# US 8,786,969 B2 · Shingled recording systems using multiple pass write, single pass read architecture

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- Number: US 8,786,969 B2
- Document ID: US8786969B2
- Status: Granted
- Kind: B2
- Application number: 13/251,031
- Filed: 2011-09-30
- Published: 2013-04-04
- Granted: 2014-07-22
- Earliest claimed: 2011-09-30
- Assignees: HGST Netherlands B.V.
- Applicants: Prakash Kasiraj; Thomas R. Albrecht
- Inventors: Prakash Kasiraj; Thomas R. Albrecht
- Web page: https://patentgrep.com/patent/US8786969B2

## CPC

- G11B 5/012: Recording on, or reproducing or erasing from, magnetic disks (G11B17/00, G11B19/00 take precedence)
- G11B 5/746: {Bit Patterned record carriers, wherein each magnetic isolated data island corresponds to a bit}
- 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

In one embodiment, a magnetic data storage system includes a bit patterned magnetic medium, wherein centers of bits in adjacent data tracks do not lie on a common line in a cross-track direction, a magnetic head having a writer element having a width greater than a width of a data track in a track width direction adapted for writing data successively to at least two adjacent data tracks of the magnetic medium, and a reader element having a width larger than the width of a data track in the track width direction adapted for reading data concurrently from the at least two adjacent data tracks of the magnetic medium in a single pass, a drive mechanism for passing the magnetic medium over the magnetic head, and a controller electrically coupled to the magnetic head for controlling operation of the magnetic head.

## Claims

### Claim 1

A magnetic data storage system, comprising:
a magnetic head, comprising:
a writer element configured to write data successively to at least two adjacent data tracks of a magnetic medium prior to being read from the magnetic medium, wherein the writer element has a width greater than a width of one data track of the magnetic medium in a track width direction, wherein the at least two adjacent data tracks comprise bits that are arranged in a staggered orientation such that centers of any two bits from the at least two adjacent data tracks do not lie along a common line in a cross-track direction, wherein the data is split into a first group and a second group prior to writing, and wherein the writer element writes data to the staggered bits across the at least two adjacent data tracks in an alternating fashion by writing the first group data to a first data track in a first pass and writing the second group data to a second data track in a second pass, the first data track being adjacent the second data track; and
a reader element configured to read data concurrently from the at least two adjacent data tracks of the magnetic medium in a single pass, wherein the reader element has a width larger than the width of one data track in the track width direction; and
a controller electrically coupled to the magnetic head for controlling operation of the magnetic head, the controller being configured to cause the writer element to write data successively to at least two adjacent data tracks of the magnetic medium by writing a first group of the data to a first data track in a first pass and writing a second group of the data to a second data track in a second pass,
wherein the first data track is adjacent the second data track, and wherein none of the first group of the data lies on a common line in a cross-track direction with any of the second group of the data.

### Claim 2 (depends on 1)

The magnetic data storage system as recited in claim 1, wherein the width of the writer element is at least about a width of two adjacent data tracks in the track width direction.

### Claim 3 (depends on 1)

The magnetic data storage system as recited in claim 1, further comprising:
the magnetic medium; and
a drive mechanism for passing the magnetic medium over the magnetic head.

### Claim 4 (depends on 3)

The magnetic data storage system as recited in claim 3, wherein the controller is configured to logically split the data into at least two groups to be written to the at least two adjacent data tracks based on at least one of: an order of writing the data to the at least two adjacent data tracks, and an order of reading the data from the at least two adjacent data tracks.

### Claim 5

A magnetic data storage system, comprising:
a bit patterned magnetic medium, wherein centers of bits in adjacent data tracks do not lie on a common line in a cross-track direction;
at least one magnetic head, comprising:
a writer element configured to write data successively to at least two adjacent data tracks of the magnetic medium by writing a first group of the data to a first data track in a first pass and writing a second group of the data to a second data track in a second pass, wherein the first data track is adjacent the second data track, and wherein none of the first group of the data lies on a common line in a cross-track direction with any of the second group of the data, wherein the writer element has a width greater than a width of a data track in a track width direction; and
a reader element configured to read data concurrently from the at least two adjacent data tracks of the magnetic medium in a single pass, wherein the reader element has a width larger than the width of a data track in the track width direction;
a drive mechanism for passing the magnetic medium over the at least one magnetic head; and
a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head, the controller being configured to cause the writer element to write data successively to at least two adjacent data tracks of the magnetic medium by writing a first group of the data to a first data track in a first pass and writing a second group of the data to a second data track in a second pass,
wherein the first data track is adjacent the second data track,
wherein none of the first group of the data lies on a common line in a cross-track direction with any of the second group of the data, and
wherein the data is written successively to the adjacent data tracks using shingled magnetic recording.

### Claim 6 (depends on 5)

The magnetic data storage system as recited in claim 5, wherein the controller is configured to logically split data to be written to the magnetic medium into at least two groups to be written to the at least two adjacent data tracks based on at least one of: an order of writing the data to the at least two adjacent data tracks, and an order of reading the data from the at least two adjacent data tracks.

### Claim 7 (depends on 5)

The magnetic data storage system as recited in claim 5, wherein the controller is configured to organize data to be written to the magnetic medium such that the data is written successively to the at least two adjacent tracks of the magnetic medium and read from the at least two adjacent data tracks of the magnetic medium in a single pass.

### Claim 8 (depends on 5)

The magnetic data storage system as recited in claim 5, wherein the writer element overlaps a second data track while writing a first data track, wherein the first data track is adjacent the second data track.

### Claim 9 (depends on 8)

The magnetic data storage system as recited in claim 8, wherein the writer element overlaps a third data track while writing the second data track, wherein the second data track is adjacent the third data track.

### Claim 10 (depends on 5)

The magnetic data storage system as recited in claim 5, wherein the reader element is positioned above the at least two adjacent data tracks while reading the at least two adjacent data tracks concurrently.

### Claim 11 (depends on 5)

The magnetic data storage system as recited in claim 5, wherein the magnetic data storage system employs shingled magnetic recording to store data.

### Claim 12

A method, comprising:
receiving data to be written to a magnetic medium, wherein adjacent track bits in the magnetic medium are arranged in a staggered orientation such that any two centers of the adjacent track bits do not lie along a common line in a cross-track direction;
organizing the data to be written successively to adjacent data tracks of the magnetic medium such that the data is reproducible when read back from the adjacent data tracks concurrently, wherein organizing the data comprises splitting the data into a first group and a second group; and
writing the data successively to the adjacent data tracks, wherein the data is written such that data in adjacent data tracks is staggered, and wherein writing the data comprises:
writing the first group data to a first data track in a first pass; and
writing the second group data to a second data track in a second pass, wherein the first data track is adjacent the second data track, and wherein none of the first group data lies on a common line in a cross-track direction with any of the second group data.

### Claim 13 (depends on 12)

The method as recited in claim 12, wherein organizing the data further comprises splitting the data into a third group, wherein writing the data further comprises writing the third group data to a third data track in a third pass, and wherein the third track is adjacent the second track.

### Claim 14 (depends on 12)

The method as recited in claim 12, further comprising overlapping a writer element with the second data track while writing the first data track.

### Claim 15 (depends on 14)

The method as recited in claim 14, further comprising overlapping the writer element with a third data track while writing the second data track, wherein the third data track is adjacent the second data track opposite the first data track.

### Claim 16 (depends on 12)

The method as recited in claim 12, further comprising reading the first group data from the first data track and the second group data from the second data track in a single pass.

### Claim 17 (depends on 16)

The method as recited in claim 16, wherein the reading is performed using a sensor element of a magnetic head, and wherein a width of the sensor element is at least about a width of two data tracks in a track width direction.

### Claim 18 (depends on 17)

The method as recited in claim 17, wherein the sensor element is positioned above the first and second data tracks while reading the first and second data tracks.

### Claim 19 (depends on 12)

The method as recited in claim 12, further comprising reading the data from the adjacent data tracks concurrently in a single pass.

### Claim 20 (depends on 12)

The method as recited in claim 12, wherein the writing is performed using a writer element of a magnetic head, and wherein a width of the writer element is greater than a width of a data track in a track width direction.

### Claim 21 (depends on 20)

The method as recited in claim 20, wherein the width of the writer element is at least about a width of two data tracks in a track width direction.

### Claim 22 (depends on 12)

The method as recited in claim 12, wherein organizing the data comprises logically splitting the data into at least two groups to be written to at least two adjacent data tracks based on at least one of: an order of writing the data to the at least two adjacent data tracks and an order of reading the data from the at least two adjacent data tracks.

### Claim 23 (depends on 12)

The method as recited in claim 12, wherein the data is written successively to the adjacent data tracks using shingled magnetic recording.

### Claim 24 (depends on 12)

The method as recited in claim 12, wherein the magnetic medium is bit patterned.