A system for reading a data record stripe on a credit card which includes an injection molded case including a card guide slot integrally molded into the case near one side thereof and a read head window integrally formed in one sidewall of the card guide slot. A data read head assembly having a read head on a front face thereof is mounted in the read head window and is spring biased toward the wall of the card slot opposite the read head window. A circuit arrangement is coupled to the read head assembly for detecting data signals on a card passing through the slot and converting the data signals to a substantially square wave signal pattern representing binary signal data in the form of positive and negative signal transitions of the square wave signal. A microcomputer circuit coupled to the circuit arrangement is programmed to detect positive and negative signal transitions, to register in individual memory locations the time interval between successive signal transitions, and to reconstruct the binary signal data from the pattern of the registered time intervals.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of my copending U.S. application Ser. No. 07/0852,287 filed Aug. 10, 1987 (now U.S. Pat. No. 4,788,420), which is a continuation of copending U.S. application Ser. No. 06/770,725, filed Aug. 28, 1985 (now abandoned).
A reading head mounting arrangement is disclosed. The arrangement comprises a base having a top surface and extending from a side thereof an upright mounting member for mounting of a reading head in proper spaced relationship from the top surface of the base for reading of a information containing stripe attached to a card. Preferably, the base has downwardly projecting portions at either end thereof to provide on and off ramps for a credit card being slid over the base, whereby when the arrangement is installed in a magnetic stripe reading terminal having a slot for passage of a credit card past a magnetic stripe reading head, the change in elevation of the base relative to the remainder of the slot provides a user of the terminal with positive feedback that the card is properly positioned in the slot. Accuracy in positioning the strip for movement past the magnetic head is predetermined during the manufacture of the mounting arrangement. The arrangement is used for mounting of a magnetic read head which may then be utilized in a terminal for providing authorization by a card issuer of the use of the card.
A process of scanning and evaluating binary data stored on a magnetic track of a magnetic storage card includes a calibration at the beginning of the scanning operation with certain information stored on the card and a determination of a calibrated time interval. A time curve of the output signal in the calibrated time interval is registered and compared to predefined curve patterns in order to determine deviation of the registered time curve from the curve patterns. A curve pattern showing a least deviation from the registered time curve is identified. The curve pattern may be selected on the basis of information obtained from a previously determined output signal curve. Also, the extreme values are detected to obtain information stored on the card.
A data terminal having a card reader assembly for reading a data card having at least a pair of magnetic stripes formed thereon at adjacent ones of at least three defined magnetic data track locations thereon. The terminal includes a read head having two magnetic pickup elements on a front face thereof, the pickup elements being separated by a distance corresponding generally to the distance between the separated magnetic data track locations on the data card. A housing assembly defines a card guide slot adapted to guide a data card during a manual swipe of the card through the card reader assembly. The card guide slot comprises first and second opposite side wall sections and a bottom wall section with one of the side wall sections defining an access aperture for admiting the read head into the card guide slot. A read head positioning arrengement is cooperatively associated with the card guide slot for mounting the read head in a preselected position relative to the bottom wall section of the card guide slot such that the magnetic pickup elements are positioned for detecting a prearranged set of magnetic data tracks located at one of the upper two data track locations and the lower two data track locations.
A method for decoding F2F signals as well as a device for decoding F2F signals read from a magnetic data carrier is provided. The signal read from the card by a magnetic reading head is amplified by an amplifier with a very high gain, discriminated in a discrimination and integration station to receive a binary looking signal. Out of this digitized signal in a reference time acquisition station a start-up time value is set and a phase is estimated to determine the correct end of a bit cell in a phase estimating station. In a symbol correlation station the received binary signal is correlated with all possible symbol combinations based on the estimated phase to create a correct bit stream. This bit stream might be processed further by a bit recovery station providing a corrected bit stream ready for interpretation.
A magnetic stripe decoder includes an amplitude discrimination circuit to remove noise due to glitches. The use of amplitude discrimination rather than a filter, which is in common use today, permits a single decoder circuit to decode data over a wide range of frequencies including the standards 75 BPI and 210 BPI. In the absence of such an amplitude discriminator, two different decoders, one for 75 BPI and one for 210 BPI are necessary.
