Magnetic-disk glass substrate and magnetic disk
US-2015248910-A1 · Sep 3, 2015 · US
Magnetic-disk glass substrate and magnetic disk
US9564166B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-9564166-B2 |
| Application number | US-201314424261-A |
| Country | US |
| Kind code | B2 |
| Filing date | Jun 28, 2013 |
| Priority date | Aug 29, 2012 |
| Publication date | Feb 7, 2017 |
| Grant date | Feb 7, 2017 |
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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).
The invention claimed is: 1. A magnetic-disk glass 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, and the main surface being configured to receive at least a magnetic recording layer thereon. 2. The magnetic-disk glass 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 glass substrate according to claim 2 , wherein the glass substrate is made of glass having a glass-transition temperature of 650° C. or more. 4. The magnetic-disk glass substrate according to claim 2 , wherein an arithmetic average roughness of the main surface is 0.15 nm or less. 5. A magnetic-disk having at least a magnetic recording layer formed on the main surface of the magnetic-disk glass substrate according to claim 2 . 6. The magnetic-disk glass substrate according to claim 1 , wherein the glass substrate is made of amorphous glass. 7. The magnetic-disk glass substrate according to claim 6 , wherein the glass substrate is made of glass having a glass-transition temperature of 650° C. or more. 8. The magnetic-disk glass substrate according to claim 6 , wherein an arithmetic average roughness of the main surface is 0.15 nm or less. 9. A magnetic-disk having at least a magnetic recording layer formed on the main surface of the magnetic-disk glass substrate according to claim 6 . 10. The magnetic-disk glass substrate according to claim 1 , wherein the glass substrate is made of glass having a glass-transition temperature of 650° C. or more. 11. The magnetic-disk glass substrate according to claim 10 , wherein an arithmetic average roughness of the main surface is 0.15 nm or less. 12. A magnetic-disk having at least a magnetic recording layer formed on the main surface of the magnetic-disk glass substrate according to claim 10 . 13. The magnetic-disk glass substrate according to claim 1 , wherein an arithmetic average roughness of the main surface is 0.15 nm or less. 14. A magnetic disk having at least a magnetic recording layer formed on the main surface of the magnetic-disk glass substrate according to claim 1 . 15. The magnetic-disk glass substrate according to claim 1 , wherein the magnetic-disk glass substrate is configured for use as a magnetic disk having a linear recording density of at least 2000 kbpi. 16. A magnetic-disk having at least a magnetic recording layer formed on the main surface of the magnetic-disk glass substrate according to claim 15 .
Assignees
Inventors
Classifications
- G11B5/82Primary
Disk carriers · CPC title
Physics · mapped topic
Glass or ceramic substrates · CPC title
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Frequently asked questions
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- What does patent US9564166B2 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 G11B5/82. Mapped technology areas include Physics.
- When was this patent published?
- Publication date Tue Feb 07 2017 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 1 related publication on this page (citations in our corpus or others sharing the same primary CPC).