Tape head with tape-bearing surface exhibiting an array of protruding topographic features

Abstract

A tape head, adapted for reading and/or writing to a magnetic tape, has a tape-bearing surface and is configured to urge a magnetic tape against the bearing surface, in operation. The bearing surface includes a transducer area, having at least one transducer that is a read and/or write element, designed for reading and/or writing to a magnetic tape, and a structured area adjacent to the transducer area, comprising a periodic array of topographic features, the topographic features configured within the structured area to determine a minimal distance between the transducer area and a tape.

1 . A method of implementing tape head distance control for a tape head, adapted for at least one of reading and or writing to a magnetic tape, the tape head having a tape-bearing surface and configured to urge a magnetic tape against the tape-bearing surface, the tape-bearing surface comprising a transducer area having at least one transducer that is at least one of a read element and a write element, and a structured area adjacent to the transducer area, comprising at least two distinct periodic arrays of topographic features on the tape-bearing surface, wherein a first array comprises a first set of topographic features, and a second array that is farther from the transducer area than the first array comprises a second set of topographic features, the first and second sets of topographic features being configured to allow for the tape to get closer to the first array than to the second array, the topographic features configured within the structured area to determine a minimal distance between the transducer area and the tape, the method comprising:
 circulating the magnetic tape with respect to the tape head by streaming the magnetic tape over the tape bearing surface to form an air bearing between the magnetic tape and the tape bearing surface;   sensing, via a thermal sensor circuit, a distance between the tape bearing surface and the magnetic tape; and   altering the distance according to a signal received from the sensor circuit.   
     
     
         2 . The method of  claim 1 , wherein a ratio of an average sectional area of one of the topographic features to the area of a primitive cell of the periodic array is less than 20%. 
     
     
         3 . The method of  claim 1 , wherein a ratio of an average sectional area of one of the topographic features to the area of a primitive cell of the periodic array is less than 1%. 
     
     
         4 . The method of  claim 1 , wherein a ratio of an average sectional area of one of the topographic features to the area of a primitive cell of the periodic array is less than 0.1%. 
     
     
         5 . The method of  claim 1 , wherein the topographic features have, on average, a protruding height between about 10 and 1000 nm. 
     
     
         6 . The method of  claim 1 , wherein the topographic features have, on average, a cross-sectional area diameter between about 100 and 5000 nm. 
     
     
         7 . The method of  claim 1 , wherein an average distance between the topographic features is between about 1 and 20 micrometers. 
     
     
         8 . The method of  claim 1 , wherein the tape-bearing surface comprises one or more layers of material deposited on top of features, conformal thereto, to form the topographic features, the one or more layers comprising one or more of: FeN, TiN, SiN, diamond-like carbon and aluminum oxide. 
     
     
         9 . The method of  claim 1 , wherein at least a subset of the topographic features have a substantially constant cross-section along a height thereof. 
     
     
         10 . The method of  claim 1 , wherein the topographic features comprise one or more of: TiN, Al 2 O 3 —TiC, and FeN. 
     
     
         11 . The method of  claim 1 , wherein topographic features in the structured area are arranged in one or more compartments, each of the compartments comprising an array of topographic features and being enclosed, at least partly, by barriers on the tape-bearing surface. 
     
     
         12 . The method of  claim 1 , wherein the topographic features are connected, defining unconnected empty cells therein, so as to form a honeycomb structure. 
     
     
         13 . The method of  claim 1 , wherein the tape-bearing surface is defined by a flat protruding from a side of the tape-bearing surface so as to come closer to a tape than regions adjacent to the flat, and wherein the head comprises, on the same side and in the vicinity of the flat, one or more of beveled and chamfered regions.