Eastman-kodak Company

Jay D Marchetti

John J Acello

John J Bradley

Richard H Bolton

Richard C Painton

A servomechanism finds an optimum location for a transducer relative to a track on a magnetic disk by sampling signal strength for a plurality of transducer trajectories. By processing the amplitude envelope of the recorded signal through a comparator prior to sampling, the comparator output, rather than the continuous signal envelope, is sampled. In this way a manageable amount of data is produced for tabulating a collection of integers that specify the cross-track distribution of signal strength across the trajectories. The best trajectory is selected and the transducer is moved accordingly to obtain the best playback signal.

Track-finding servomechanism utilizing the sampled output of an envelope

A video player includes a playback head that repeatedly passes in contact with a circular track on a flexible magnetic disk in order to reproduce a still picture on a video display. By cycling the player into a special quiescent state after a certain interval elapses without user instructions, excessive disk wear is avoided. While in the quiescent state, the disk drive motor is stopped--immobilizing the disk-to-head interface--and the video display is blanked. If user instructions are received while in this state, the disk drive motor is reenergized and the video display is resumed, showing the still picture displayed prior to interruption. If no user instructions are received during a further interval, the player is shut off.

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Rochester, NY, United States of America

Jay D Marchetti