Claims
- 1. Apparatus for servo positioning in a disk file comprising:at least one disk mounted for rotation about an axis and having at least one disk surface for storing data; transducer means mounted for movement across said disk surface for writing to and for reading data and servo patterns from said disk surface; said transducer means including a read element and a write element, said read element having a width less than said write element and said read element being greater than ⅓ of the width of a data cylinder and less than ½ the width of the data cylinder; and a servo pattern written on said data disk surface having a non-zero track pitch of less than ½ of the width of a data cylinder and said servo pattern repeating in a selected number of data cylinders; said selected number being a value equal to a positive power of two.
- 2. Apparatus for servo positioning as recited in claim 1 wherein said servo pattern includes a phase modulated servo pattern.
- 3. Apparatus for servo positioning as recited in claim 1 wherein said servo pattern includes a servo pattern having a ⅓ track pitch and said servo pattern repeating in 4 data cylinders.
- 4. Apparatus for servo positioning as recited in claim 1 wherein said servo pattern is a 5 MHz pattern of 12-bit words.
- 5. Apparatus for servo positioning as recited in claim 1 wherein said servo pattern includes a servo pattern having a ⅓ track pitch and said servo pattern repeating in 2 data cylinders, wherein said servo pattern is a 5 MHz pattern of 6-bit words.
- 6. A direct access storage device comprising:at least one disk mounted in said housing for rotation about an axis and having at least one disk surface for storing data; magneto-resistive (MR) transducer means mounted for movement across said disk surface for writing to and for reading data and servo patterns from said disk surface; said MR transducer means including a write element and a read element, said read element having a width less than said write element and said read element width being greater than ⅓ of the width of a data cylinder and less than ½ of the width of a data cylinder; and a phase modulated servo pattern written on said disk surface at a predetermined non-zero track pitch of less than ½ of the width of a data cylinder and said servo pattern including a phase burst difference between adjacent bursts to go through 360 degrees in a predetermined number of data cylinders, said predetermined number being a value equal to a positive power of two, said predetermined non-zero track pitch defining centerlines of adjacent bursts of said phase modulated servo pattern.
- 7. A direct access storage device as recited in claim 6 wherein said predetermined track pitch equals ⅓ and said predetermined binary number of data cylinders equals 4.
Parent Case Info
This application is a continuation of application Ser. No. 08/194,235 Feb. 10, 1994, now abandoned.
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0129708 |
Jan 1985 |
EP |
Non-Patent Literature Citations (1)
Entry |
Search Report—GB9501719.0. |
Continuations (1)
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Number |
Date |
Country |
Parent |
08/194235 |
Feb 1994 |
US |
Child |
08/632639 |
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US |