Optical servo system for a tape drive

In a tape drive, a system for aligning a read/write head with a selected set of a plurality of data tracks written on a first side of a tape as said tape passes over said read/write head, wherein said tape also includes optical servo features formed on a second side of said tape, said system comprising:

• means for reading said optical servo features from said second side of said tape;
• and
• means, responsive to said read optical servo features, for aligning said read/write head with said selected set of a plurality of data tracks on said first side of said tape, wherein said second side of said tape has formed thereon auxiliary information from the class of tape auxiliary information including but not limited to:
• encryption/authentication data, tape identification data, maintenance information, read only data.

In a tape drive, a method for aligning a read/write head with a selected set of a plurality of data tracks written on a first side of a tape as said tape passes over said read/write head, wherein said tape also includes optical servo features formed on a second side of said tape, said system comprising the steps of:

• reflectively illuminating said optical servo features from said second side of said tape;
• reading said optical servo features from said second side of said tape;
• aligning, in response to said read optical servo features, said read/write head with said selected set of a plurality of data tracks on said first side of said tape;
• wherein said read/write head has a plurality of optical features formed thereon or affixed thereto, further comprising the step of:
• reading said optical features from said read/write head;
• and
• wherein said step of aligning is responsive to said read optical servo features from said second side of said tape and said read optical features from said read/write head.

In a tape drive, a system for aligning a read/write head with a selected set of a plurality of data tracks written on a first side of a tape as said tape passes over said read/write head, wherein said tape also includes optical servo features formed on a second side of said tape, said system comprising:

• means for reflectively illuminating said optical servo features from said second side of said tape;
• means for reading said optical servo features from said second side of said tape;
• and
• means, responsive to said read optical servo features, for aligning said read/write head with said selected set of a plurality of data tracks on said first side of said tape;
• wherein said read/write head has a plurality of optical features formed thereon or affixed thereto, and further comprising:
• means for reading said optical features;
• and
• wherein said means for aligning is responsive to non-overlapping images of said read optical servo features and said read optical features.

In a tape drive, a system for aligning a read/write head with a selected set of a plurality of data tracks written on a first side of a tape as said tape passes over said read/write head, wherein said tape also includes optical servo features formed on a second side of said tape and said read/write head has a plurality of optical features formed thereon or affixed thereto, said system comprising:

• means for reading said optical servo features reflected from said second side of said tape;
• means for reading said optical features reflected from said read/write head;
• and
• means, responsive to said read optical servo features from said second side of said tape and said read optical features from said read/write head, for aligning said read/write head with said selected set of a plurality of data tracks on said first side of said tape.

In combination:

• a tape having regions of differing reflectivity on a side thereof;
• a tape head having regions of differing reflectivity;
• and
• an optical servo system that views an image of the tape and tape head to effectuate alignment between the tape and tape head, wherein the image is non-overlapping.

In combination:

• a tape having regions of differing phase on a side thereof;
• a tape head having regions of differing phase;
• and
• an optical servo system that views an image of the tape and tape head to effectuate alignment between the tape and tape head, wherein the image is non-overlapping.