Abstract Magnetically saturated, magnetic ink characters on a check blank are passed by a mechanical check handler under a magnetic read head. A positive signal is generated in the head each time it moves into a segment of more ink, and a negative signal is generated each time the head moves into a segment of less ink. The magnitude of these signals depends upon the magnitude of the difference in the amount of ink detected by the magnetic read head as it makes the transition from one segment of each character to the next. The coding of the magnetic characters is such that a plurality of adjacent segments vary abruptly in magnitude. However, the magnitude of the change between some adjacent segments and consequently the magnitude of the transition signals, will be substantially smaller than the magnitude between other adjacent signals. These smaller, weaker signals can sometimes be lost. Each character in which such smaller signals and hence the possibility of errors can occur is identified by a plurality of composite binary codes, each one representing one of the possible signal combinations resulting from the loss or capture of every possible combination of weak signals. In some cases the same composite binary code represents more than one character. In these cases, direction (positive or negative) of the signals generated by the read head is used to differentiate between such signals to unambiguously identify the particular character.
A method of identifying particular magnetic characters from a predetermined set of characters having adjacent segments of greater and lesser totality of magnetic flux across the characters in a first direction including the steps of: A. recording and locating within a memory a separate signal code representative of each of the predetermined characters and associating a separate predetermined address with each of said signal codes within this memory; B. moving the magnetic characters relatively past a magnetic read head in said first direction; C. obtaining from said read head a signal trace indicative of the signals generated as the adjacent segments move relatively past the head; D. deriving a signal trace function; E. using said function of said signal trace to address a location within said memory; F. deriving the signal code located at said address and representative of a particular character; and G. transmitting said signal code to a location for use.
Claim 2
Independent Claim
153 words
A method of identifying particular magnetic characters from a predetermined set of characters having adjacent segments of greater and lesser totality of magnetic flux across the characters in a first direction including the steps of: A. recording and locating within a memory a separate signal code representative of each of the predetermined characters and associating a separate predetermined address with each of said signal codes within this memory; B. moving the magnetic characters relatively past a magnetic read head in said first direction; C. obtaining from said read head a signal trace indicative of the signals generated as the adjacent segments move relatively past the head; D. deriving a signal trace function; E. using said function of said signal trace to address a location within said memory; F. deriving the signal code located at said address and representative of a particular character; and G. transmitting said signal code to a location for use.
Claim 3
Dependent Claim
155 words
The method of claim 1 wherein the magnetic characters are encoded in magnetic ink on a non-magnetic sheet and each character includes a plurality of segments, each segment having uniform individual totality of magnetic ink in direction transverse to said first direction, each segment being in contiguous relation to at least one other similar segment of different uniform totality of such ink in said transverse direction; the additional step of magnetically saturating the characters in one direction; wherein the step deriving the signal trace function includes the acquisition of a positive directional signal trace function representative of increases in magnetic flux and a negative directional signal trace function representative of decreases in such flux and includes acquisition of signal trace functions representative of the magnitude of such changes; and wherein the step of using the signal trace function to address a location within the memory includes use of the directional aspects of signal trace functions.
Claim 4
Dependent Claim
132 words
The method of claim 2 wherein some of the flux changes between segments of particular characters are of such small magnitude that the signal trace functions of such characters can sometimes fail to recognize such change; wherein the directional signal trace functions are added to obtain a composite signal trace function; wherein the prerecorded addresses include addresses corresponding to each possible combination of composite signal trace functions of each character resulting from all possible combinations of recognizing and failing to recognize such small magnitude changes, at least some of such composite signal trace functions identifying more than one character; and wherein the step of deriving said signal code representative of a particular character includes utilizing one of said directional signal trace functions to differentiate between characters having identical composite signal trace functions.