US5202880A — Double-sided magneto-optical media for a multi-di…

Claim 1

Independent Claim 175 words

A magneto-optical disk for use with a lightbeam and an air-bearing low-flying read/write head of a rotary disk device for storing information comprising: a substrate having a microscopic relief formed on a side surface thereof to provide a pre-formatted structure for storing information; a thin-film reflective layer applied on said side surface to reflect an incident lightbean used for reading and writing information; a transparent thin-film dielectric layer applied on said reflective layer to isolate said reflective layer; an optically sensitive thin-film recording layer applied on said dielectric layer, the composition of said recording layer including a rare-earth transition-metal to magnetically store information; and a transparent thin-film protective layer applied on said recording layer, the asperity of the surface of said protective layer being generally not greater than 60% of the predetermined fly height of the air-bearing low-flying read/write head, and the composition of said protective layer having stiction sufficiently weak to allow the read/write head to fly over the disk at said predetermined height during operation of the disk in a rotary disk device.

Claim 2

Dependent Claim 175 words

A magneto-optical disk for use with a lightbeam and an air-bearing low-flying read/write head of a rotary disk device for storing information comprising: a substrate having a microscopic relief formed on a side surface thereof to provide a pre-formatted structure for storing information; a thin-film reflective layer applied on said side surface to reflect an incident lightbean used for reading and writing information; a transparent thin-film dielectric layer applied on said reflective layer to isolate said reflective layer; an optically sensitive thin-film recording layer applied on said dielectric layer, the composition of said recording layer including a rare-earth transition-metal to magnetically store information; and a transparent thin-film protective layer applied on said recording layer, the asperity of the surface of said protective layer being generally not greater than 60% of the predetermined fly height of the air-bearing low-flying read/write head, and the composition of said protective layer having stiction sufficiently weak to allow the read/write head to fly over the disk at said predetermined height during operation of the disk in a rotary disk device.

Claim 3

Dependent Claim 24 words

The disk as in claim 1 wherein said dielectric, recording, and protective thin-film layers are transparent to be compatible with an air incident lightbeam.

Claim 4

Dependent Claim 14 words

The disk as in claim 1 wherein said disk is about 1.2 mm thick.

Claim 5

Dependent Claim 21 words

The disk as in claim 1 wherein said relief includes a plurality of spaced closely concentric grooves or a spiral groove.

Claim 6

Dependent Claim 48 words

The disk as in claim 1 wherein said side surface is partitioned into a first and second annular zone, that portion of said side surface in said first annular zone including said relief, and that portion of said side surface in said second annular zone being substantially flat.

Claim 7

Dependent Claim 12 words

The disk as in claim 1 wherein said substrate is optically opaque.

Claim 8

Dependent Claim 16 words

The disk as in claim 1 wherein said substrate is made of polycarbonate, glass, or aluminum.

Claim 9

Dependent Claim 27 words

The disk as in claim 1 wherein the predetermined fly height of the low-flying air-bearing read/write head is generally in the range of 20 to 80 microinches.

Claim 10

Dependent Claim 24 words

The disk as in claim 1 wherein said protective layer includes silicon nitride for use with a read/write head made of an aluminum-oxide-carbide material.

Claim 11

Dependent Claim 168 words

The disk as in claim 1 further including a microscopic relief formed on a second side surface thereof to provide a pre-formatted structure for storing information; a second thin-film reflective layer applied on said second side surface to reflect an incident lightbeam used for reading and writing information; a second transparent thin-film dielectric layer applied on said second reflective layer to isolate said second reflective layer; an second optically sensitive thin-film recording layer applied on said second dielectric layer, the composition of said second recording layer including a rare-earth transition-metal to magnetically store information; and a second transparent thin-film protective layer applied on said second recording layer, the asperity of the surface of said second protective layer being less than 60% of the predetermined fly height of the air-bearing low-flying read/write head, and the composition of said second protective layer having stiction sufficiently weak to allow the read/write head to fly over the disk at a predetermined height during operation of the disk in a rotary disk device.

Claim 12

Dependent Claim 149 words

A double sided optically sensitive media for a storing information in a high storage density information storage system comprising: a substrate having two side surfaces, each of said side surfaces having a microscopic relief formed on an annular portions thereof; a thin-film reflective layer on each of said side surfaces of said substrate to reflect a lightbeam; a transparent thin-film dielectric layer on each of said reflective layers to isolate said reflective layers; an optically sensitive thin-film recording layers on each of said dielectric layers, the composition of said recording layers including a rare-earth transition-metal to magnetically store information; and a transparent thin-film protective layer on each of said recording layers, the composition of said protective layers having stiction sufficiently weak and asperity sufficiently low to allow a read/write heads to fly over the double sided media at a predetermined low height during operation of the information storage system.

Claim 13

Dependent Claim 149 words

A double sided optically sensitive media for a storing information in a high storage density information storage system comprising: a substrate having two side surfaces, each of said side surfaces having a microscopic relief formed on an annular portions thereof; a thin-film reflective layer on each of said side surfaces of said substrate to reflect a lightbeam; a transparent thin-film dielectric layer on each of said reflective layers to isolate said reflective layers; an optically sensitive thin-film recording layers on each of said dielectric layers, the composition of said recording layers including a rare-earth transition-metal to magnetically store information; and a transparent thin-film protective layer on each of said recording layers, the composition of said protective layers having stiction sufficiently weak and asperity sufficiently low to allow a read/write heads to fly over the double sided media at a predetermined low height during operation of the information storage system.

Claim 14

Dependent Claim 13 words

The media as in claim 11 wherein said protective layer is silicon nitride.

Claim 15

Dependent Claim 20 words

The media as in claim 12 wherein the predetermined fly height of said read/write head is less than 80 microinches.

Claim 16

Dependent Claim 180 words

A high density magneto-optical storage system for storing information comprising: a plurality of disks axially mounted on a rotatable spindle, each of said disks having two side surfaces; a plurality of air-bearing low-flying read/write heads to read and write information on said plurality of disks; each of said disks including a substrate having a microscopic relief formed on each of said side surfaces to provide a pre-formatted structure for storing information; a thin-film reflective layer on each of said side surfaces to reflect a lightbeam used for reading and writing information; a transparent thin-film dielectric layer on each of said reflective layers to isolate said reflective layers; an optically sensitive thin-film recording layer on each of said dielectric layers, the composition of said recording layer including a rare-earth transition-metal to magnetically store information; and a transparent thin-film protective layer on each of said recording layer, the composition of said protective layers having weak stiction and low asperity being effective to allow said read/write heads to fly over said side surfaces of said disks during operation of the information storage system.

Claim 17

Dependent Claim 180 words

A high density magneto-optical storage system for storing information comprising: a plurality of disks axially mounted on a rotatable spindle, each of said disks having two side surfaces; a plurality of air-bearing low-flying read/write heads to read and write information on said plurality of disks; each of said disks including a substrate having a microscopic relief formed on each of said side surfaces to provide a pre-formatted structure for storing information; a thin-film reflective layer on each of said side surfaces to reflect a lightbeam used for reading and writing information; a transparent thin-film dielectric layer on each of said reflective layers to isolate said reflective layers; an optically sensitive thin-film recording layer on each of said dielectric layers, the composition of said recording layer including a rare-earth transition-metal to magnetically store information; and a transparent thin-film protective layer on each of said recording layer, the composition of said protective layers having weak stiction and low asperity being effective to allow said read/write heads to fly over said side surfaces of said disks during operation of the information storage system.

Claim 18

Dependent Claim 28 words

The system as in claim 14 wherein said plurality of disks are spaced apart less than 1 cm and each of said disks is about 1.2 mm thick.

Claim 19

Dependent Claim 14 words

The system as in claim 14 including at least six disks on said spindle.

Claim 20

Dependent Claim 22 words

The system as in claim 14 wherein said light beam is air incident on said side surfaces of said plurality of disks.

Claim 21

Dependent Claim 19 words

The system as in claim 14 wherein the fly height of said read/write heads is less than 80 microinches.

Claim 22

Dependent Claim 22 words

The system as in claim 14 wherein the asperity is substantially less than 60% of the fly height of said read/write heads.

Claim 23

Independent Claim 162 words

A method for making a magneto-optical disk for use with an air-incident lightbeam and an air-bearing low-flying read/write head of a rotary disk device for storing information comprising the steps of: forming a substrate; forming a microscopic relief formed on a side surface of said substrate to provide a pre-formatted structure for storing information; applying a thin-film reflective layer on said side surface to reflect a lightbeam used for reading and writing information; applying a transparent thin-film dielectric layer on said reflective layer to isolate said reflective layer; applying an optically sensitive thin-film recording layer on said dielectric layer, the composition of said recording layer including a rare-earth transition-metal to magnetically store information; and applying a transparent thin-film protective layer applied on said recording layer, the composition of said protective layer having weak stiction and low asperity to allow a read/write head to fly over said side surface at a predetermined height during operation of the disk in a rotary disk device.

Claim 24

Independent Claim 162 words

A method for making a magneto-optical disk for use with an air-incident lightbeam and an air-bearing low-flying read/write head of a rotary disk device for storing information comprising the steps of: forming a substrate; forming a microscopic relief formed on a side surface of said substrate to provide a pre-formatted structure for storing information; applying a thin-film reflective layer on said side surface to reflect a lightbeam used for reading and writing information; applying a transparent thin-film dielectric layer on said reflective layer to isolate said reflective layer; applying an optically sensitive thin-film recording layer on said dielectric layer, the composition of said recording layer including a rare-earth transition-metal to magnetically store information; and applying a transparent thin-film protective layer applied on said recording layer, the composition of said protective layer having weak stiction and low asperity to allow a read/write head to fly over said side surface at a predetermined height during operation of the disk in a rotary disk device.

Claim 25

Dependent Claim 26 words

The method as in claim 20 further including the step of forming said relief as a plurality of spaced closely concentric grooves or a spiral groove.

Claim 26

Dependent Claim 52 words

The method as in claim 20 further including the steps of partitioning said side surface into a first and second annular zone, forming said relief in that portion of said side surface in said first annular zone, and making that portion of said side surface in said second annular zone substantially flat.

Claim 27

Dependent Claim 45 words

The method as in claim 20 further including the step of reducing the asperity and stiction of said side surface to permit an air-bearing low-flying read/write head to fly over said side surface at a height in the range of about 20 to 80 microinches.

Claim 28

Dependent Claim 124 words

A thin-film, double sided, magneto-optical media for storing information by means of an air incident lightbeam comprising: a substrate having two side surfaces, each of said side surfaces having a microscopic relief to provide a pre-formatted structure for storing information; a thin-film reflective layer on each of said side surfaces to reflect an incident lightbeam used for reading and writing information; an optional transparent thin-film dielectric layer on each of said reflective layers to isolate said reflective layers; an optically sensitive thin-film recording layer applied on each of said dielectric layers, the composition of said recording layers including a rare-earth transition-metal to magnetically store information; and a transparent thin-film protective layer on each of said recording layers to minimize corrosion of said recording layers.

Claim 29

Dependent Claim 124 words

A thin-film, double sided, magneto-optical media for storing information by means of an air incident lightbeam comprising: a substrate having two side surfaces, each of said side surfaces having a microscopic relief to provide a pre-formatted structure for storing information; a thin-film reflective layer on each of said side surfaces to reflect an incident lightbeam used for reading and writing information; an optional transparent thin-film dielectric layer on each of said reflective layers to isolate said reflective layers; an optically sensitive thin-film recording layer applied on each of said dielectric layers, the composition of said recording layers including a rare-earth transition-metal to magnetically store information; and a transparent thin-film protective layer on each of said recording layers to minimize corrosion of said recording layers.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1996-04-12	1996-10-12	1997-04-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2000-04-12	2000-10-12	2001-04-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2004-04-12	2004-10-12	2005-04-13	$7700.00	Window Closed / Lapsed

Double-sided magneto-optical media for a multi-disk storage device

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