Method and apparatus for detecting asperities on magnetic disks using thermal proximity imaging

摘要: A method and apparatus for mapping the character location of small surface variations on a planar surface. Energy is supplied to an object in close proximity thereby raise temperature object. The moved with respect planer substantially constant. decrease detected when it variation define variation. energy supply may be thermal or optical but preferably electrical which heats resistive element. Preferably, magnetoresistive head disk drive assembly. that magnetic recording material. change by monitoring resistance coil head. pulses obtain higher peek temperatures while avoiding mechanical distortion It preferred positioned so relative motion between occurs, does not contact