Recovery of normally illegible, magnetically recorded information

Abstract

Illegible information recorded along a track of a magnetic record medium is recovered by relatively moving the read head from its normal position at the approximate center of the track to a new position at an edge of the track and then creating relative movement between the head and record medium in the track direction.

What is claimed is: .[.1. In a system for reading a relatively wide record track on a record medium with a relatively narrow read head located at the approximate center of the track by creating relative movement between the record medium and head, in the track direction, in combination: 
     
        direction..]. 3. In a system as set forth in claim .[.2.]. .Iadd.8.Iaddend., said record medium comprising a plastic card formed with a magnetic recording surface. .[.4. Apparatus for reading information from a record track of a kind susceptible to information damage extending part way across the track comprising, in combination: a reading head located adjacent to and between the edges of said track for reading along an area of the track of width relatively narrower than the track width;   means for creating relative movement in the track direction between the track and head to permit said head to read said relatively narrow area of said track; and   means responsive to detection of an error due to said damage in the information read from said relatively narrow area by said head for causing at least the error containing section of the length of the track to be re-read along a second relatively narrow area still over the same track but laterally shifted in the track relative to the first read area..]. .[.5. In a system for reading by means of a head along the length of a track on a record medium by creating relative movement between the medium and the head, at least a portion of said head being positioned in signal reading relationship over at least a portion of the width of said track;   an error detection means responsive to a signal read from said track by said head for detecting an error; and   means responsive to said detected error for creating lateral relative movement between said head and said track such that said head is in a signal reading relationship over a different portion of the wdith of said track as compared to the original position of said head, and for causing said head to again read said track where said signal was originally read but with said head over said different portion of the width of said   
     
     
        track..]. .[.6.  In a system as set forth in claim 5, further including means responsive to an error detected by the error detection means for again creating lateral relative movement between said head and track in a direction opposite the direction of the first mentioned lateral move such that said head is over a different portion of the width of said track than was the head in its original position and its position after the first mentioned lateral move, and for causing said head to again read said track where said signal was originally read but with said head in a new lateral position relative to said track resulting from the second mentioned 
     
     
        lateral move..]. 7. In a system as set forth in claim .[.6.]. .Iadd.9.Iaddend., said record medium comprising a substantially flat member formed with a magnetic recording surface. .Iadd. 8. In a system for reading a relatively wide record track on a record medium with a relatively narrow read head located at the approximate center of the track by creating relative movement between the record medium and head, in the track direction, in combination: error detection means responsive to the information read by the read head for detecting an error;   means responsive to an error detected by the error detection means for creating relative movement between the read head and track in a direction transverse to the track, and in an amount such that the head is still over the same track, but relatively closer to an edge portion thereof than the head was in its original position, and for again creating relative movement between at least the portion of the record medium containing the error and the head, in the track direction; and   means responsive to an error still present for creating relative movement between the read head and track in a direction transverse to the track and in an amount and direction such that the head is still over the same track, but relatively closer to the other edge portion thereof than the head was in its original position, and for a third time creating relative movement between at least the portion of the record medium containing the error and the head, in the track direction. .Iaddend..Iadd. 9. In a system for reading by means of a head along the length of a track on a record medium by creating relative movement between the medium and the head, at least a portion of said head being positioned in signal reading relationship over at least a portion of the width of said track;   an error detection means responsive to a signal read from said track by said head for detecting an error;   means responsive to said detected error for creating lateral relative movement between said head and said track such that said head is in a signal reading relationship over a different portion of the width of said track as compared to the original position of said head, and for causing said head to again read said track where said signal was originally read but with said head over said different portion of the width of said track; and   further including means responsive to an error detected by the error detection means for again creating lateral relative movement between said head and track in a direction opposite the direction of the first mentioned lateral move such that said head is over a different portion of the width of said track than was the head in its original position and its position after the first mentioned lateral move, and for causing said head to again read said track where said signal was originally read but with said head in a new lateral position relative to said track resulting from the second mentioned lateral move. .Iaddend.