Method for forming a servo pattern on a magnetic tape
The systems, methods and products of the invention include systems and methods for manufacturing servo tracks on a magnetic tape. In one aspect, the invention includes systems for manufacturing magnetic tapes having servo tracks thereon wherein the servo tracks are optically detectable and are capable of being processed by a servo control system for maintaining alignment of a magnetic recording head with the data tracks on the recording side of the magnetic tape. In one practice, the manufacturing systems described herein engrave the servo tracks onto the non-recording side of a magnetic tape by directing a laser beam at the non-recording side of the magnetic tape. In another practice, the manufacturing systems described herein engrave the servo tracks onto the magnetic side of a magnetic tape by directing a laser beam at the magnetic side of the magnetic tape. Such engraved patterns can act as optical servo tracks for maintaining alignment of the recording head with the data tracks on the magnetic tape.
1. A method for producing, on a magnetic tape having a magnetic recording side and a non-recording side opposite the recording side, a plurality of servo tracks capable of being optically detected independently from one another, the method comprising
passing at least a portion of the magnetic tape through a work area; and
forming the servo tracks and non-servo tracks on a surface of the non-recording side of the portion of the magnetic tape as the tape passes through the work area, the servo tracks being grouped in bands, each comprised of two or more servo tracks, each of the bands being delimited by at least one non-servo track at upper and lower portions thereof, each of the bands corresponding to a data track on the magnetic recording side, the bands being separated from one another by a first distance and servo tracks in the bands being separated from one another by a second distance, the first distance being greater than the second distance.
2. The method according to claim 1 , wherein each of the servo tracks comprises a plurality of discrete optically independently detectable longitudinally spaced marks.
3. The method according to claim 2 wherein forming comprises forming servo marks on different servo tracks, and wherein the servo marks that are located on the different servo tracks are formed simultaneously.
4. The method according to claim 1 , wherein forming comprises printing the servo tracks and wherein printing is performed by inkjet printing.
5. The method according to claim 4 wherein the ink-jet printing uses a fluorescent material that is optically detectable under selected lighting conditions.
6. The method according to claim 1 , wherein forming comprises metallizing the tape to form a servo pattern thereon.
7. The method according to claim 1 , wherein forming comprises employing a photographic process to develop an image representative of a servo track pattern.
8. The method according to claim 1 , wherein forming comprises applying a fluorescent material to the magnetic tape.
9. The method according to claim 1 , further comprising burnishing the magnetic tape.
10. The method according to claim 1 , wherein the servo tracks are formed using a plurality of optical beams, and the plurality of optical beams are formed by optically beam-splitting a single laser beam emitted by a laser.
11. The method according to claim 10 , wherein forming the servo tracks comprises
passing the single laser beam through a first beamsplitter to form a first band pattern defining spaced apart multiple bands; and
passing the spaced apart multiple bands through a second beam splitter to form a second band pattern defining servo tracks within a respective one of the spaced apart multiple bands.
12. The method according to claim 1 , further comprising cleaning the magnetic tape after forming the servo tracks on the magnetic tape.
13. The method according to claim 12 , wherein cleaning the magnetic tape includes flowing a gas across a surface of the tape to remove debris from the tape.
14. The method according to claim 12 , wherein cleaning the magnetic tape includes contacting the magnetic tape with a cleaning material to remove debris from the magnetic tape.
15. The method according to claim 1 , further comprising optically verifying a characteristic of the servo tracks to control a marking quality of the servo tracks.
16. The method according to claim 15 , wherein verifying a characteristic includes measuring a characteristic representative of size of a servo track.
17. The method according to claim 15 , wherein verifying a characteristic includes measuring a characteristic representative of location of a servo track.
18. The method according to claim 1 , wherein forming comprises applying an embossing roller to the magnetic tape to form a servo pattern thereon.
19. The method according to claim 1 , wherein a force generated by a linear tape motion urges the recording side of the magnetic tape against a first surface disposed in the work area so as to maintain a focus of the non-recording side of the tape with respect to forming a servo pattern.
20. The method according to claim 19 , wherein a second flat surface substantially perpendicular to the first surface guides a portion of tape passing through the work area to stabilize the tape by reducing transverse motion of the tape.
21. The method according to claim 1 , wherein the servo tracks are formed using a optical beam pattern, and the optical beam pattern has a width that is substantially identical to a width of the magnetic tape.