Method and apparatus for reading bar code magnetic ink characters

Claim 2

In a system for recognizing characters with each character having a predetermined number of parallel bars separated by intervals dimensioned as long and short intervals according to a predetermined pattern, a method for determining the widths of said intervals for use in character recognition, comprising the steps: (a) scanning said characters in a direction which is substantially perpendicular to said parallel bars for producing a scanning single having a first polarity when the scanning means scans the leading edge of each of said bars, and also for producing a scanning signal having a second polarity when the scanning means scans the trailing edge of each of said bars; (b) determining peaks in said scanning signals of said first and second polarities; (c) determining a zero crossing point between a said peak of said first polarity in a scanning signal and a said peak of said second polarity in the scanning signal associated with each one of said bars for a character; and (d) measuring the intervals between the zero crossing points of said bars to determine whether a long or short interval exists between the parallel bars making up a character.

Claim 3

The method as claimed in claim 1 in which said determining step c includes the step of: (c-1) storing the values of said peaks and also storing counts which correspond to the distances or intervals between said peaks.

Claim 4

The method as claimed in claim 2 in which said measuring step d includes the steps of: (d-1) determining whether any of said intervals is longer than one of said intervals dimensioned as a long interval according to said predetermined pattern; and (d-2) if one of said intervals is longer as defined herein, rejecting the associated said character.

Claim 5

The method as claimed in claim 3 in which said measuring step d includes the steps of: (d-3) determining whether any of said intervals is shorter than one of said intervals dimensioned as a short interval according to said predetermined pattern; and (d-4) if one of said intervals is shorter as defined herein, rejecting the associated character.

Claim 6

The method as claimed in claim 4 in which said measuring step d includes the steps of: (d-5) ranking said counts corresponding to said intervals from the lowest count to the highest count; and (d-6) selecting the second highest count as representing the dividing line between a long and short interval.

Claim 7

The method as claimed in claim 5 in which said measuring step d includes the steps of: (d-7) classifying said counts as long intervals if they are equal to or greater than said second highest count; and (d-8) classifying said counts as short intervals if they less than said second highest count.

Claim 8

In a system for recognizing characters with each character having a predetermined number of parallel bars separated by intervals dimensioned as long and short intervals according to a predetermined pattern, a method for determining the widths of said intervals for use in character recognition, comprising the steps: (a) scanning said characters in a direction which is substantially perpendicular to said parallel bars for producing a scanning signal having a first polarity when the scanning means scans the leading edge of each of said bars, and also for producing a scanning signal having a second polarity when the scanning means scans the trailing edge of each of said bars; (b) determining peaks in said scanning signals of said first and second polarities; (c) determining a zero crossing point between a said peak of said first polarity in a scanning signal and a said peak of said second polarity in the scanning signal associated with each one of said bars for a character; and (d) measuring the intervals between the zero crossing points of said bars to determine whether a long or short interval exists between the parallel bars making up a character; (e) rejecting those characters whose intervals cannot be determined by steps c and d; (f) measuring the intervals between the trailing edge of one bar to the trailing edge of the next adjacent bar for those bars associated with a character rejected at step e to determine whether a long or short interval exists between the parallel bars making up the rejected character from step e.

Claim 9

In a system for recognizing characters with each character having a predetermined number of parallel bars separated by intervals dimensioned as long and short intervals according to a predetermined pattern, a method for determining the widths of said intervals for use in character recognition, comprising the steps: (a) scanning said characters in a direction which is substantially perpendicular to said parallel bars for producing a scanning signal having a first polarity when the scanning means scans the leading edge of each of said bars, and also for producing a scanning signal having a second polarity when the scanning means scans the trailing edge of each of said bars; (b) determining peaks in said scanning signals of said first and second polarities; (c) determining a zero crossing point between a said peak of said first polarity in a scanning signal and a said peak of said second polarity in the scanning signal associated with each one of said bars for a character; and (d) measuring the intervals between the zero crossing points of said bars to determine whether a long or short interval exists between the parallel bars making up a character; (e) rejecting those characters whose intervals cannot be determined by steps c and d; (f) measuring the intervals between the trailing edge of one bar to the trailing edge of the next adjacent bar for those bars associated with a character rejected at step e to determine whether a long or short interval exists between the parallel bars making up the rejected character from step e.

Claim 10

The method as claimed in claim 7 in which said steps a through d are effected while a document carrying said characters thereon is moving in a document track.

Claim 11

The method as claimed in claim 8 in which said measuring step f is effected after a character is rejected while using said steps c and d.

Claim 12

In a system for recognizing characters with each character having a predetermined number of parallel bars separated by intervals dimensioned as long and short intervals according to a predetermined pattern, an apparatus for determining the width of said intervals for use in character recognition, comprising: scanning means for scanning said characters in a direction which is substantially perpendicular to said parallel bars for producing a scanning signal having a first polarity when the scanning means scans the leading edge of each of said bars, and also for producing a scanning signal having a second polarity when the scanning means scans the trailing edge of each of said bars; first means for determining peaks in said scanning signals of said first and second polarities; second means for determining a zero crossing point between a said peak of said first polarity in a scanning signal and a said peak of said second polarity in the scanning signal associated with each one of said bars for a character; and third means for measuring the intervals between the zero crossing points of said bars to determined whether a long or short interval exists between the parallel bars making up a character.

Claim 13

In a system for recognizing characters with each character having a predetermined number of parallel bars separated by intervals dimensioned as long and short intervals according to a predetermined pattern, an apparatus for determining the width of said intervals for use in character recognition, comprising: scanning means for scanning said characters in a direction which is substantially perpendicular to said parallel bars for producing a scanning signal having a first polarity when the scanning means scans the leading edge of each of said bars, and also for producing a scanning signal having a second polarity when the scanning means scans the trailing edge of each of said bars; first means for determining peaks in said scanning signals of said first and second polarities; second means for determining a zero crossing point between a said peak of said first polarity in a scanning signal and a said peak of said second polarity in the scanning signal associated with each one of said bars for a character; and third means for measuring the intervals between the zero crossing points of said bars to determined whether a long or short interval exists between the parallel bars making up a character.

Claim 14

The apparatus as claimed in claim 10 in which said first means includes a threshold means for thresholding said scanning signals of said first and second polarities to obtain thresholded scanning signals which exceed a predetermined level, and in which said first means also includes an A/D converter for converting said thresholded scanning signals to digital values.

Claim 15

The apparatus as claimed in claim 11 in which said second means comprises: counting means for determining a count which reflects an interval between said thresholded scanning signals of said first and second polarities for a character; storing means for storing said counts and said digitized values for said thresholded scanning signals; and calculating means for determining zero crossing points for each of said bars in a character by using said counts and said digitized values of said thresholded scanning signals.