Magnetic tape and method of manufacturing the same
US-2016093323-A1 · Mar 31, 2016 · US
Magnetic tape device and head tracking servo method
US10438622B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-10438622-B2 |
| Application number | US-201816044574-A |
| Country | US |
| Kind code | B2 |
| Filing date | Jul 25, 2018 |
| Priority date | Feb 20, 2017 |
| Publication date | Oct 8, 2019 |
| Grant date | Oct 8, 2019 |
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Abstract
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The magnetic tape device includes a magnetic tape; and a servo head, in which the servo head is a TMR head, the magnetic tape includes a servo pattern in the magnetic layer, 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 a ratio (Sdc/Sac) of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster thereof in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30.
First claim
Opening claim text (preview).
What is claimed is: 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, and a ratio Sdc/Sac of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster of the magnetic tape in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30. 2. The magnetic tape device according to claim 1 , wherein the center line average surface roughness Ra measured regarding the surface of the magnetic layer is 1.2 nm to 2.0 nm. 3. The magnetic tape device according to claim 1 , wherein the magnetic tape includes a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer. 4. 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, and a ratio Sdc/Sac of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster of the magnetic tape in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30. 5. The head tracking servo method according to claim 4 , wherein the center line average surface roughness Ra measured regarding the surface of the magnetic layer is 1.2 nm to 2.0 nm. 6. The head tracking servo method according to claim 4 , wherein the magnetic tape includes a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.
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- What does patent US10438622B2 cover?
- The magnetic tape device includes a magnetic tape; and a servo head, in which the servo head is a TMR head, the magnetic tape includes a servo pattern in the magnetic layer, 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 s…
- Who is the assignee on this patent?
- Fujifilm Corp
- What technology area does this patent fall under?
- Primary CPC classification G11B5/702. Mapped technology areas include Physics.
- When was this patent published?
- Publication date Tue Oct 08 2019 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 12 related publications on this page (citations in our corpus or others sharing the same primary CPC).