Patent DE572893C successfully refreshed from Google Patents.
Patent US5258974A successfully refreshed from Google Patents.
US5258974A
Expired / Lapsed
US
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Optical read-out audio check disc with semitransparent defects or with single recorded tone
Assignee: Sony Corp
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Filing: 1990-05-23
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Granted: 1993-11-02
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Expires: 2010-05-23
Abstract
Abstract A check disc (1) has a single frequency signal recorded adjacent to the information signal tracks (TN), and simulated defects (2 to 4) are formed at predetermined track positions.
Inventors
- 👤 Noriyuki Ishimura
- 👤 Katsuji Yokoyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:33
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1816; G11B20/182; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
84 words
A check disc in which a plurality of semitransparent coating portions having a light transmissibility in a range of 30% to 60% are provided at respective predetermined positions on an information read-out surface of a substrate of the check disc, wherein said semitransparent coating portions have respectively different sizes and are respectively arranged in a shape of a circular arc and are formed so that their respective sizes gradually increase from the inner circumference of the disc to the outer circumference of the disc.
Claim 2
Dependent Claim
84 words
A check disc in which a plurality of semitransparent coating portions having a light transmissibility in a range of 30% to 60% are provided at respective predetermined positions on an information read-out surface of a substrate of the check disc, wherein said semitransparent coating portions have respectively different sizes and are respectively arranged in a shape of a circular arc and are formed so that their respective sizes gradually increase from the inner circumference of the disc to the outer circumference of the disc.
Claim 3
Dependent Claim
29 words
A check disc according to claim 1, wherein said semitransparent coating portions are provided by printing in a semitransparent ink on the information read-out surface of the disc substrate.
Claim 4
Dependent Claim
37 words
A check disc according to claim 1, wherein a predetermined single frequency signal is recorded on said disc next to each track containing an information signal at the positions at which said semitransparent coating portions are provided.
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) | 1996-11-01 | 1997-05-03 | 1997-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-01 | 2001-05-03 | 2001-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-01 | 2005-05-03 | 2005-11-02 | $7700.00 | Window Closed / Lapsed |