Multi-channel magnetic tape system having optical tracking servo

• US 20020186496A1
• Filed: 07/17/2002
• Published: 12/12/2002
• Est. Priority Date: 03/24/1998
• Status: Active Grant

• Current Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Original Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Inventors: Cappabianca, Leo, Saliba, George A., Kim, Chan, Mallick, Satya A., Turgeon, Carol, Cronis, Lewis
• Granted Patent: US 7,110,210 B2
• Time in Patent Office: Days
• US Class Current: 360/77.01
• CPC Class Codes: G11B 5/5926 recorded in separate tracks, e.g. servo tracks

Abstract

A magnetic storage medium formed on a front major surface of a tape substrate defines a multiplicity of longitudinal data recording and playback tracks, each track having a nominal lateral location relative to the other tracks: and a predetermined optically manifested track servo pattern defined on the back major surface of the tape for indicating lateral displacement of the tape from a nominal lateral location of the track during tape movement across a read/write head. A magnetic tape recording and playback system employing the magnetic storage medium is also disclosed.

Claims

1. A spool of magnetic recording tape comprising:

an elongated continuous web of flexible plastic substrate material having two edges and defining a front major surface and a back major surface,

a magnetic storage medium formed on the front major surface, the magnetic storage medium for defining a multiplicity of longitudinal data recording and playback tracks each said track having a nominal lateral location relative to the other tracks,

a predetermined optically manifested track servo pattern defined on the back major surface, the pattern for indicating actual lateral displacement of the tape away from a nominal lateral location of a said track during tape movement across a read/write head.

2. The magnetic recording tape set forth in claim 1 comprising one half inch width magnetic recording tape and the multiplicity of tracks comprising at least 1000 tracks.

3. The magnetic recording tape set forth in claim 1 wherein the optically manifested track servo pattern is applied during manufacture of the tape.

4. The magnetic recording tape set forth in claim 1 wherein the optical pattern is formed by printing.

5. The magnetic recording tape set forth in claim 1 wherein the optical pattern is formed by embossing.

6. The magnetic recording tape set forth in claim 1 wherein the optical pattern is formed by patterning/ablation by a laser beam.

7. The magnetic recording tape set forth in claim 1 wherein the optical pattern is formed by selective deposition of light-reflective material.

8. The magnetic recording tape set forth in claim 1 wherein the optical pattern is formed by selective deposition of light-absorptive material.

9. An information storage medium comprising:

a linear magnetic tape medium having a first surface accessible by a laterally positionable, multi-head magnetic read/write transducer assembly, and a second surface accessible by an optical servo transducer assembly physically coupled to the magnetic read/write transducer assembly,

a multiplicity of linear data tracks defined on the first surface, each linear track for storage of magnetic data patterns written by a head of said magnetic read/write transducer positioned and maintained thereat by a lateral head positioner,

a multiplicity of linearly extending servo features defined on the second surface and read by the optical servo transducer for generating a servo feedback signal to aid track following by the magnetic read/write transducer as the tape medium is drawn there across.

10. A magnetic tape recording and playback system for recording data onto a magnetic recording tape, and reading data from the tape, via a magnetic head structure across which the tape is moving along a tape path within the drive, wherein the magnetic head structure is positionable transversely relative to the direction of tape travel along the tape path in order to register with a multiplicity of lineal tape track positions,

the magnetic recording tape comprising:

an elongated continuous web of flexible plastic substrate material having two edges and defining a front major surface and a back major surface,

a magnetic storage medium formed on the front major surface, the magnetic storage medium for defining a multiplicity of longitudinal data recording and playback tracks, each said track having a nominal lateral location relative to the other tracks, and

a predetermined optically manifested track servo pattern defined on the back major surface, the pattern for indicating actual lateral displacement of the tape away from a nominal lateral location of a said track during tape movement across a read/write head; and

,

the tape system comprising;

a support base,

a head carriage positionable relative to the support base and laterally relative to the tape path,

coarse positioning means mounted to the support base for moving the head carriage laterally relative to the tape path to position the head carriage at a selected one of multiple tape track positions in accordance with coarse positioning information,

fine positioning means mounted to the coarse positioning means for pivotally securing the magnetic head structure adjacent to the tape path,

the magnetic head structure including optical sensing means for sensing the optically manifested track servo pattern and for producing a position signal, and

a fine position control loop responsive to the position signal for generating and applying a correction signal to the fine positioning means to fine position the magnetic head structure laterally relative to the tape in order to follow particular ones of the data tracks.