Ncr Corporation

Axiohm Transaction Solutions, Inc.

Axiohm Ipb Inc.

John G Mitchell

Kathleen Maginnity

James R Del Signore, Ii

Robert Delaney

Andrew B Nye, Iii

Thomas Parent

James Del Signore

William M Schmid

Terrence J Campbell

Commercial establishments that add MICR indicia to commercial instruments usually do so via laser printers that produce a high gain signal. Moreover, commercially printed documents that include MICR indicia can also result in a high gain signal. MICR indicia generated by laser printers are difficult to decode, using conventional DC biasing methods, because the laser-generated MICR high gain signals become clipped. Therefore, in order to decode these distorted signals, the present system processes both low and high gain signals to decode the raw MICR data.

System for and method of reading MICR using high and low gain signals

There is provided a method for monitoring paper or other jams of a carriage in a printer by monitoring the current waveshape in a first winding of a stepper motor at or near the time when a second winding of the stepper motor commutates. The current waveshape is received from a low-value sensing resistor, typically within an integrated circuit stepper motor driver device. Changes in the current waveshape during this time window may be interpreted and accurate deductions may be made concerning the loading of the stepper motor. In the case where the stepper motor is the drive motor for a printer carriage, the loading information may be used to detect a paper jam or similar problem in the printer carriage.

Printer carriage jam detector using sensed motor current

The present invention features a check-reading and check-validation machine having a programmed microprocessor, a photo-sensor, a magnetizing unit, a magnetic head reader, feed rollers and a stepper motor drive for rotatively driving the feed rollers. The machine may be a sub-unit of a printer. A check is introduced to the nip of the feed rollers. The photo-sensor detects the presence of the check and activates the stepper motor drive. The stepper motor drive then causes the feed rollers to rotate, drawing the check into the reading and validating machine. The microprocessor instructs the stepper motor to feed and discharge the check into and out of the machine, according to a specialized program. The microprocessor program initially instructs the stepper motor to rotate the feed rollers for forward drive, utilizing half-step pulsing. As the check moves past the magnetizing unit and the magnetic head reader, on forward motion into the reading and validating machine, magnetic characters on the check are magnetized. After the calculated number of pulses required for the check to pass the magnetizing unit and the magnetic head reader, the program instructs a reverse-drive direction for the stepper motor, and a simultaneous change of drive phase to wave-drive stepping. The check is read as it is discharged from the machine at a constant speed.

Check-reading machine

The present invention features a method and a fixture for determining the asymmetrical character of a readhead prior to its installation in a check-validation machine. Such a machine that is used to validate checks uses a stepper motor drive to convey the check past the readhead. The magnetic field produced by the coil of the stepper motor interferes with the capability of the readhead to recognize the magnetic indicia on the check. Once determined, the asymmetrical sensitivity of the readhead towards the magnetic flux allows the manufacturer to mount the readhead with its sensitive side away from the stepping motor of the validating unit. The readhead asymmetry is determined by the method of this invention by measuring an output voltage pulse of the readhead, when it is excited by magnetic pulses both forward and rear of its read gap. The excitation is provided approximately one inch from the read gap. The exciting pulses are of similar magnitude and timing as that of the signal field generated by the slip drive of the stepper motor. The peaks of the forward and rear output pulses are converted into DC voltage levels, which are then fed into a comparator circuit. The comparator circuit controls the lighting of a 'go/no go' indicator LED, which tells the operator which side of the readhead is more sensitive to the magnetic flux.

Method and apparatus for improving readhead performance

A method and apparatus including a circuit for measuring the displacement of an electromagnetic device wherein the measuring is effected by utilizing the perturbations which occur in the energizing current of the device when the moveable member contacts a second member during a 'gap' measurement, for example. The circuit includes circuitry for obtaining a first derivative signal having indicator portions corresponding to the perturbations. An apparatus including a test block is used for testing center-to-center distances.

Method and apparatus for measuring displacement of a moveable member of

A center-to-center distance measuring device for measuring the exact spacing between print solenoids. The devie uses a test block having a top surface and a bottom surface which are parallel. The top surface has first and second bevel surfaces which are parallel to each other, extend from the top surface towards the bottom surface and are spaced apart at a predetermined distance. The print solenoids are positioned perpendicularly to the top surface of the test block such that the print wires of the print solenoids impact against the test block when energized. The displacement of the print wires from the solenoids is used to determine the center-to-center spacing as the print wires impact against the bevel surfaces as the test block is moved.

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Ovid, NY, United States of America

John G Mitchell