EP0162349A2
Expired / Lapsed
EP
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A data recording medium
Assignee: International Business Machines Corp
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Filing: 1985-04-30
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Granted: —
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Expires: 2005-04-30
Abstract
Abstract A data recording medium including a structure providing variable electromagnetic property (variable, resistance, capacitive, or other variable impedance or other variable electromagnetic property) contrast on the surface marking servo tracks. Such media include magnetic or optical storage disks and tapes. The media can be conductive metallic or nonmetallic and can be composed for example of poorly conductive media, dielectric media, or semiconductive media. The variable electromagnetic impedance can vary in the optical, electrical or other portions of the electromagnetic spectrum. A very small variation of the thickness of the protective layer above the magnetic recording medium is employed to mark the servo track information of the medium. Information to be detected by means of a capacitive sensor can be recorded in the protective layer above or below the magnetic recording or optical storage medium. For example, a thin film metallic protective layer 0.07 micrometers thick can be patterned with about 0.02 micrometers of the protective layer. For a plated disk, the top 0.02 micrometers of the protective layer can be patterned. A pattern for providing a variable impedance for representing data can be formed subtractively by sputter etching, or additively formed by a lift-off process or by deposition through a mask, or by the oxidation of or nitriding of materials such as Al, Si or valve metals.
Inventors
- 👤 John Steward Best
- 👤 Lubomyr Taras Romankiw
- 👤 Robert Alan Scranton
- 👤 David Allen Thompson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 17:24
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0938; G11B23/00; G11B23/30; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/74; G11B5/82; G11B7/24
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
117 words
A data recording medium for use in a data recording system, said medium being adapted for use with a servo system for following a track on said medium, comprising, a substrate, a data recording layer on said substrate, an additional layer above or below said data recording layer, said additional layer having a patterned variable thickness, said patterned variable thickness representing a variation in electromagnetic properties comprising a servo pattern for use in a variable electromagnetic property track following servo system, with said pattern being present or replicated upon the upper one of said additional layer or said data recording layer, whereby a variation in an electromagnetic property is presented upon the upper surface of said disk.
Claim 2
Dependent Claim
117 words
A data recording medium for use in a data recording system, said medium being adapted for use with a servo system for following a track on said medium, comprising, a substrate, a data recording layer on said substrate, an additional layer above or below said data recording layer, said additional layer having a patterned variable thickness, said patterned variable thickness representing a variation in electromagnetic properties comprising a servo pattern for use in a variable electromagnetic property track following servo system, with said pattern being present or replicated upon the upper one of said additional layer or said data recording layer, whereby a variation in an electromagnetic property is presented upon the upper surface of said disk.
Claim 3
Dependent Claim
21 words
A data recording medium in accordance with claim 1 including a thin protective layer over said upper surface of said medium.
Claim 4
Dependent Claim
16 words
A magnetic recording patterned disk in accordance with claim 1 wherein said patterned material is metallic.
Claim 5
Dependent Claim
20 words
A magnetic recording disk in accordance with claim 1 wherein said magnetic recording layer is a metallic thin film layer.
Claim 6
Dependent Claim
31 words
A magnetic recording patterned disk in accordance with claim 1 wherein said magnetic recording material is a metallic thin film layer and said patterned material is beneath said magnetic recording material.
Claim 7
Dependent Claim
15 words
A magnetic recording disk in accordance with claim 5 wherein said patterned material is metallic.
Claim 8
Dependent Claim
66 words
A magnetic recording disk for use in a magnetic disk file having a track-following servo comprisinga substrate, a magnetic recording layer on said substrate, an additional planar layer above said magnetic recording layer, said additional planar layer being composed of at least two alternating materials with different dielectric constants or resistivities representing a variable impedance servo pattern for use in a variable impedance track-following servo system.
Claim 9
Dependent Claim
66 words
A magnetic recording disk for use in a magnetic disk file having a track-following servo comprisinga substrate, a magnetic recording layer on said substrate, an additional planar layer above said magnetic recording layer, said additional planar layer being composed of at least two alternating materials with different dielectric constants or resistivities representing a variable impedance servo pattern for use in a variable impedance track-following servo system.
Claim 10
Dependent Claim
71 words
8, A magnetic recording medium for use in a magnetic recording system, said medium being adapted for use with a-servo system for following a track on said medium, comprising,a substrate, a magnetic recording layer on said substrate, an additional layer on said magnetic recording layer, said additional layer having a patterned variable thickness, said patterned variable thickness representing a capacitive servo pattern for use in a capacitive track following servo system.
Claim 11
Dependent Claim
71 words
8, A magnetic recording medium for use in a magnetic recording system, said medium being adapted for use with a-servo system for following a track on said medium, comprising,a substrate, a magnetic recording layer on said substrate, an additional layer on said magnetic recording layer, said additional layer having a patterned variable thickness, said patterned variable thickness representing a capacitive servo pattern for use in a capacitive track following servo system.
Claim 12
Dependent Claim
18 words
A magnetic recording disk in accordance with claim 8 including a thin protective layer over said patterned layer.
Claim 13
Dependent Claim
16 words
A magnetic recording patterned disk in accordance with claim 8 wherein said patterned material is metallic.
Claim 14
Dependent Claim
20 words
A magnetic recording disk in accordance with claim 8 wherein said magnetic recording layer is a metallic thin film layer.
Claim 15
Dependent Claim
28 words
A magnetic recording disk in accordance with claim 8 wherein said additional layer comprises aluminum coated with a thin protective layer of aluminum oxide over said patterned layer.
Claim 16
Dependent Claim
26 words
A magnetic recording patterned disk in accordance with claim 8 wherein said patterned material comprises silicon and said layer of silicon is coated with silicon dioxide.
Claim 17
Dependent Claim
28 words
A magnetic recording disk in accordance with claim 8 wherein said additional-layer comprises titanium coated with a thin protective layer of titanium dioxide over said patterned layer. "
Claim 18
Dependent Claim
26 words
A magnetic recording patterned disk in accordance with claim 8 wherein said patterned material comprises chromium and said layer of chromium is coated with chromium dioxide.
Claim 19
Dependent Claim
33 words
A magnetic recording patterned disk in accordance with claim 8 wherein said patterned material comprises a valve metal and said layer of valve metal is coated with the oxide of said valve metal.
Claim 20
Dependent Claim
63 words
A magnetic recording disk for use in a magnetic disk file having a track-following servo comprisinga substrate, a magnetic recording layer on said substrate, an additional planar layer on said magnetic recording layer, said additional planar layer being composed of at least two alternating materials with different permitivities or resistivities representing a capacitive servo pattern for use in a capacitive track-following servo system.
Claim 21
Dependent Claim
63 words
A magnetic recording disk for use in a magnetic disk file having a track-following servo comprisinga substrate, a magnetic recording layer on said substrate, an additional planar layer on said magnetic recording layer, said additional planar layer being composed of at least two alternating materials with different permitivities or resistivities representing a capacitive servo pattern for use in a capacitive track-following servo system.
Claim 22
Dependent Claim
37 words
A magnetic recording disk for use in a magnetic disk file having a magnetic recording medium composed of a metallic material, said medium having on its upper surface a pattern formed or patterned by deposition or etching.
Claim 23
Dependent Claim
37 words
A magnetic recording disk for use in a magnetic disk file having a magnetic recording medium composed of a metallic material, said medium having on its upper surface a pattern formed or patterned by deposition or etching.
Claim 24
Dependent Claim
26 words
A magnetic recording disk in accordance with claim 18 wherein said upper surface is overcoated with a dielectric or metallic material which is also wear resistant.
Claim 25
Dependent Claim
19 words
A magnetic recording disk in accordance with claim 18 wherein said metallic layer is coated with a lubricating layer.
Claim 26
Dependent Claim
19 words
A magnetic recording disk in accordance with claim 19 wherein said metallic layer is coated with a lubricating layer.
Claim 27
Dependent Claim
21 words
A magnetic recording disk in accordance with claim 1 wherein said magnetic recording layer is protected by an etch stop layer.
Claim 28
Dependent Claim
21 words
A magnetic recording disk in accordance with claim 7 wherein said magnetic recording layer is protected by an etch stop layer.
Claim 29
Dependent Claim
25 words
A magnetic recording disk in accordance with claim 8 wherein said magnetic recording layer is protected by an etch stop layer below said additional layer.
Claim 30
Dependent Claim
31 words
A magnetic recording disk in accordance with claim 17 wherein said magnetic recording layer is protected by an.etch stop layer located between said magnetic recording layer and said additional planar layer.
Claim 31
Dependent Claim
26 words
A magnetic recording patterned disk in accordance with claim 8 wherein said patterned material comprises tantalum and said layer of tantalum is coated with tantalum dioxide.
References Cited (Backward Citations)
No citation records indexed.
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