# US 10,872,635 B2 · Spacer and hard disk drive apparatus

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- Number: US 10,872,635 B2
- Document ID: US10872635B2
- Status: Granted
- Kind: B2
- Application number: 16/634,079
- Filed: 2018-08-31
- Published: 2020-07-23
- Granted: 2020-12-22
- Earliest claimed: 2017-08-31
- Assignees: Hoya Corporation
- Applicants: Hoya Corporation
- Inventors: Masao Takano
- Web page: https://patentgrep.com/patent/US10872635B2

## CPC

- G11B 17/021: {Selecting or spacing of record carriers for introducing the heads}
- G11B 17/028: of discs rotating during transducing operation
- G11B 17/038: Centering or locking of a plurality of discs in a single cartridge
- G11B 25/04: using flat record carriers, e.g. disc, card
- G11B 25/043: {using rotating discs}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

When removing magnetic disks and spacers from a hard disk drive apparatus, as necessary, during the assembly of the hard disk drive apparatus, in order to suppress the occurrence of removal failures when removing the spacers using a gripping jig, a surface roughness Rz of an outer circumferential edge surface of a spacer is set to be at least 1.5 μm.

## Claims

### Claim 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, and
a skewness of the outer circumferential edge surface is not larger than 1.2.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 2)

The spacer according to claim 2,
wherein the outer circumferential edge surface define 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.

### Claim 4 (depends on 2)

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

### Claim 5 (depends on 2)

The spacer according to claim 2,
wherein the spacer is made of glass.

### Claim 6 (depends on 1)

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.

### Claim 7 (depends on 6)

The spacer according to claim 6,
wherein the spacer is made of glass.

### Claim 8 (depends on 6)

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

### Claim 9 (depends on 1)

The spacer according to claim 1,
wherein the spacer is made of glass.

### Claim 10 (depends on 9)

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

### Claim 11 (depends on 1)

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

### Claim 12

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, and
a skewness of the outer circumferential edge surface is not larger than 1.2.

### Claim 13 (depends on 12)

The hard disk drive apparatus according to claim 12,
wherein eight or more magnetic disks are installed in the hard disk drive apparatus.

### Claim 14 (depends on 13)

The hard disk drive apparatus according to claim 13,
wherein the maximum height surface roughness Rz of the outer circumferential edge surface is not larger than 20 μm.

### Claim 15 (depends on 13)

The hard disk drive apparatus according to claim 13,
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.

### Claim 16 (depends on 13)

The hard disk drive apparatus according to claim 13,
wherein the spacer is made of glass.

### Claim 17 (depends on 13)

The hard disk drive apparatus according to claim 13,
wherein a conductive film is formed on a surface of the spacer.

### Claim 18 (depends on 17)

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

### Claim 19 (depends on 17)

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.

### Claim 20 (depends on 17)

The hard disk drive apparatus according to claim 17,
wherein the spacer is made of glass.