US5272684A — Information recording method and information reco…

Claim 1

Independent Claim 201 words

An information recording method for a magneto-optic recording information medium comprising the steps of: providing on the magneto-optic recording information medium a track having a land portion, said land portion for carrying the two kinds of information, and said land portion having edges defining groove portions elongated on both sides of said land portion, the edges defining a track land width and the land portion having a track center midway between the edges; overwriting two kinds of information corresponding to two kinds of light beams of different intensities by projecting onto the track the two kinds of light beams so as to have known beam widths and a maximum position error between a beam center and the track center such that the width of a portion of the kind of light beam having lower intensity which exceeds a predetermined intensity above which a mark is formed on the track is greater than the track land width by at least the maximum position error; and providing the magneto-optic recording information medium with a plurality of laminated magnetic layers with vertical magnetic anisotropy, one layer among which keeps its direction of magnetization constant and does not cause flux reversal at recording and reproducing.

Claim 2

Dependent Claim 201 words

An information recording method for a magneto-optic recording information medium comprising the steps of: providing on the magneto-optic recording information medium a track having a land portion, said land portion for carrying the two kinds of information, and said land portion having edges defining groove portions elongated on both sides of said land portion, the edges defining a track land width and the land portion having a track center midway between the edges; overwriting two kinds of information corresponding to two kinds of light beams of different intensities by projecting onto the track the two kinds of light beams so as to have known beam widths and a maximum position error between a beam center and the track center such that the width of a portion of the kind of light beam having lower intensity which exceeds a predetermined intensity above which a mark is formed on the track is greater than the track land width by at least the maximum position error; and providing the magneto-optic recording information medium with a plurality of laminated magnetic layers with vertical magnetic anisotropy, one layer among which keeps its direction of magnetization constant and does not cause flux reversal at recording and reproducing.

Claim 3

Dependent Claim 24 words

An information recording method for a magneto-optic recording information medium as set forth in claim 1, wherein said light beam is a laser beam.

Claim 4

Dependent Claim 27 words

An information recording method for a magneto-optic recording information medium as set forth in claim 1, wherein said magneto-optic recording information medium has four laminated magnetic layers.

Claim 5

Dependent Claim 73 words

An information recording method for a magneto-optic recording information medium as set forth in claim 1, wherein said magneto-optic recording information medium is formed with lamination of ______________________________________ dielectric layer SiNx 65 nm, magnetic layer Tb.sub.22 Fe.sub.69 Co.sub.9 80 nm, magnetic layer Gd.sub.8 Dy.sub.17 Fe.sub.60 Co.sub.15 150 nm, magnetic layer Tb.sub.30 Fe.sub.84 20 nm, magnetic layer Tb.sub.30 Co.sub.70 40 nm, and protective layer SiNx 70 nm ______________________________________ on a substrate in that order.

Claim 6

Dependent Claim 210 words

An information recording method for a magneto-optic information recording medium having at least one recording track defined by a land portion bounded by elongated groove portions along both sides of the land portion and having a track center, the method comprising the steps of: projecting onto the track a first light beam having a first intensity, such that a mark corresponding to the first intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the first intensity being formed in at least one magnetic layer of a plurality of vertically anisotropic magnetic layers disposed thereon; and projecting a second light beam, with a center disposed at a positional offset with respect to the track center less than a known maximum, onto the track, the second light beam having a second intensity, and the second intensity being less than the first intensity, the second light intensity selected such that a mark corresponding to the second intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the second intensity being formed in the at least one magnetic layer.

Claim 7

Dependent Claim 210 words

An information recording method for a magneto-optic information recording medium having at least one recording track defined by a land portion bounded by elongated groove portions along both sides of the land portion and having a track center, the method comprising the steps of: projecting onto the track a first light beam having a first intensity, such that a mark corresponding to the first intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the first intensity being formed in at least one magnetic layer of a plurality of vertically anisotropic magnetic layers disposed thereon; and projecting a second light beam, with a center disposed at a positional offset with respect to the track center less than a known maximum, onto the track, the second light beam having a second intensity, and the second intensity being less than the first intensity, the second light intensity selected such that a mark corresponding to the second intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the second intensity being formed in the at least one magnetic layer.

Claim 8

Dependent Claim 15 words

The method of claim 5, wherein the first and second light beams are laser beams.

Claim 9

Dependent Claim 17 words

The method of claim 5, wherein the plurality of vertically anisotropic magnetic layers includes four magnetic layers.

Claim 10

Dependent Claim 62 words

The method of claim 5, wherein the magneto-optic information recording medium is formed of a lamination of ______________________________________ dielectric layer SiN.sub.x 65 nm magnetic layer Tb.sub.22 Fe.sub.69 Co.sub.9 80 nm magnetic layer Gd.sub.8 Dy.sub.17 Fe.sub.60 Co.sub.15 150 nm magnetic layer Tb.sub.30 Fe.sub.84 20 nm magnetic layer Tb.sub.30 Co.sub.70 40 nm protective layer SiN.sub.x 70 nm ______________________________________ on a substrate in that order.

Claim 11

Dependent Claim 184 words

An information recording method for a magneto-optic information recording medium having at least one recording track defined by a land portion bounded by elongated groove portions along both sides of the land portion and having a track center, the method comprising, in any order, the steps of: projecting onto the track a first light beam having a first intensity, such that a mark corresponding to the first intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the first intensity being formed in at least one magnetic layer of a plurality of vertically anisotropic magnetic layers disposed thereon; and projecting a second light beam, with a center disposed at a positional offset with respect to the track center less than a known maximum, onto the track, the second light beam having a second intensity, such that a mark is formed which extends at least to the elongated groove portions along both sides of the land portion, the mark being formed in the at least one magnetic layer.

Claim 12

Dependent Claim 184 words

An information recording method for a magneto-optic information recording medium having at least one recording track defined by a land portion bounded by elongated groove portions along both sides of the land portion and having a track center, the method comprising, in any order, the steps of: projecting onto the track a first light beam having a first intensity, such that a mark corresponding to the first intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the first intensity being formed in at least one magnetic layer of a plurality of vertically anisotropic magnetic layers disposed thereon; and projecting a second light beam, with a center disposed at a positional offset with respect to the track center less than a known maximum, onto the track, the second light beam having a second intensity, such that a mark is formed which extends at least to the elongated groove portions along both sides of the land portion, the mark being formed in the at least one magnetic layer.

Claim 13

Dependent Claim 15 words

The method of claim 9, wherein the second intensity is less than the first intensity.

Claim 14

Dependent Claim 15 words

The method of claim 10, wherein the first and second light beams are laser beams.

Claim 15

Dependent Claim 18 words

The method of claim 9, wherein the plurality of vertically anisotropic magnetic layers includes is four magnetic layers.

Claim 16

Dependent Claim 62 words

The method of claim 9, wherein the magneto-optic information recording medium is formed of a lamination of ______________________________________ dielectric layer SiN.sub.x 65 nm magnetic layer Tb.sub.22 Fe.sub.69 Co.sub.9 80 nm magnetic layer Gd.sub.8 Dy.sub.17 Fe.sub.60 Co.sub.15 150 nm magnetic layer Tb.sub.30 Fe.sub.84 20 nm magnetic layer Tb.sub.30 Co.sub.70 40 nm protective layer SiN.sub.x 70 nm ______________________________________ on a substrate in that order.

Claim 17

Dependent Claim 252 words

An information recording method for a magneto-optic recording information medium comprising the steps of: providing on the magneto-optic recording information medium a track having a land portion, said land portion for carrying the two kinds of information, and said land portion having edges defining groove portions elongated on both sides of said land portion, the edges defining a track land width and the edges further defining a track center midway between the edges; overwriting two kinds of information corresponding to two kinds of light beams of different intensities by projecting onto the track the two kinds of light beams so as to have known beam widths and a maximum position error between a beam center and the track center such that the width of a portion of the kind of light beam having lower intensity which exceeds a predetermined intensity above which a mark is formed on the track is greater than the track land width by at least the maximum position error; and providing the magneto-optic recording information medium with a plurality of laminated magnetic layers with vertical magnetic anisotropy, one layer among which keeps its direction of magnetization constant and does not cause flux reversal at recording and reproducing and formed of a lamination of ______________________________________ dielectric layer SiN.sub.x 65 nm magnetic layer Tb.sub.22 Fe.sub.69 Co.sub.9 80 nm magnetic layer Gd.sub.8 Dy.sub.17 Fe.sub.60 Co.sub.15 150 nm magnetic layer Tb.sub.30 Fe.sub.84 20 nm magnetic layer Tb.sub.30 Co.sub.70 40 nm protective layer SiN.sub.x 70 nm ______________________________________ on a substrate in that order.

Claim 18

Dependent Claim 252 words

An information recording method for a magneto-optic recording information medium comprising the steps of: providing on the magneto-optic recording information medium a track having a land portion, said land portion for carrying the two kinds of information, and said land portion having edges defining groove portions elongated on both sides of said land portion, the edges defining a track land width and the edges further defining a track center midway between the edges; overwriting two kinds of information corresponding to two kinds of light beams of different intensities by projecting onto the track the two kinds of light beams so as to have known beam widths and a maximum position error between a beam center and the track center such that the width of a portion of the kind of light beam having lower intensity which exceeds a predetermined intensity above which a mark is formed on the track is greater than the track land width by at least the maximum position error; and providing the magneto-optic recording information medium with a plurality of laminated magnetic layers with vertical magnetic anisotropy, one layer among which keeps its direction of magnetization constant and does not cause flux reversal at recording and reproducing and formed of a lamination of ______________________________________ dielectric layer SiN.sub.x 65 nm magnetic layer Tb.sub.22 Fe.sub.69 Co.sub.9 80 nm magnetic layer Gd.sub.8 Dy.sub.17 Fe.sub.60 Co.sub.15 150 nm magnetic layer Tb.sub.30 Fe.sub.84 20 nm magnetic layer Tb.sub.30 Co.sub.70 40 nm protective layer SiN.sub.x 70 nm ______________________________________ on a substrate in that order.

Claim 19

Dependent Claim 261 words

An information recording method for a magneto-optic information recording medium having at least one recording track defined by a land portion bounded by elongated groove portions along both sides of the land portion and having a track center, the method comprising the steps of: projecting onto the track a first light beam having a first intensity, such that a mark corresponding to the first intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the first intensity being formed in at least one magnetic layer of a plurality of vertically anisotropic magnetic layers disposed thereon; and projecting a second light beam, with a center disposed at a positional offset with respect to the track center less than a known maximum, onto the track, the second light beam having a second intensity, and the second intensity being less than the first intensity, the second light intensity selected such that a mark corresponding to the second intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the second intensity being formed in the at least one magnetic layer and formed of a lamination of ______________________________________ dielectric layer SiN.sub.x 65 nm magnetic layer Tb.sub.22 Fe.sub.69 Co.sub.9 80 nm magnetic layer Gd.sub.8 Dy.sub.17 Fe.sub.60 Co.sub.15 150 nm magnetic layer Tb.sub.30 Fe.sub.84 20 nm magnetic layer Tb.sub.30 Co.sub.70 40 nm protective layer SiN.sub.x 70 nm ______________________________________ on a substrate in that order.

Claim 20

Dependent Claim 261 words

An information recording method for a magneto-optic information recording medium having at least one recording track defined by a land portion bounded by elongated groove portions along both sides of the land portion and having a track center, the method comprising the steps of: projecting onto the track a first light beam having a first intensity, such that a mark corresponding to the first intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the first intensity being formed in at least one magnetic layer of a plurality of vertically anisotropic magnetic layers disposed thereon; and projecting a second light beam, with a center disposed at a positional offset with respect to the track center less than a known maximum, onto the track, the second light beam having a second intensity, and the second intensity being less than the first intensity, the second light intensity selected such that a mark corresponding to the second intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the land portion, the mark corresponding to the second intensity being formed in the at least one magnetic layer and formed of a lamination of ______________________________________ dielectric layer SiN.sub.x 65 nm magnetic layer Tb.sub.22 Fe.sub.69 Co.sub.9 80 nm magnetic layer Gd.sub.8 Dy.sub.17 Fe.sub.60 Co.sub.15 150 nm magnetic layer Tb.sub.30 Fe.sub.84 20 nm magnetic layer Tb.sub.30 Co.sub.70 40 nm protective layer SiN.sub.x 70 nm ______________________________________ on a substrate in that order.

Claim 21

Dependent Claim 246 words

An information recording method for a magneto-optic information recording medium having at least one recording track defined by a land portion bounded by elongated groove portions along both sides of the land portion and having a track center, the method comprising, in any order, the steps of: projecting onto the track a first light beam having a first intensity, such that a mark corresponding to the first intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the least to the elongated groove portions along both sides of the land portion, the mark corresponding to the first intensity being formed in at least one magnetic layer of a plurality of vertically anisotropic magnetic layers disposed thereon; and projecting a second light beam, with a center disposed at a positional offset with respect to the track center less than a known maximum, onto the track, the second light beam having a second intensity, such that a mark is formed which extends at least to the elongated groove portions along both sides of the land portion, the mark being formed in the at least one magnetic layer and formed of a lamination of ______________________________________ dielectric layer SiN.sub.x 65 nm magnetic layer Tb.sub.22 Fe.sub.69 Co.sub.9 80 nm magnetic layer Gd.sub.8 Dy.sub.17 Fe.sub.60 Co.sub.15 150 nm magnetic layer Tb.sub.30 Fe.sub.84 20 nm magnetic layer Tb.sub.30 Co.sub.70 40 nm protective layer SiN.sub.x 70 nm ______________________________________ on a substrate in that order.

Claim 22

Dependent Claim 246 words

An information recording method for a magneto-optic information recording medium having at least one recording track defined by a land portion bounded by elongated groove portions along both sides of the land portion and having a track center, the method comprising, in any order, the steps of: projecting onto the track a first light beam having a first intensity, such that a mark corresponding to the first intensity is formed which extends across the land portion at least to the elongated groove portions along both sides of the least to the elongated groove portions along both sides of the land portion, the mark corresponding to the first intensity being formed in at least one magnetic layer of a plurality of vertically anisotropic magnetic layers disposed thereon; and projecting a second light beam, with a center disposed at a positional offset with respect to the track center less than a known maximum, onto the track, the second light beam having a second intensity, such that a mark is formed which extends at least to the elongated groove portions along both sides of the land portion, the mark being formed in the at least one magnetic layer and formed of a lamination of ______________________________________ dielectric layer SiN.sub.x 65 nm magnetic layer Tb.sub.22 Fe.sub.69 Co.sub.9 80 nm magnetic layer Gd.sub.8 Dy.sub.17 Fe.sub.60 Co.sub.15 150 nm magnetic layer Tb.sub.30 Fe.sub.84 20 nm magnetic layer Tb.sub.30 Co.sub.70 40 nm protective layer SiN.sub.x 70 nm ______________________________________ on a substrate in that order.

Claim 23

Dependent Claim 67 words

An information recording method as recited in one of claims 1 and 14, wherein the step of overwriting further comprises the step of: limiting the width of the portion of the kind of light beam having lower intensity which exceeds the predetermined intensity above which a mark is formed on the track to a width substantially equal to the track land width plus the maximum position error.

Claim 24

Dependent Claim 61 words

An information recording method as recited in one of claims 5, 9, 15 and 16, wherein the step of projecting the second light beam further comprises the step of: limiting the width of the second light beam such that a mark is formed on the track having a width substantially equal to the track land width plus the maximum position error.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1996-12-20	1997-06-21	1997-12-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2000-12-20	2001-06-21	2001-12-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2004-12-20	2005-06-21	2005-12-21	$7700.00	Window Closed / Lapsed

Information recording method and information recording apparatus for magneto-optic recording information medium

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