Dual stripe magnetoresistive read heads for speed insensitive tape readers

Two magnetic detectors spaced one-half data cell apart and coupled with the appropriate simple decode electronics can be employed as a read system for Aiken-encoded magnetic tape. The resultant read system will provide output data which are independent of the speed of the magnetic tape relative to the read head (scan speed). If, in addition, the magnetic detectors respond to the magnetic flux from the magnetic tape rather than to changes in the magnetic flux, the read head output becomes totally independent of the scan speed. Such a system is especially useful for applications which require scan speed-independent reading of low density information, as, for instance, with hand-driven, magnetically encoded credit cards.