US5056076A
Expired / Lapsed
US
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Method for controlling the rotational velocity of an information recording disk
Assignee: Sharp Corp
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Filing: 1990-04-10
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Granted: 1991-10-08
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Expires: 2010-04-10
Abstract
Abstract A method of controlling the rotational velocity of an information recording disk having one or more tracks in which patterns and marks are formed, the marks including at least one specific pattern having a predetermined length, which method comprises: measuring a time during which each of the patterns passes; detecting each of the marks on the basis of the values of the measured times; and controlling the rotational velocity of the disk on the basis of the measured time of the specific pattern of the detected mark, thereby making the linear velocity of the detected mark constant.
Inventors
- 👤 Kentaroh Tsuji
- 👤 Hiroshi Fuji
- 👤 Tomiyuki Numata
- 👤 Tsuneo Fujiwara
- 👤 Shigeo Terashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:20
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/20; G11B19/24; G11B19/247
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
138 words
A method of controlling the rotational velocity of an information recording disk having one or more tracks in which patterns and marks are formed, said marks including at least one specific pattern having a predetermined length, comprising the steps of: measuring at least one time interval during which each of said patterns and said marks passes; determining whether each of said patterns and said marks to which the measured time interval relates matches at least one said specific pattern of said marks, and if so, comparing said measured time interval with a predetermined time interval; and controlling the rotational velocity of the disk on the basis of said comparison, such that a succeeding time interval after said measured time interval is substantially equal to said predetermined time interval, for making the linear velocity of said detected mark constant.
Claim 2
Independent Claim
138 words
A method of controlling the rotational velocity of an information recording disk having one or more tracks in which patterns and marks are formed, said marks including at least one specific pattern having a predetermined length, comprising the steps of: measuring at least one time interval during which each of said patterns and said marks passes; determining whether each of said patterns and said marks to which the measured time interval relates matches at least one said specific pattern of said marks, and if so, comparing said measured time interval with a predetermined time interval; and controlling the rotational velocity of the disk on the basis of said comparison, such that a succeeding time interval after said measured time interval is substantially equal to said predetermined time interval, for making the linear velocity of said detected mark constant.
Claim 3
Dependent Claim
117 words
A method of controlling the rotational velocity of an information recording disk according to claim 1, wherein each said mark includes at least a first set of patterns including a first specific pattern and a second specific pattern, said first and second patterns having lengths which are different from one another, wherein said measuring step includes the steps of: measuring a first specific time interval during which the first specific pattern passes; measuring a second specific time interval during which the second specific pattern passes; and wherein said determining step includes the step of: generating a first ratio of the second time interval to the first time interval; and comparing the first ratio with a predetermined ratio.
Claim 4
Dependent Claim
129 words
A method of controlling the rotational velocity of an information recording disk according to claim 2, wherein each of said marks further includes a second set of said first and second specific patterns, said first and second sets being successively formed, wherein said measuring step further includes the steps of: measuring a third specific time interval during which the first specific pattern of said second set passes; measuring a fourth specific time interval during which the second specific pattern of said second set passes; and wherein said determining step further includes the steps of: generating a second ratio of the fourth time interval to the third time interval; and comparing the second ratio with said predetermined ratio, for determining when said predetermined ratio is successively generated at least twice.
Claim 5
Dependent Claim
57 words
A method of controlling the rotational velocity of an information recording disk according to claim 3, wherein the second specific pattern has a longer length than the first specific pattern, and wherein the step of controlling the rotational velocity of the disk includes the step of comparing said second specific time interval with said predetermined time interval.
Claim 6
Dependent Claim
44 words
A method of controlling the rotational velocity of an information recording disk according to claim 4, wherein the step of controlling the rotational velocity of the disk includes the step of taking a ratio of a predetermined value to the second specific time interval.
Claim 7
Dependent Claim
57 words
A method of controlling the rotational velocity of an information recording disk according to claim 2, wherein the second specific pattern has a longer length than the first specific pattern, and wherein the step of controlling the rotational velocity of the disk includes the step of comparing said second specific time interval with said predetermined time interval.
Claim 8
Dependent Claim
44 words
A method of controlling the rotational velocity of an information recording disk according to claim 6, wherein the step of controlling the rotational velocity of the disk includes the step of taking a ratio of a predetermined value to the second specific time interval.
Claim 9
Dependent Claim
81 words
An information recording disk having one or more tracks, wherein a plurality of marks are formed in said tracks, each said mark including at least a first set of patterns including a first specific pattern and a second specific pattern wherein each said pattern has a predetermined length, and wherein two patterns within a given mark are a fixed distance apart, the ratio of the length of said first specific pattern to the length of said second specific pattern being constant.
Claim 10
Dependent Claim
81 words
An information recording disk having one or more tracks, wherein a plurality of marks are formed in said tracks, each said mark including at least a first set of patterns including a first specific pattern and a second specific pattern wherein each said pattern has a predetermined length, and wherein two patterns within a given mark are a fixed distance apart, the ratio of the length of said first specific pattern to the length of said second specific pattern being constant.
Claim 11
Dependent Claim
19 words
An information recording disk according to claim 8, wherein said marks are formed at fixed intervals along said tracks.
Claim 12
Dependent Claim
19 words
An information recording disk according to claim 8, wherein said marks include two or more kinds of specific patterns.
Claim 13
Dependent Claim
23 words
An information recording disk according to claim 10, wherein said marks include two sets of said two or more kinds of specific patterns.
Claim 14
Dependent Claim
27 words
An information recording disk according to claim 11, wherein said two sets of said two or more kinds of specific patterns are successively formed along said tracks.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-10-07 | 1995-04-08 | 1995-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-07 | 1999-04-08 | 1999-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-07 | 2003-04-08 | 2003-10-08 | $7700.00 | Window Closed / Lapsed |