DISTANCE-CONTROLLED TUNNELING TRANSDUCER AND DIRECT ACCESS STORAGE UNIT EMPLOYING THE TRANSDUCER

摘要

This distance-controlled tunneling transducer (1) comprises a plurality of sharply pointed tips (2) arranged in an array at tunneling distance from the electrically conductive surface (6) of a storage medium (7). Each tip (2) is attached to a cantilever beam (3) permitting the distance between each tip (2) and the surface (6) to be individually pre-adjusted by electrostatic means (8, 9). Arranged in juxtaposition with each cantilever beam (3) is a simple active control circuit (12, 13, 16) for adjusting the tip/surface distance during operation of the storage unit thus preventing crashes of the associated tip (2) into possible asperities on the surface (6) of the recording medium (7). Each control circuit (12, 13, 16) is designed such that its operating voltage, at thesame time, serves to pre-adjust its associated cantilever beam (3) and to maintain the gap width essentially constant.