Spacer and hard disk drive apparatus

Patent metadata

Field	Value
Publication number	US-11238895-B2
Application number	US-202017111068-A
Country	US
Kind code	B2
Filing date	Dec 3, 2020
Priority date	Aug 31, 2017
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A ring-shaped spacer is to be arranged in contact with a magnetic disk in a hard disk drive apparatus. A maximum height surface roughness Rz of an outer circumferential edge surface of the spacer is at least 1.5 μm, and the spacer is made of amorphous glass.

First claim

What is claimed is:

1. A ring-shaped spacer to be arranged in contact with a magnetic disk in a hard disk drive apparatus,
wherein a maximum height surface roughness Rz of an outer circumferential edge surface of the spacer is at least 1.5 μm,
the spacer is made of amorphous glass, and
a skewness of the outer circumferential edge surface is not larger than 1.2.

2. The spacer according to claim 1 ,
wherein the maximum height surface roughness Rz of the outer circumferential edge surface is not larger than 20 μm.

3. The spacer according to claim 2 ,
wherein the outer circumferential edge surface defines grooves that extend along an outer circumference of the spacer, the grooves contributing to a surface roughness of the outer circumferential edge surface having the maximum height surface roughness Rz.

4. The spacer according to claim 3 ,
wherein a conductive film is formed on a surface of the spacer.

5. The spacer according to claim 2 ,
wherein a conductive film is formed on a surface of the spacer.

6. The spacer according to claim 1 ,
wherein the outer circumferential edge surface defines grooves that extend along an outer circumference of the spacer, the grooves contributing to a surface roughness of the outer circumferential edge surface having the maximum height surface roughness Rz.

7. The spacer according to claim 6 ,
wherein a conductive film is formed on a surface of the spacer.

8. The spacer according to claim 1 ,
wherein a conductive film is formed on a surface of the spacer.

9. A hard disk drive apparatus comprising:
a ring-shaped spacer arranged in contact with a magnetic disk in the hard disk drive apparatus,
wherein a maximum height surface roughness Rz of an outer circumferential edge surface of the spacer is at least 1.5 μm,
the spacer is made of amorphous glass, and
a skewness of the outer circumferential edge surface is not larger than 1.2.

10. The hard disk drive apparatus according to claim 9 ,
wherein eight or more magnetic disks are installed in the hard disk drive apparatus.

11. The hard disk drive according to claim 10 ,
wherein a conductive film is formed on a surface of the spacer.

12. The hard disk drive apparatus according to claim 11 ,
wherein the maximum height surface roughness Rz of the outer circumferential edge surface is not larger than 20 μm.

13. The hard disk drive apparatus according to claim 12 ,
wherein the outer circumferential edge surface defines grooves that extend along an outer circumference of the spacer, the grooves contributing to a surface roughness of the outer circumferential edge surface having the maximum height surface roughness Rz.

14. The hard disk drive apparatus according to claim 10 ,
wherein the maximum height surface roughness Rz of the outer circumferential edge surface is not larger than 20 μm.

15. The hard disk drive apparatus according to claim 11 ,
wherein the outer circumferential edge surface defines grooves that extend along an outer circumference of the spacer, the grooves contributing to a surface roughness of the outer circumferential edge surface having the maximum height surface roughness Rz.

16. The hard disk drive according to claim 9 ,
wherein a conductive film is formed on a surface of the spacer.

17. The hard disk drive apparatus according to claim 16 ,
wherein the maximum height surface roughness Rz of the outer circumferential edge surface is not larger than 20 μm.

18. The hard disk drive apparatus according to claim 17 ,
wherein the outer circumferential edge surface defines grooves that extend along an outer circumference of the spacer, the grooves contributing to a surface roughness of the outer circumferential edge surface having the maximum height surface roughness Rz.

19. The hard disk drive apparatus according to claim 16 ,
wherein the outer circumferential edge surface defines grooves that extend along an outer circumference of the spacer, the grooves contributing to a surface roughness of the outer circumferential edge surface having the maximum height surface roughness Rz.

20. The hard disk drive apparatus according to claim 9 ,
wherein the maximum height surface roughness Rz of the outer circumferential edge surface is not larger than 20 μm.

Assignees

• Hoya Corp

Inventors

• Takano Masao

Classifications

• G11B25/043

  using rotating discs · CPC title

• G11B23/0057 Primary

  Intermediate mediums, i.e. mediums provided with an information structure not specific to the method of reproducing or duplication such as matrixes for mechanical pressing of an information structure (for record carriers with directly readable mechanical information G11B3/685); record carriers having a relief information structure provided with or included in layers not specific for a single reproducing method; apparatus or processes specially adapted for their manufacture · CPC title

• G11B17/038

  Centering or locking of a plurality of discs in a single cartridge · CPC title

• G11B17/021 Primary

  Selecting or spacing of record carriers for introducing the heads · CPC title

• G11B25/04

  using flat record carriers, e.g. disc, card · CPC title