Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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MAGNETIC INK CALIBRATION DOCUMENT : :
FIELD OF THE INVENTION i ~ ~:
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The present invention relates to a calibration
document having an accurately assigned magnetic ink ;~
intensity value.
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BACKGROUND OF THE INVENTION -~
Certain documents and in particular negotiable
documents are printed with magnetic ink, ribbon or toner
15 for machinery reading purposes. Negotiable documents are -~
printed with what is known as the E-13s MICR font which
includes a series of MICR (magnetic ink character
recognition) symbols or characters. The magnetic ink
printing of these characters provide an electronically
readable signal to a machine for reading the document.
However, if the signaI strength is either~too high or too
low, the document cannot be read and is re~ected from the ;~
machine reader. This presents serious problems to cheque
printers who must therefore care~fully scrutinize magnetic '
25~ ink levels on the documents that they have printed.
In the past,~secondary paper reference documents
have~been used as a means to calibrate test equipment for
asse~ssing whether or not a magnetic ink character
recognition document, i.e.;a MICR document~ has an
appropriate level of mag;netic ink to be readable by a
machine reader.~ In particular,~ many years ago, the sank
~Administration Institute in Chicago produced what were
known as secondary reference documents having MICR ~encoded
characters with an optimum signal strength for machine
reading purposes. These~documents, which were made from
primary reference documents, had a known magnetic ink
signal strength value, and were fed through test equipment ;-'
which was then calibrated based on the secondary reference
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document. Over the decades, further secondary reference
documents have been printed off of these primary reference
documents and as will be appreciated, through aging of the ~ :~
primary reference documents the secondary reference
documents have become less accurate.
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SU~IARY OF THE INVENTION
The present invention relates to a primary
calibration document replacing the secondary reference ~ -
document and an accurately reproducible method of assigning
MICR signal value to a MICR encoded symbol, replacing the
primary reference document concept. In particular, a
method of assigning an intensity value to a MICR encoded
symbol on a primary document comprises setting up a
magnetic flux under controlled conditions, measuring
magnetic signal level of the flux to arrive at a reference
signal level value, measuring signal level intensity of the
symbol on the document and comparing that signal level
intensity with the signal level of the magnetic flux
reference value. The magnetic ink encoded symbol on the
document is then assigned a magnetic ink test equipment
calibration value.
~ The primary document itself includes at least
; one MICR encoded symbol which according to the method
descrlbed above has an assigned magnetic ink intensity
value~established in reference to a~control~led electrically
~generated magnetic flux level.
~, 30 A printer who prints various different types of
MICR encoded documents such as cheques and the like uses
the above primary calibration document for the purpose of
accurately calibrating MICR test equipment which can then
be used with full assurance of the accuracy of the
equipment to test MICR level intensity of the documents
that have been printed.
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BRIEF DESCRIPTION OF THE DRAWINGS
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The above as well as other advantages and
features of the present invention will be described in
greater detail according to the preferred embodiments of
the present invention in which: ~:
Figure 1 is a front view of a primary document
bearing a MICR encoded ON-US symbol with an assigned or
calibrated value determined in accordance with a preferred
embodiment of the present invention;
Figure 2 is a front view of a piece of equipment
through which an electrical current is passed to produce a
magnetic flux having an intensity which is measured to
provide a reference value from which the calibrated value
on the primary document is established;
Figure 3 is a schematic view of the machinery
used to measure flux level intensity from the piece of
equipment in Figure 2;
Figure 4 is a graph showing the signal level - :-
20 provided when using the device of Figure 2 under controlled :
conditions to generate a reference value signal;
Figure 5 is a front view of a MICR encoded ON-US
symbol; : :
Figure 6 is a graphic representation of the wave ~. :.
: 25 form generated by the ON-US symbol of Figure 5; and
Figure 7 is a graphic representation of the
primary calibration document of Figure 1 calibrated to a
value of 108 relative to the reference value represented by
:: the wave form of Figure 4.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS :
Before going into detail regarding the various
specific features of the present invention, it is to be
understood that the final product achieved by applicant is ~.
a product referred to as a primary calibration document
which is used to ensure accurate measurement by MICR
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reading equipment and in particular, e~uipment calibrated
specifically to read documents bearing a MICR encoded ~-
symbol. The primary calibration document itself is first ~ ~
tested to determine a MICR signal level value which is ~: -
assigned to that document. The calibration document is
then fed to the MICR test equipment which is calibrated to
comply with the accurate value provided on the calibration
document. The now calibrated equipment can be used to
assess whether or not MICR printed documents have a MICR
intensity in a range acceptable to be read by MICR reading
equipment.
The starting point of the entire invention is to
establish control conditions for generating a magnetic flux
having a flux level which produces a MICR value of 100.
This value represents 100 units of signal strength which is
the optimum value for MICR printed documents as established
by industry norms. Calibration documents made in
accordance with the present invention are then compared to
the optimum value and assigned a calibrated value.
By way of example of the above, a calibration
document generally indicated at 1 which is printed on a
paper backing of a shape and size similar to most chegues,
has a MICR encoded ON-US symbol 3 with a calibrated value
of 108 indicated in area 5 on calibration document 1.
Details as to how the calibrated value 108, which is only
8% greater than the optimum value, is arrived at are
described later in the application.
igure 2 shows what is referred to as a wire
card generally indicated at 7. This wire card in its
preferred construction comprises a stiff paper card backing
9 to which a straight cylindrical conductor or wire 11 is
secured by means of tape 13. An electrical current is fed
through the conductor 11 by means of electrical lines 15
connected to a drive current input 17.
Again, according to the preferred construction,
the conductor has a diameter which is equivalent to the
standard dimensions of AMERICAN WIRE GAUGE B&S GAUGE #28
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ANNEALED COPPER of 0.32 mm in diameter. The tape should be
no thicker than 0.002 inches. In addition, a 100 ohm
resistor (+ or 1 percent, .1 watt) may be connected in ~ ~;
series with one end of the wire to facilitate current .
measurement across the wire.
Figure 3 shows a magnetic ink testing device
generally indicated at 21. This device includes what are
known in the industry as a read head 23 and a write head
25. Testing device 21 is used to measure magnetic flux
created by the wire card 7 under controlled conditions.
The first step in the procedure is to run a current of or -~
about 8.6 mA at 5.77 kHz through the wire and place the
wire card on a flat, non-conductive surface near the back
of tester 21. Read head 23 is then manually moved over the
15 center of the wire card with the head touching the wire -
until the maximum signal amplitude is measured on an
oscilloscope forming part of the test equipment and not
shown. The maximum amplitude of the output sine wave which
corresponds to 100% signal level is then recorded. AS
shown in Figure ~ of the drawings, the signal level in this
case is 740 mV.
Test equipment 21, in this example, must then be
set up to read speclfically for the ON-US character which
has a signal pattern peculiar to the ON-US symbol. This is
because the magnetic puIse generated from a MICR encoded
ON-US symbol is proportional to the height of the side of
the stroke which is being read. This, as known in the art,
is well shown in Figures 5 and 6 of the drawings. In
particular, Figure 5 shows an ON-US symbol generally
30 indicated at 27. The characterizing features of the ON-US ;
symbol are that pulses produced because of the shape of the
ON-US symbol are maximum at the third and fifth peaks 29
and 31 respectively in the graphic representation shown in ;~
Figure 6 as seen by a magnetic ink reading of the ON-US
symbol.
In order to calibrate test equipment 21
specifically to an OM-US symbol reading a reference
document having a single ON-US character is fed through the
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test equipment and the height and rotation of the read and ~
write heads are then adjusted to give a maximum output for -
the third and fifth peaks of the pulses produced by the ON-
US character. It is recommended that several tests be run
to ensure accurate set up of the equipment. Furthermore,
during each test, the document itself is magnetized by the
equipment and should be demagnetized for further testing or
measuring purposes. The machine is now ready to test a ~-
document having an encoded MICR symbol to be assigned a
calibration value.
A calibration document to be assigned a value
such as document 1 is fed through the test equipment. The
document complies with the test equipment which is designed
to receive cheques and the like because as noted above, the
document has the shape, size and paper qualities of a
standard cheque. The test equipment as also described
above is now set up to read for the ON-US symbol. The
amplitude of the third and fifth peaks of the pulse
produced by the ON-US symbol on the document are then
measured. The average of several measurements should be
used since there is some variation between tests and some
noise generated by the test results.
he relative signal amplitude for the ON-US
character 3 on document 1 can now be determined by dividing
the~average amplitude of the third and fifth peaks read
from the ON-US symbol by the~maximum amplitude measured
with the~wire card and multiplying by a factor of 100.
For example, as shown in Figure 7 of the
drawings, the average amplitude of the third and fifth
peaks of ON-US symbol l~measures at 800 mv. Returning to
igure 4 of the drawings, the maximum output measured with
the wire card is 740 mV. Accordingly, the relative signal
strength for the calibration document is 800/740 x 100 =
108% for an assigned value of 108 as shown on document 1.
Document l now has an accurately assigned
magnetic ink~intensity value. This document is then fed to
magnetic ink print test equipment (not shown) which is
calibrated to correspond with the 108 value on the
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calibration document. This calibration ensures accuracy of
the print test equipment.
From here, printed documents which have a MICR
encoded symbol are fed through the test equipment. The
test equipment then accurately indicates magnetic ink
intensity of those printed documents to determine whether
or not they are within a range acceptable to industry
standards.
The specific example above relates to
calibrating a document based on signal intensity of an ON-
us symbol encoded on the primary document. It is however
to be understood that other MICR encoded symbols could also
be printed on the document and used for calibration
purposes. The test equipment would then be set up to read
for the particular symbol being calibrated which would have
a different pattern from the ON-US symbol pulse and which
would therefore require different adjustment for the read
and write heads. However, the same principles for
assigning a comparitive calibration value would be used. ;~
Although various preferred embodiments of the
present invention have been described herein in detail, it
will be appreciated by those skilled in the art, that
variations may be made thereto without departing from the
spirit of the invention or the scope of the appended
claims.
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