MR-HEAD HAVING PARASITIC SHIELD FOR ELECTROSTATIC DISCHARGE PROTECTION.

摘要

A MAGNETO-RESISTIVE READ HEAD (107) HAVING A "PARASITIC SHIELD" (124) PROVIDES AN ALTERNATIVE PATH FOR CURRENTS ASSOCIATED WITH SPARKOVERS, THUS PREVENTING SUCH CURRENTS FROM DAMAGING THE READ HEAD (107). THE PARASITIC SHIELD (124) IS PROVIDED IN CLOSE PROXIMITY TO A CONVENTIONAL MAGNETIC SHIELD (113, 115). THE ELECTRICAL POTENTIAL OF PARASITIC SHIELD (124) IS HELD ESSENTIALLY EQUAL TO THE ELECTRICAL POTENTIAL OF THE SENSOR ELEMENT (111). IF CHARGES ACCUMULATE ON THE CONVENTIONAL SHIELD (113, 115), CURRENT WILL FLOW TO THE PARASITIC SHIELD (124) AT A LOWER POTENTIAL THAN WOULD BE REQUIRED FOR CURRENT TO FLOW BETWEEN THE CONVENTIONAL SHIELD (113, 115) AND THE SENSOR ELEMENT (111). (FIG. 6A)