Archive Corporation

Siliconsystems, Inc.

Anatoly Aranovsky

William A Buchan

An amplifier for biasing and amplifying the signals produced by a magnetoresistive element is provided. The input stage of this circuit includes two transistors in a differential common base configuration having a low input impedance. Since the two transistors are coupled to separate identical current sources, balance between the currents through the two transistors is maintained. The currents are balanced without the use of a feedback loop. Additional input stages may be added to allow signals from additional magnetoresistive elements to be selected and amplified. By using a common mode switching configuration, switching transients are greatly reduced.

Magnetoresistive head amplifier

In a magnetic sensing head with reduced crossfeed interference circuitry, the winding of each half of a magnetic core of the head is wound in the same direction as the other about the core. Each winding is coupled to an individual differential amplifier and the output of each amplifier is fed to another differential amplifier which provides the head output substantially unaffected by interference signals picked up by the head. Both magnetically coupled and stray capacitive interference are compensated.

Electromagnetic head having interference compensation circuitry

A method is provided to compensate for tape slope (A) and read/write head block (102) azimuth (B) errors in a tape drive system (100). The method writes a data pattern (504) on a magnetic medium (104) at a known slope (C). The portion of the magnetic medium (104) that is encoded with the data pattern (504) is then moved across the read/write head block (102), so that first one read head (154) and then the other read head (152) detects the recorded data pattern (504). The time difference (.DELTA.T.sub.ON) between the event of each head (154, 152) first sensing the data pattern (504), and the time difference (.DELTA.T.sub.OFF) between the points where each head (154, 152) no longer detects the data pattern (504), are both recorded. The recorded information is used to analyze the angular offset (A-B) between the centerline (192) of the tape (104) and the centerline (194) of the read/write head system (102). The angular offset (A-B) is used to determine a lateral displacement (D) between the two read heads (154, 152) in a direction perpendicular to the centerline (192) of the tape (104). The lateral displacement (D) is used to adjust the stepping distance between data tracks recorded in a first (i.e., forward) direction and a second (i.e., reverse) direction on the tape (104) so that the respective read head (152, 154) is positioned substantially on the center of the respective recorded track.

Growing community of inventors

Tustin, CA, United States of America

Anatoly Aranovsky