Magnetic tape with characterized servo bands, magnetic tape cartridge, and magnetic tape apparatus
In the probability distribution calculated from TDSage, TDSenv, and TC, the magnetic tape has the probability P fail of equal to or less than 0.2%, in which the absolute value of ΔSB exceeds 0.3 μm. TDSage is a maximum absolute value of a difference between the servo band interval obtained before a predetermined storage and the servo band interval obtained after the storage, TDSenv is a value calculated by multiplying a difference between a maximum value and a minimum value of the servo band interval respectively obtained under five predetermined environments by ½, TC is a value calculated by multiplying TDStens by 0.5 N, and TDStens is a ratio of a change in the servo band interval to a change in tension calculated from the servo band interval respectively obtained under five predetermined environments by applying a plurality of different tensions in the longitudinal direction of the magnetic tape.
1. A magnetic tape comprising:
a non-magnetic support; and
a magnetic layer containing a ferromagnetic powder,
wherein the magnetic layer has a plurality of servo bands,
in a probability distribution PD ΔSB of a difference ΔSB of servo band intervals calculated from TDSage, TDSenv, and TC, a probability P fail in which an absolute value of ΔSB exceeds 0.3 μm is equal to or less than 0.2%,
TDSage is a maximum absolute value of a difference between a servo band interval obtained before storage for 24 hours in an environment with a temperature of 60° C. and a relative humidity of 20% and a servo band interval obtained after the storage,
where a unit of TDSage is μm,
TDSenv is a value calculated by multiplying a difference between a maximum value and a minimum value by ½ in servo band intervals obtained respectively in the following five environments;
a temperature of 16° C. and a relative humidity of 20%,
a temperature of 16° C. and a relative humidity of 80%,
a temperature of 26° C. and a relative humidity of 80%,
a temperature of 32° C. and a relative humidity of 20%, and
a temperature of 32° C. and a relative humidity of 55%,
where a unit of TDSenv is μm,
TC is a value calculated by multiplying TDStens by 0.5 N, and
TDStens is a ratio of a change in a servo band interval to a change in tension, which is calculated from servo band intervals obtained by applying a plurality of different tensions in a longitudinal direction of the magnetic tape and obtained respectively in the following five environments;
a temperature 16° C. and a relative humidity 20%,
a temperature 16° C. and a relative humidity 80%,
a temperature 26° C. and a relative humidity 80%,
a temperature 32° C. and a relative humidity 20%, and
a temperature 32° C. and a relative humidity 55%
where a unit of TDStens is μm/N.
2. The magnetic tape according to claim 1 ,
wherein the probability P fail is equal to or less than 0.1%.
3. The magnetic tape according to claim 1 ,
wherein a tape thickness is equal to or less than 5.6 μm.
4. The magnetic tape according to claim 1 ,
wherein a tape thickness is equal to or less than 5.3 μm.
5. The magnetic tape according to claim 1 ,
wherein a non-magnetic layer containing a non-magnetic powder is provided between the non-magnetic support and the magnetic layer.
6. The magnetic tape according to claim 1 ,
wherein a back coating layer containing a non-magnetic powder is provided on a surface side of the non-magnetic support opposite to a surface side having the magnetic layer.
7. The magnetic tape according to claim 1 ,
wherein the non-magnetic support is an aromatic polyester support.
8. The magnetic tape according to claim 7 ,
wherein the aromatic polyester support is a polyethylene terephthalate support.
9. The magnetic tape according to claim 7 ,
wherein the aromatic polyester support is a polyethylene naphthalate support.
10. A magnetic tape cartridge comprising the magnetic tape according to claim 1 .
11. The magnetic tape cartridge according to claim 10 ,
wherein the probability P fail is equal to or less than 0.1%.
12. The magnetic tape cartridge according to claim 10 ,
wherein a tape thickness of the magnetic tape is equal to or less than 5.6 μm.
13. The magnetic tape cartridge according to claim 10 ,
wherein a tape thickness of the magnetic tape is equal to or less than 5.3 μm.
14. The magnetic tape cartridge according to claim 10 ,
wherein the non-magnetic support of the magnetic tape is an aromatic polyester support.
15. The magnetic tape cartridge according to claim 14 ,
wherein the aromatic polyester support is a polyethylene terephthalate support.
16. The magnetic tape cartridge according to claim 14 ,
wherein the aromatic polyester support is a polyethylene naphthalate support.
17. A magnetic tape apparatus comprising the magnetic tape cartridge according to claim 10 .
18. The magnetic tape apparatus according to claim 17 ,
wherein in a case where the magnetic tape runs in the magnetic tape apparatus, a tension applied in the longitudinal direction of the magnetic tape is variably adjusted.
19. The magnetic tape apparatus according to claim 18 ,
wherein the tension is adjusted in a range of 0.2 N to 1.2 N.
20. The magnetic tape apparatus according to claim 17 , further comprising:
a magnetic head having a reproducing element having a reproducing element width of 0.8 μm or less.