Patent US5128916A successfully refreshed from Google Patents.
US5128916A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical disc with alternating servo patterns and driving apparatus therefor
Assignee: Mitsubishi Electric Corp
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Filing: 1990-05-21
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Granted: 1992-07-07
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Expires: 2010-05-21
Abstract
Abstract An optical disc having a plurality of information tracks, each information track having a servo field including a pair of wobbled pits and a clock pit. The distance between one of the wobbled pits and the clock pit in each servo field is selected such that the optical disc includes at least three different types of servo field. These differnt types of servo field appear in a predetermined sequence for every one or more contiguous information tracks. A driving apparatus for driving such an optical disc has a direction detecting circuit for detecting the moving velocity of a movable portion of an optical head, and a speed detecting circuit for detecting the relative velocity of the movable portion.
Inventors
- 👤 Osamu Ito
- 👤 Masaharu Ogawa
- 👤 Kyosuke Yoshimoto
- 👤 Kunimaro Tanaka
- 👤 Teruo Furukawa
- 👤 Yoshiki Nakajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:32
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/007; G11B19/00; G11B19/20; G11B19/02; G11B19/04; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/30; G11B27/3027; G11B7/00745; G11B7/08; G11B7/085; G11B7/08505; G11B7/08529; G11B7/0857; G11B7/24; G11B7/2407; G11B7/24085
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
94 words
In an optical disc having a plurality of information tracks, each information track having a servo field including a pair of wobbled pits, a clock pit and at least one intermediate pit disposed between the wobbled pits, the improvement characterized in that the positions of the intermediate pits with respect to the wobbled pits are so selected that the optical disc includes at least three different types of servo field, and wherein the different types of servo field appear in a predetermined sequence, each type of servo field appearing for four contiguous information tracks.
Claim 2
Dependent Claim
94 words
In an optical disc having a plurality of information tracks, each information track having a servo field including a pair of wobbled pits, a clock pit and at least one intermediate pit disposed between the wobbled pits, the improvement characterized in that the positions of the intermediate pits with respect to the wobbled pits are so selected that the optical disc includes at least three different types of servo field, and wherein the different types of servo field appear in a predetermined sequence, each type of servo field appearing for four contiguous information tracks.
Claim 3
Dependent Claim
20 words
An optical disc as set forth in claim 1 wherein the number of different types of servo field is four.
Claim 4
Dependent Claim
94 words
In an optical disc having a plurality of information tracks, each information track having a servo field including a pair of wobbled pits, a clock pit and at least one intermediate pit disposed between the wobbled pits, the improvement characterized in that the positions of the intermediate pits with respect to the wobbled pits are so selected that the optical disc includes at least three different types of servo field, and wherein the different types of servo field appear in a predetermined sequence, each type of servo field appearing for two contiguous information tracks.
Claim 5
Dependent Claim
94 words
In an optical disc having a plurality of information tracks, each information track having a servo field including a pair of wobbled pits, a clock pit and at least one intermediate pit disposed between the wobbled pits, the improvement characterized in that the positions of the intermediate pits with respect to the wobbled pits are so selected that the optical disc includes at least three different types of servo field, and wherein the different types of servo field appear in a predetermined sequence, each type of servo field appearing for two contiguous information tracks.
Claim 6
Dependent Claim
20 words
An optical disc as set forth in claim 3 wherein the number of different types of servo field is eight.
Claim 7
Dependent Claim
107 words
An optical disc having a plurality of information tracks, each information track having a servo field; each servo field including a pair of wobbled pits, a clock pit and at least one intermediate pit being positioned between the wobbled pits; said information tracks having at least three different types of servo field, the positioning of the intermediate pit relative to the wobbled pits for one type of servo field being different from the positioning in a different type of servo field; and wherein the different types of servo field appear in a predetermined sequence, each type of servo field appearing for two or more contiguous information tracks.
Claim 8
Dependent Claim
107 words
An optical disc having a plurality of information tracks, each information track having a servo field; each servo field including a pair of wobbled pits, a clock pit and at least one intermediate pit being positioned between the wobbled pits; said information tracks having at least three different types of servo field, the positioning of the intermediate pit relative to the wobbled pits for one type of servo field being different from the positioning in a different type of servo field; and wherein the different types of servo field appear in a predetermined sequence, each type of servo field appearing for two or more contiguous information tracks.
Claim 9
Dependent Claim
243 words
An accessing apparatus for accessing an optical disc having a plurality of information tracks, each information track including a pair of wobbled pits, a clock pit and at least one intermediate pit disposed between the wobbled pits, the positions of the intermediate pits being so selected that the optical disc includes at least three different types of servo field, the different types of servo field appearing in a predetermine sequence, each type of servo field appearing for one or more contiguous information tracks, the apparatus comprising; a movable portion of an optical head adapted to be moved in the radial direction of said optical disc, said optical head for emitting a light onto the optical disc; photoelectric means for receiving a light reflected from the optical disc and converting the received light to an electrical signal; direction detecting means for detecting the positional relationship between the wobbled pits and the intermediate pits on the basis of the electrical signal from the photoelectric means, and for detecting the moving direction of the movable portion from a sequence of changes in the positional relationship; speed detecting means for detecting the magnitude of relative velocity of the movable portion in the radial direction with respect to the optical disc on the basis of the electrical signal of the photoelectrical means; and velocity controlling means responsive to output signals from the direction detecting means and the speed detecting means for controlling the velocity of the movable portion.
Claim 10
Dependent Claim
243 words
An accessing apparatus for accessing an optical disc having a plurality of information tracks, each information track including a pair of wobbled pits, a clock pit and at least one intermediate pit disposed between the wobbled pits, the positions of the intermediate pits being so selected that the optical disc includes at least three different types of servo field, the different types of servo field appearing in a predetermine sequence, each type of servo field appearing for one or more contiguous information tracks, the apparatus comprising; a movable portion of an optical head adapted to be moved in the radial direction of said optical disc, said optical head for emitting a light onto the optical disc; photoelectric means for receiving a light reflected from the optical disc and converting the received light to an electrical signal; direction detecting means for detecting the positional relationship between the wobbled pits and the intermediate pits on the basis of the electrical signal from the photoelectric means, and for detecting the moving direction of the movable portion from a sequence of changes in the positional relationship; speed detecting means for detecting the magnitude of relative velocity of the movable portion in the radial direction with respect to the optical disc on the basis of the electrical signal of the photoelectrical means; and velocity controlling means responsive to output signals from the direction detecting means and the speed detecting means for controlling the velocity of the movable portion.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-07 | 1996-01-06 | 1996-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-07 | 2000-01-06 | 2000-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-07 | 2004-01-06 | 2004-07-07 | $7700.00 | Window Closed / Lapsed |