| abstract |
A disc drive (100) that includes a slider (300,501) with a field emission sensor (312,512) that senses fly height. The sensor (312,512) has an electrode tip (302) disposed on the slider (300,501). The electrode tip (302) faces a media surface (306) across a gap (316,516). The sensor (312,512) conducts a tunneling current through the gap and provides an output representing the length of the gap (316,516). An actuator (330,502) adjusts the fly height spacing. A feedback circuit (410,420,506,1520) provides an actuator electrical input as a feedback function of the sensor output to control the fly height spacing. |