Patent US4972402A successfully refreshed from Google Patents.
US4972402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical card
Assignee: Canon Inc
•
Filing: 1987-11-16
•
Granted: 1990-11-20
•
Expires: 2007-11-16
Abstract
Abstract An optical card has a track portion and a track groove portion as the guide groove on a substrate which can be irradiated with coherent light in shape of a spot to detect the tracking signal from its reflected light, characterized in that the reflectance at the track groove portion is formed lower than the reflectance at the track portion.
Inventors
- 👤 Kyo Miura
- 👤 Hisaaki Kawade
- 👤 Yoshihiro Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:42
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B3/00; G11B3/68; G11B3/70; G11B3/705; G11B7/002; G11B7/0033; G11B7/24
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
60 words
An optical card having a track portion and a track groove portion as the guide groove on a substrate which can be irradiated with coherent light in shape of a spot to detect the tracking signal from its reflected light, characterized in that the reflectance at the track groove portion is formed lower than the reflectance at the track portion.
Claim 2
Dependent Claim
60 words
An optical card having a track portion and a track groove portion as the guide groove on a substrate which can be irradiated with coherent light in shape of a spot to detect the tracking signal from its reflected light, characterized in that the reflectance at the track groove portion is formed lower than the reflectance at the track portion.
Claim 3
Dependent Claim
23 words
An optical card according to claim 1, wherein said track groove portion has a material layer with lower reflectance than the recording layer.
Claim 4
Dependent Claim
53 words
An optical card according to claim 1, wherein the recording layer has a thickness of 1500 Å or more at the track groove portion, 800 to 1200 Å at the track portion, and said track groove portion has a depth of 2000 to 6000 Å and a width of 10,000 to 100,000 Å.
Claim 5
Dependent Claim
15 words
An optical card according to claim 3, wherein the recording layer is formed by coating.
Claim 6
Dependent Claim
24 words
An optical card according to claim 1, wherein the contrast ratio of said track portion to said track groove portion is 0.45 or more.
Claim 7
Dependent Claim
15 words
An optical card according to claim 1, wherein the recording layer contains an organic dye.
Claim 8
Dependent Claim
15 words
An optical card according to claim 6, wherein said organic dye is a polymethine dye.
Claim 9
Dependent Claim
16 words
An optical card according to claim 7, wherein said polymethine dye has the following formula: ##STR6##
Claim 10
Dependent Claim
15 words
An optical card according to claim 6, wherein said organic dye contains an additive therein.
Claim 11
Dependent Claim
26 words
An optical card according to claim 1, wherein said track portion comprises a pattern of a light-transmissive inorganic compound with higher thermal conductivity than the substrate.
References Cited (Backward Citations)
WO1983004335A1
Cited
US4606018A
Cited
US4584259A
Cited
US4587533A
Cited
US4748609A
Cited
EP0237873A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-19 | 1994-05-21 | 1994-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-19 | 1998-05-21 | 1998-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-19 | 2002-05-21 | 2002-11-20 | $7700.00 | Window Closed / Lapsed |