MICR Waveform analyzer

• US 4,245,211 A
• Filed: 11/13/1978
• Issued: 01/13/1981
• Est. Priority Date: 11/13/1978
• Status: Expired due to Term

• Current Assignee: Bantec Incorporated
• Original Assignee: Recognition Equipment Incorporated
• Inventors: Kao, Charles T.
• Primary Examiner(s): Boudreau, Leo H.
• Application Number:
  US05/959,970
• Time in Patent Office: 792 Days
• Field of Search: 340/146.3 C, 340/146.3 AC, 340/146.3 Z, 235/449
• US Class Current: 382/139
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06V 30/144 using a slot moved over the image; using discrete sensing elements at predetermined points; using automatic curve following means
• CPC Class Codes: G06V 30/196 using sequential comparisons of the image signals with a plurality of references
• CPC Class Codes: G06V 30/2253 Recognition of characters printed with magnetic ink G06V30/2247 takes precedence

Abstract

A MICR waveform analyzer for reading E-13B magnetic ink characters including a digital phase lock loop to locate the character, a Normalizer to compress data and equalize ink strength dynamic range, and a waveform amplitude analyzer to identify the magnetically read character is described.

Claims

1. A waveform analyzer for reading magnetic ink characters wherein an electrical video signal is produced as the characters pass a pickup head, said video signal containing character data and possibly error data signals, comprising:

means for integrating the video signal representative of an entire magnetic ink character to produce a character waveform;

processing means for digitizing and then normalizing the digitized character waveform to normalize character ink strength variations; and

sampling means for locating and selecting samples of the digitized character waveform as distinct from error data signals to present to a recognition system.

2. The analyzer according to claim 1 wherein said sampling means includes a peak detector and phase lock loop, the phase lock loop locking onto valid peak pairs produced by said peak detector.

3. The sampling means according to claim 1 including horizontal location logic circuits for horizontally locating the character data waveform signals for each character.

4. The analyzer according to claim 1 wherein the means for integrating is reset at the beginning of each character read.

5. The analyzer according to claim 2 wherein the phase lock loop locks onto peaks which are 13 mils apart or multiples of 13 mils.

6. A waveform analyzer for reading magnetic ink characters wherein a video signal is produced as the characters pass a pickup head, said video signal containing character data and possibly error data signals, comprising:

an integrator circuit for integrating the video signal over a character period to produce a character waveform signal,

an analog to digital converter for digitizing said character waveform signal;

a time delay circuit for delaying the waveform signal;

a time delay circuit for delaying the integrated and digital character waveform signal for one character period;

a normalizer for amplitude normalizing the character waveform signal;

a peak detector for detecting peaks in the video signal;

a phase lock loop for locking onto valid pairs of peaks resulting from scanning a character; and

a horizontal location circuit for identifying a character horizontally within the video signal,

wherein the character waveform is gated by the horizontal location circuit for identifying the character producing the video signal.