US4916683A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical recording/reproducing apparatus with means to shift light beam periodically to prevent record medium deterioration
Assignee: Hitachi Ltd
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Filing: 1989-02-01
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Granted: 1990-04-10
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Expires: 2009-02-01
Abstract
Abstract When it is detected that the light spot stays in a same track for a time exceeding a predetermined length of time, the light spot is moved to any other track. Thus, the light spot is prevented from staying on a same track for a long time without recording/reproducing data.
Inventors
- 👤 Takuya Mizokami
- 👤 Shinichi Arai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:26
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/02; G11B19/04; G11B7/00; G11B7/007; G11B7/00745
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
93 words
A method for optically recording and reproducing data by projecting a light spot onto one of plural tracks on an optical disk, comprising the following steps of: detecting that the light spot stays on a same track without doing any data recording/reproduction; measuring a time for which the light spot stays on said same track, said step of measuring a time comprising the step of measuring the number of rotations of the optical disk; and moving the light spot to any other track when said measured time exceeds a predetermined length of time.
Claim 2
Independent Claim
93 words
A method for optically recording and reproducing data by projecting a light spot onto one of plural tracks on an optical disk, comprising the following steps of: detecting that the light spot stays on a same track without doing any data recording/reproduction; measuring a time for which the light spot stays on said same track, said step of measuring a time comprising the step of measuring the number of rotations of the optical disk; and moving the light spot to any other track when said measured time exceeds a predetermined length of time.
Claim 3
Dependent Claim
14 words
A method according to claim 1, in which said optical disk has spiral tracks.
Claim 4
Dependent Claim
14 words
A method according to claim 1, in which said optical disk has concentrical tracks.
Claim 5
Dependent Claim
34 words
A method according to claim 1, in which the number of rotations of the optical disk is measured by counting a signal generated each time the light spot passes by sectors on the track.
Claim 6
Dependent Claim
15 words
A method according to claim 4, in which said signal is a sector mark signal.
Claim 7
Dependent Claim
26 words
A method according to claim 1, in which said other track to which the light spot is moved is a track adjacent to said same track.
Claim 8
Dependent Claim
28 words
A method according to claim 1, in which said other track to which the light spot is moved exists in a guard band located outside the user area.
Claim 9
Independent Claim
166 words
A method for optically recording and reproducing data by projecting a light spot onto an optical disk having spiral tracks each divided into plural sectors, each track having a jump sector, comprising the following steps of: detecting that a time for which no data recording/reproduction is done exceeds a predetermined length of time; generating a signal indicating that the light spot has passed by the sectors on a track; detecting the sector number of a sector in which the light spot stays at a time and also detecting, based on the detected sector number and said signal, the sector number of a sector in which the light spot is currently staying; generating a sector jump command signal when the sector number detected an the preceding step coincides with that of the jump sector; and inhibiting, when the time for which no data recording/reproduction is done at the first step is judged to exceed the predetermined length of time, said sector jump command signal from being generated.
Claim 10
Independent Claim
166 words
A method for optically recording and reproducing data by projecting a light spot onto an optical disk having spiral tracks each divided into plural sectors, each track having a jump sector, comprising the following steps of: detecting that a time for which no data recording/reproduction is done exceeds a predetermined length of time; generating a signal indicating that the light spot has passed by the sectors on a track; detecting the sector number of a sector in which the light spot stays at a time and also detecting, based on the detected sector number and said signal, the sector number of a sector in which the light spot is currently staying; generating a sector jump command signal when the sector number detected an the preceding step coincides with that of the jump sector; and inhibiting, when the time for which no data recording/reproduction is done at the first step is judged to exceed the predetermined length of time, said sector jump command signal from being generated.
Claim 11
Dependent Claim
37 words
A method according to claim 8, in which it is detected, by measuring the number of rotations of the optical disk, that said time for which no data recording/reproduction is done exceeds the predetermined length of time.
Claim 12
Dependent Claim
35 words
A method according to claim 9, in which the number of rotations of the optical disk is measured by counting a signal generated each time the light spot passes by plural sectors on a track.
Claim 13
Dependent Claim
15 words
A method according to claim 9, in which said signal is a sector mark signal.
Claim 14
Independent Claim
94 words
An apparatus for optically recording and reproducing data by projecting a light spot onto one of plural tracks on an optical track, comprising: first means for detecting that the light spot stays on a same track without doing any data recording/reproduction; second means for measuring a time for which the light spot stays on said same track, said second means comprising means for measuring the number of rotations of the optical disk; and third means for moving the light spot to any other track when said measured time exceeds a predetermined length of time.
Claim 15
Independent Claim
94 words
An apparatus for optically recording and reproducing data by projecting a light spot onto one of plural tracks on an optical track, comprising: first means for detecting that the light spot stays on a same track without doing any data recording/reproduction; second means for measuring a time for which the light spot stays on said same track, said second means comprising means for measuring the number of rotations of the optical disk; and third means for moving the light spot to any other track when said measured time exceeds a predetermined length of time.
Claim 16
Dependent Claim
14 words
An apparatus according to claim 12, in which said optical disk has spiral tracks.
Claim 17
Dependent Claim
14 words
An apparatus according to claim 12, in which said optical disk has concentrical tracks.
Claim 18
Dependent Claim
36 words
An apparatus according to claim 12, in which the number of rotations of the optical disk is measured by counting a signal generated each time the light spot passes by the sectors present on a track.
Claim 19
Dependent Claim
15 words
An apparatus according to claim 15, in which said signal is a sector mark signal.
Claim 20
Dependent Claim
26 words
An apparatus according to claim 12, in which said other track to which the light spot is moved is a track adjacent to said same track.
Claim 21
Dependent Claim
28 words
An apparatus according to claim 12, in which said other track to which the light spot is moved exists in a guard band located outside the user area.
Claim 22
Independent Claim
175 words
An apparatus for optically recording and reproducing data by projecting a light spot onto an optical disk having spiral tracks each divided into plural sectors, each track having a jump sector, comprising: first means for detecting that a time for which no data recording/reproduction is done exceeds a predetermined length of time; second means for generating a signal indicating that the light spot has passed by sectors present on a track; third means for detecting the sector number of a sector in which the light spot stays at a time and also detecting, based on the detected sector number and said signal, the sector number of a sector in which the light spot is currently staying; fourth means for generating a sector jump command signal when the sector number detected by said third means coincides with the sector number of the jump sector; and fifth means for inhibiting, when the time for which no data recording/reproduction is done is judged to exceed the predetermined length of time, said sector jump command signal from being generated.
Claim 23
Independent Claim
175 words
An apparatus for optically recording and reproducing data by projecting a light spot onto an optical disk having spiral tracks each divided into plural sectors, each track having a jump sector, comprising: first means for detecting that a time for which no data recording/reproduction is done exceeds a predetermined length of time; second means for generating a signal indicating that the light spot has passed by sectors present on a track; third means for detecting the sector number of a sector in which the light spot stays at a time and also detecting, based on the detected sector number and said signal, the sector number of a sector in which the light spot is currently staying; fourth means for generating a sector jump command signal when the sector number detected by said third means coincides with the sector number of the jump sector; and fifth means for inhibiting, when the time for which no data recording/reproduction is done is judged to exceed the predetermined length of time, said sector jump command signal from being generated.
Claim 24
Dependent Claim
22 words
An apparatus according to claim 19, wherein said first means comprises means for measuring the number of rotations of the optical disk.
Claim 25
Dependent Claim
35 words
An apparatus according to claim 20, in which said number of rotations of the optical disk is measured by counting a signal generated each time the light spot passes by plural sectors on a track.
Claim 26
Dependent Claim
15 words
An apparatus according to claim 21, in which said signal is a sector mark signal.
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) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |