information associated with barcode
evaluation.
In another embodiment, defects may be indicated by
printing an appropriate indicator on the corresponding
defective mail piece with print head 38 after evaluation.
In one version of this embodiment, a deflector under the
control of processor SO is included between transport path
28 and stacker 46 to segregate failed mail pieces into a
separate reject bin for later review (not shown). Because
defect state and location markers are printed directly on
the mail piece, the printing of a reproduction of the
barcode with appropriate markers may not be necessary for
this embodiment.
Referring to FIGS. 6-8, feeder system 100 of the present
invention is next described. Feeder system 100 may be used
in lieu of feeder 26 depicted in FIG. 1.
Feeder system 100 selectively singulates and feeds mail
pieces from mail row 101 to transport system 282 in response
to a signal S received by feeder control logic 110. Feeder
system 100 includes a magazine 240 with an input section 246
and bed 242. Bed 242 defines a number of recesses 251a,
251b, 251c in which corresponding chains 252a, 252b, 252c
are located. Chains 252a, 252b, 252c are selectively driven
in the direction of arrow F by magazine drive 253 in
response to a magazine control signal from feeder control
logic 110. Push plate 248 is slideably mounted to guide bar
250 and includes teeth (net shown) to selectively engage
chains 252a, 252b. 252c for travel therewith. Plate 248 is
configured to rotate about guide bar 250 to selectively
disengage chains 252a, 252b, 2S2c to adjust for different
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size mail rows. Preferably, plate 248 is positioned to urge
mail row 101 in the direction of arrow F with a
predetermined amount of pressure.
Feeder system 100 also includes endless belt system 120
with upper belt 122, middle belt 124, and lower belt 126.
Together, belts 122, 124, 126 define a moving contact belt
face 128 to frictionally engage a mail piece for transport.
Belts 122, 124, 126 are configured to move by rotating
spindles 130, 132 by a motor (not shown). Also, endless
belt assembly 120 includes idler 134. In other embodiments,
idler 134 may be absent. Generally, belts 122, 124, 126 are
rotated to move in the direction indicated by arrow B shown
in FIG. 6.
Feed system 100 also has a gate assembly 140 with arms
142a, 142b, 142c, 142d (collectively designated arms 142)
mounted to leg 141 and cross brace 143. Cross brace 143 and
leg 141 are generally positioned at opposing ends of arms
142. Gate assembly 140 also has a contact plate 144 mounted
to arms 142. Arms 142 are configured to interleave with
belts 122, 124, 126 as shown in FIG. 8 and pivot about axis
P generally coincident with leg 141.
Gate assembly 140 also has solenoid 146 with plunger 147
to selectively pivot arms 142 about axis P and along path
R. Solenoid 146 is operatively coupled to feeder control
logic 110 so that is selectively responds to a gate control
signal from logic 110 to extend or retract plunger 147
(compare FIG. 6 and 7). Preferably, solenoid 146 is
activated to extend plunger 147 in response to a discrete
gate control signal. Besides solenoid 146, other actuators
may be used such as a selectively driven motor connected to
a rotating cam device. Also, a controllably rotated arm
with rollers to contact plate 144 may alternatively be
employed. In addition, a bell crank or crank arm may be
used in conjunction with a translational or rotational
device to provide an actuator suitable for gate assembly 140.
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A pressure sensor 148 is associated with plate 144 to
determine the amount of pressure exerted on arms 142 by mail
row 101. Sensor 148 sends a corresponding pressure signal
to feeder control logic 110. Preferably, pressure sensor
148 is of the microswitch variety providing a discrete
digital signal corresponding to the existence of at least a
predetermined level of pressure.
Roller 150 of feeder system 100 turns in a direction
opposite the movement of belt contact face 128. Roller 150
is spaced apart from endless belt assembly 120 and gate
assembly 140 to define a feed gap 152. Feed gap 152 is
aligned with feed path 154 and nip 166 of pinch roller
assembly 160.
Pinch assembly roller 160 includes pinch rollers 162,
164 to transport a mail piece to transport system 282.
Pinch roller assembly 160 also includes a sensor 168 to
provide a detection signal corresponding to the presence of
a mail piece as it enters nip 166. Sensor 168 may be of an
optical variety which sends a discrete signal corresponding
to a mail piece blocking a beam of light.
Feeder system 100 operation is next discussed. Endless
belt assembly 120, roller 150, and pinch roller assembly 160
are generally in free-running rotational motion, being
driven by an associated driving motor (not shown) in a
conventional manner. The direction of motion of various
components is indicated by arrows superimposed thereon.
As shown in FIG. 6, gate assembly 140 has a hold
position which presses against mail row 101 and away from
endless belt assembly 120. In the hold position, plunger
147 of solenoid 146 is extended and bears against contact
plate 144 to hold arms 142 against mail row 101. If push
plate 248 is not positioned to provide adequate pressure of
mail row 101 against gate assembly 140, then pressure sensor
148 sends the pressure signal to feeder control logic 110.
Feeder control logic 110 responds by sending the magazine
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control signal to magazine drive 253 to correspondingly
drive chains 252a, 252b, 252c to move push plate 248 along
path F toward gate assembly 140 and restore adequate
pressure. Once adequate pressure is obtained, the control
logic 110 terminates activation of magazine drive 253.
In response to a feed signal S, feed control logic 110
sends the gate control signal to solenoid 146 to retract
plunger 147. Upon retraction, gate assembly 140 changes
position to selectively feed a leading mail piece 154a from
mail row 101. Specifically, arms 142 pivot behind contact
face 128 to a feed position as shown in FIG. 7.
In the feed position, face 128 contacts lead mail piece
154a to frictionally transport it through feed gap 152 along
feed path 154 to nip 166 of pinch roller assembly 160. As
lead mail piece moves along feed path 154, roller 150
generally discourages the feeding of additional mail pieces
at the same time. Roller 150 turns in the same rotational
direction as endless belt assembly 120 (e.g. clockwise or
counterclockwise), but the surfaces of roller 150 and belts
122, 124, 126 approach one another moving in opposite
directions as the superimposed arrows indicate. The
coefficient of friction of the surface of roller 150 is
generally less than the surface of belts 122, 124, 126 so
that a mail piece in contact with face 128 tends to move
along feed path 154 even if it also contacts roller 150.
However, because the coefficient of friction between two
adjacent letters is generally less than the coefficient of
friction with contact face 128 or roller 150, multiple
pieces fed into gap 152 at the same time typically result in
the letter closest to belt contact face 128 being
transported along feed path 154 with the remaining piece or
pieces being transported in the opposite direction back to
magazine 240 by roller 150.
As the edge of a leading mail piece 154a is detected by
sensor 168 of pinch roller assembly 160, the detection
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signal is sent to feeder control logic 110. In response,
feeder control Iogic extends plunger 147 to return gate
assembly 140 to the hold position to await another feed
' signal S to feeder control logic 110. Notably, as mail
S pieces are singulated and fed by feeder system 100, mail row
101 decreases in size and the pressure on gate assembly 140
correspondingly drops. As a result, pressure sensor 148
periodically sends a pressure signal to feeder control logic
110 to drive chains 252a, 252b, 252c via drive 253 to
reestablish the required pressure for the functioning of
feeder system I00. Notably, when all mail has been fed,
sensor 168 will fail to detect an edge of a mail piece.
Such repeated failures could be used to report the
possibility of an empty input section 246 or another feeder
Problem as may be appropriate.
Feeder assembly 100 provides a cost effective means for
selectively feeding mail in a barcoding application.
However, feeder assembly 100 may also be used to enhance a
variety of mail handling systems. Preferably, feeder
control logic 110 comprises discrete logic components to
provide a reliable and cost effective controller. Other
controllers suitable to provide feeder control logic 110 are
of the microprocessor variety. In an embodiment of station
10 using feeder system 100 in lieu of feeder 26, processor
50 may be adapted to include feeder control logic 110 using
methods known to those skilled in the art.
While the invention has been illustrated and described
in detail in the drawings and foregoing description, the
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same is to be considered as illustrative and not restrictive
in character, it being understood that only the preferred
embodiment has been shown and described and that all changes
and modifications that come within the spirit of the
invention are desired to be protected.
