MAGNETIC TAPE DEVICE AND HEAD TRACKING SERVO METHOD
First Claim
1. A magnetic tape device comprising:
- a magnetic tape; and
a servo head,wherein the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element,the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,the magnetic layer includes a servo pattern,a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm,a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, andΔ
SFD in a longitudinal direction of the magnetic tape calculated by Expression 1 is equal to or smaller than 0.50,
Δ
SFD=SFD25°
C.−
SFD−
190°
C.
Expression 1in Expression 1, the SFD25°
C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25°
C., and the SFD−
190°
C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of −
190°
C.
1 Assignment
0 Petitions
Accused Products
Abstract
The magnetic tape device including: a magnetic tape including a servo pattern on a magnetic layer; and a TMR head as a servo head, in which a center line average surface roughness Ra measured regarding a surface of the magnetic layer of the magnetic tape is equal to or smaller than 2.0 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and ΔSFD in a longitudinal direction of the magnetic tape calculated by Expression 1: ΔSFD=SFD25° C.−SFD−190° C. is equal to or smaller than 0.50, wherein the SFD25° C. is SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD−190° C. is SFD measured in a longitudinal direction of the magnetic tape at a temperature of −190° C.
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Citations
18 Claims
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1. A magnetic tape device comprising:
-
a magnetic tape; and a servo head, wherein the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the magnetic layer includes a servo pattern, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and Δ
SFD in a longitudinal direction of the magnetic tape calculated by Expression 1 is equal to or smaller than 0.50,
Δ
SFD=SFD25°
C.−
SFD−
190°
C.
Expression 1in Expression 1, the SFD25°
C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25°
C., and the SFD−
190°
C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of −
190°
C. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A head tracking servo method comprising:
-
reading a servo pattern of a magnetic layer of a magnetic tape by a servo head in a magnetic tape device, wherein the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the magnetic layer includes the servo pattern, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and Δ
SFD in a longitudinal direction of the magnetic tape calculated by Expression 1 is equal to or smaller than 0.50,
Δ
SFD=SFD25°
C.−
SFD−
190°
C.
Expression 1in Expression 1, the SFD25°
C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25°
C., and the SFD−
190°
C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of −
190°
C. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification