Magnetic-disk glass substrate and magnetic disk
US-9564166-B2 · Feb 7, 2017 · US
Magnetic-disk substrate and magnetic disk
US10283156B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-10283156-B2 |
| Application number | US-201715401615-A |
| Country | US |
| Kind code | B2 |
| Filing date | Jan 9, 2017 |
| Priority date | Aug 29, 2012 |
| Publication date | May 7, 2019 |
| Grant date | May 7, 2019 |
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- Title
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Abstract
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A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.
First claim
Opening claim text (preview).
What is claimed is: 1. A magnetic-disk substrate in which an average value of squares of inclinations is 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm, an RMS (Rq) value that is calculated as a roughness in a wavelength bandwidth of 100 μm to 500 μm on the main surface is 0.5 nm or less, and the main surface is configured to receive at least a magnetic recording layer thereon. 2. The magnetic-disk substrate according to claim 1 , wherein the frequency at which squares of inclinations are 0.004 or more is 10% or less. 3. The magnetic-disk substrate according to claim 1 , wherein an arithmetic average roughness of the main surface is 0.15 nm or less. 4. The magnetic-disk substrate according to claim 1 , wherein the magnetic-disk substrate is configured as a substrate of a magnetic disk for energy-assisted magnetic recording. 5. A magnetic disk having at least a magnetic recording layer formed on a main surface of a magnetic-disk substrate in which an average value of squares of inclinations is 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on the main surface are obtained at intervals of 10 nm, and an RMS (Rq) value that is calculated as a roughness in a wavelength bandwidth of 100 μm to 500 μm on the main surface is 0.5 nm or less. 6. The magnetic disk according to claim 5 , wherein the frequency at which squares of inclinations are 0.004 or more is 10% or less. 7. The magnetic disk according to claim 5 , wherein an arithmetic average roughness of the main surface is 0.15 nm or less. 8. The magnetic disk according to claim 5 , wherein the magnetic-disk substrate is configured as a substrate of the magnetic disk for energy-assisted magnetic recording.
Assignees
Inventors
Classifications
- G11B5/7315Primary
Physics · mapped topic
- G11B5/82Primary
Disk carriers · CPC title
Glass or ceramic substrates · CPC title
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Frequently asked questions
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- What does patent US10283156B2 cover?
- A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.
- Who is the assignee on this patent?
- Itaya Masanobu, Osakabe Kinobu, Takizawa Toshio, and 2 more
- What technology area does this patent fall under?
- Primary CPC classification G11B5/7315. Mapped technology areas include Physics.
- When was this patent published?
- Publication date Tue May 07 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 2 related publications on this page (citations in our corpus or others sharing the same primary CPC).