Adjustment system for multiple magnetic read head - has four extra read heads for four control tracks used for adjusting main heads

摘要

The adjustment system has control tracks on the magnetic carrier parallel to the data tracks and alternating in magnetisation direction from section to section. The multiple head has extra read heads for the control tracks. The output signals from these extra read heads are passed to a setting device that adjusts the head support to compensate for errors. Four control tracks are equally spaced across the record carrier and each control track has its own extra read head containing a detector. The detectors are located in the four arms of a bridge circuit whose diagonal contains an evaluator that produces the control signal for the setting device.