# US 8,785,009 B2 · Magnetic recording medium having space dots and recording dots alternatively formed in the recording track and method of making the same

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- Number: US 8,785,009 B2
- Document ID: US8785009B2
- Status: Granted
- Kind: B2
- Application number: 12/396,797
- Filed: 2009-03-03
- Published: 2009-09-10
- Granted: 2014-07-22
- Earliest claimed: 2008-03-04
- Assignees: Fujitsu Limited
- Applicants: Hiroto Takeshita
- Inventors: Hiroto Takeshita
- Web page: https://patentgrep.com/patent/US8785009B2

## CPC

- G11B 5/746: {Bit Patterned record carriers, wherein each magnetic isolated data island corresponds to a bit}
- B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
- G11B 5/743: {Patterned record carriers, wherein the magnetic recording layer is patterned into magnetic isolated data islands, e.g. discrete tracks}
- G11B 5/82: Disk carriers
- G11B 5/855: Coating only part of a support with a magnetic layer
- 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)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

A magnetic recording medium includes a plurality of recording tracks magnetically continuous with respect to a recording direction and arranged intermittently in a track width direction, a plurality of recording dots intermittently formed in the recording tracks in the recording direction and a plurality of space dots alternately formed in the recording track with the recording dots in the recording direction and having a magnetic moment per unit area smaller than a magnetic moment per unit area of the recording dots.

## Claims

### Claim 1

A magnetic recording medium, comprising:
a plurality of recording tracks magnetically continuous with respect to a recording direction and arranged intermittently in a track width direction;
a plurality of recording dots intermittently formed in the recording tracks in the recording direction; and
a plurality of space dots alternately formed within the recording tracks with the recording dots in the recording direction, and
where the plurality of space dots alternatively formed with the plurality of recording dots are directly contiguous with said recording dots, and a ratio of a magnetic moment per unit area of the plurality of space dots to a magnetic moment per unit area of the plurality of recording dots is between about 5-30%.

### Claim 2 (depends on 1)

The magnetic recording medium according to claim 1, wherein the recording dots and the space dots have the same film thickness.

### Claim 3 (depends on 1)

The magnetic recording medium according to claim 1, wherein the space dots have a film thickness smaller than a film thickness of the recording dots.

### Claim 4 (depends on 1)

The magnetic recording medium according to claim 1, wherein the space dots have a width in a radial direction larger than a length in a circumferential direction.

### Claim 5 (depends on 1)

The magnetic recording medium according to claim 1, wherein a ratio of the magnetic moment per unit area of the space dots to a magnetic moment per unit area of an element of the recording tracks is set to a predetermined value.

### Claim 6

A method for the manufacture of a magnetic recording medium, comprising:
forming a plurality of recording tracks magnetically continuous with respect to a recording direction and arranged intermittently in a track width direction;
forming a plurality of recording dots intermittently formed in the recording tracks in the recording direction; and
forming a plurality of space dots alternately filling space within the recording tracks with the recording dots in the recording direction, and
where the plurality of space dots alternatively formed with the plurality of recording dots are directly contiguous with said recording dots, and a ratio of a magnetic moment per unit area of the plurality of space dots to a magnetic moment per unit area of the plurality of recording dots is between about 5-30%.