Patent EP0289309A2 successfully refreshed from Google Patents.
EP0289309A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
An apparatus for reading an optical disk
Assignee: Sharp Corp
•
Filing: 1988-04-28
•
Granted: —
•
Expires: 2008-04-28
Abstract
Abstract An apparatus for reading an optical disk having tangentially extending tracks (Q1, Q2), including: a driving device for moving at least one light spot (A, B1, B2); a first circuit means for producing a tracking error signal (S1) which indicates a deviation of the light spot (A) from one of the tracks (Q1, Q2); and a second circuit means (7) for producing acceleration and deceleration signals (S6), the driving device being controlled to affect a track jump of the light spot (A) in accordance with the acceleration and deceleration signals (S6). The second circuit means (7) produces the acceleration signal when a track jump is to be initiated, and produces the deceleration signal when the ratio of the level of the tracking error signal (S1) to the peak value (S3) of the tracking error signal becomes a predetermined value.
Inventors
- 👤 Kunio Kojima
- 👤 Noriaki Sakamoto
- 👤 Toshihisa Deguchi
- 👤 Daiji Yamane
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 11:43
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/085; G11B7/08505; G11B7/08529; Y; Y02; Y02P; Y02P80/00; Y02P80/10; Y02P80/15
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
147 words
An apparatus for reading an optical disk having tangentially extending tracks (Q₁, Q₂) including: a driving device for moving at least one light spot (A, B₁, B₂) a first circuit means for producing a tracking error signal (S₁) which indicates a deviation of said light spot (A) from one of said tracks (Q₁, Q₂) and a second circuit means (7) for producing acceleration and deceleration signals (S₆), said driving device being controlled to affect a track jump of said light spot (A) in accordance with said acceleration and deceleration signal (S₆), the improvement exists in that said second circuit means (7) produces the acceleration signal (S₆) when a track jump is to be initiated, and produces the deceleration signal (S₆) when the ratio of the level of said tracking error signal (S₁) to the peak value (S₃) of said tracking error signal (S₁) becomes a predetermined value.
Claim 2
Independent Claim
147 words
An apparatus for reading an optical disk having tangentially extending tracks (Q₁, Q₂) including: a driving device for moving at least one light spot (A, B₁, B₂) a first circuit means for producing a tracking error signal (S₁) which indicates a deviation of said light spot (A) from one of said tracks (Q₁, Q₂) and a second circuit means (7) for producing acceleration and deceleration signals (S₆), said driving device being controlled to affect a track jump of said light spot (A) in accordance with said acceleration and deceleration signal (S₆), the improvement exists in that said second circuit means (7) produces the acceleration signal (S₆) when a track jump is to be initiated, and produces the deceleration signal (S₆) when the ratio of the level of said tracking error signal (S₁) to the peak value (S₃) of said tracking error signal (S₁) becomes a predetermined value.
Claim 3
Independent Claim
202 words
An apparatus for reading an optical disk having tangentially extending tracks (Q₁, Q₂), including: a driving device for moving at least one light spot (A, B₁, B₂) a first circuit means for producing a tracking error signal (S₁) which indicates a deviation of said light spot (A) from one of said tracks (Q₁, Q₂); and a second circuit means (7) for producing acceleration and deceleration signals (S₆), said driving device being controlled to affect a track jump of said light spot (A) in accordance with said acceleration and deceleration signals (S₆), the improvement exists in comprising: a holding means (3, D₁, D₂, C₁) for holding a peak value (S₃) of said tracking error signal (S₁); a third circuit means (4, 6, Vr₁) for obtaining a ratio of the level of said tracking error signal (S₁) to said peak value (S₃) held by said holding means (3, D₁, D₂, C₁); and a comparing means (6) for producing a timing signal (S₅) the state of which changes when said ratio reaches a predetermined value, said second circuit means (7) producing the acceleration signal (S₆) when a track jump is to be initiated, and producing the deceleration signal (S₆) when receiving said timing signal (S₅).
Claim 4
Independent Claim
202 words
An apparatus for reading an optical disk having tangentially extending tracks (Q₁, Q₂), including: a driving device for moving at least one light spot (A, B₁, B₂) a first circuit means for producing a tracking error signal (S₁) which indicates a deviation of said light spot (A) from one of said tracks (Q₁, Q₂); and a second circuit means (7) for producing acceleration and deceleration signals (S₆), said driving device being controlled to affect a track jump of said light spot (A) in accordance with said acceleration and deceleration signals (S₆), the improvement exists in comprising: a holding means (3, D₁, D₂, C₁) for holding a peak value (S₃) of said tracking error signal (S₁); a third circuit means (4, 6, Vr₁) for obtaining a ratio of the level of said tracking error signal (S₁) to said peak value (S₃) held by said holding means (3, D₁, D₂, C₁); and a comparing means (6) for producing a timing signal (S₅) the state of which changes when said ratio reaches a predetermined value, said second circuit means (7) producing the acceleration signal (S₆) when a track jump is to be initiated, and producing the deceleration signal (S₆) when receiving said timing signal (S₅).
Claim 5
Dependent Claim
51 words
An apparatus for reading an optical disk according to claim 2, wherein said holding means (3, D₁, D₂, C₁) holds a peak value (S₃) of said tracking error signal (S₁) while said light spot (A) moves from one track or track portion (Q₁) to an adjacent track or track portion (Q₂).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.