# US 8,786,971 B2 · Magnetic recording apparatus having variable-width tracks and method of testing same

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- Number: US 8,786,971 B2
- Document ID: US8786971B2
- Status: Granted
- Kind: B2
- Application number: 14/175,178
- Filed: 2014-02-07
- Published: 2014-06-05
- Granted: 2014-07-22
- Earliest claimed: 2010-06-30
- Assignees: Kabushiki Kaisha Toshiba
- Applicants: Kabushiki Kaisha Toshiba
- Inventors: Masatoshi Sakurai; Kazuto Kashiwagi; Naoki Tagami
- Web page: https://patentgrep.com/patent/US8786971B2

## CPC

- G11B 20/1816: {Testing}
- B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
- G11B 5/455: Arrangements for functional testing of heads; Measuring arrangements for heads
- G11B 5/6011: {Control of flying height}
- G11B 5/746: {Bit Patterned record carriers, wherein each magnetic isolated data island corresponds to a bit}
- G11B 19/048: {Testing of disk drives, e.g. to detect defects or prevent sudden failure}
- G11B 27/36: Monitoring, i.e. supervising the progress of recording or reproducing {(for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06)}
- 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

According to one embodiment, there is provided a magnetic recording apparatus including a head slider including read and write elements, and a magnetic recording medium including magnetically recordable recording tracks with a width L1, a wide land track with a width L2 larger than the width L1 of the recording track, and non-recording sections with a width G1 each provided between adjacent recording tracks. The width L1 of the recording track is smaller than a bottom read width BRW of the read and write elements, and the width L2 of the wide land track is larger than the bottom read width BRW of the read and write elements.

## Claims

### Claim 1

A magnetic recording apparatus comprising:
a head slider comprising read and write elements; and
a magnetic recording medium comprising:
a plurality of magnetically recordable recording tracks comprising a magnetic land width L1,
a wide land track having a magnetic land width L2 larger than L1,
a plurality of first non-recording sections comprising a width G1, each of the plurality of first non-recording sections provided between adjacent recording tracks, and
a second non-recording section comprising a width G2 larger than the width G1 of the first non-recording sections,
wherein the magnetic land width L1 of the recording track is smaller than a bottom read width BRW of the read and write elements, the magnetic land width L2 of the wide land track is larger than the bottom read width BRW of the read and write elements, the wide land track and the second non-recording section are provided in a sweep width of the head slider, and the BRW is an actual value of width between positions at which a signal intensity rises spanning both sides of a signal intensity profile of the read element.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the second non-recording section is adjacent to the wide land track.

### Claim 3 (depends on 1)

A method of testing the magnetic recording apparatus of claim 1, comprising:
performing a test using the wide land track, the test being selected from the group consisting of a test for a flying height of the head slider, a test for a voltage and a current of the read and write elements, and a signal degradation test.

### Claim 4 (depends on 1)

A method of testing the magnetic recording apparatus of claim 1, comprising:
performing a test for magnetic characteristics of the first non-recording sections using the second non-recording section.

### Claim 5 (depends on 1)

The apparatus of claim 1, wherein the first and second non-recording sections are formed by removing or modifying those portions of the magnetic recording layer between the recording tracks or between the recording track and the wide land track.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the magnetic recording medium is a discrete track recording medium.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein the wide land is primarily used for testing the medium.