Magnetic disk apparatus having magnetic head with pre-erase gap

Patent 4851933 Issued on July 25, 1989. Estimated Expiration Date:

September 16, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

System for detecting position of a read-write head in seek operation on a disk memory having data servo spectors
Patent #: 4499511
Issued on: 02/12/1985
Inventor: Sugaya

System for detecting the position of a read-write head on a disk recording medium having servo sectors with three or more servo patterns
Patent #: 4631606
Issued on: 12/23/1986
Inventor: Sugaya

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Patent #: 4633337
Issued on: 12/30/1986
Inventor: Horie , et al.

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Patent #: 4636885
Issued on: 01/13/1987
Inventor: Yamada , et al.

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Patent #: 4750060
Issued on: 06/07/1988
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Method for producing an amorphous silicon semiconductor device using a multichamber PECVD apparatus Patent #: 4800174
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Inventors

Application

No. 07/097220 filed on 09/16/1987

US Classes:

360/61, Signal switching360/48, Data in specific format360/66Specifics of biasing or erasing

Examiners

Primary: Canney, Vincent P.

Attorney, Agent or Firm

Oblon, Spivak, McClelland, Maier & Neustadt

International Classes

G11B 27/30 (20060101)
G11B 19/02 (20060101)
G11B 5/55 (20060101)
G11B 5/596 (20060101)

Foreign Application Priority Data

1986-09-30 JP

Abstract

A magnetic disk adapted for use in a magnetic disk apparatus, which has a magnetic head with a pre-erase gap and a read/write gap with a predetermined spacing therebetween, and which uses a sector servo system to position the magnetic head onto a target track of the disk, is divided into a plurality of sectors each having an address field and a data field. A spacing gap having a length corresponding to the spacing between the erase and read/write gaps is formed at the beginning of each of the address and data fields. Servo information is provided at least in the spacing gap of the address field. The magnetic disk apparatus energizes the read/write and erase gaps at different timings, so that the initiation and termination of data erasing are performed prior to the initiation and termination of data writing, respectively.