EP0192244A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
An optical disc
Assignee: Maxell Ltd
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Filing: 1986-02-18
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Granted: —
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Expires: 2006-02-18
Abstract
Abstract In an optical disc according to the present invention, first (5) and second (8) discs comprise a hub half (14) inserted into the center portion of a disc substrate respectively, the hub half (14) is arranged at the center of the disc substrate, and a recording layer (9) is formed on the disc substrate by using the center portion of the hub half as a reference point. Therefore, the center of the recording layer can not be shifted from the center of the hub half and the optical disc with high reliability can be provided when recording and playing back an information.
Inventors
- 👤 Tosio Higasihara
- 👤 Ken Yoshizawa
- 👤 Masahiro Suzuki
- 👤 Akira Gotoh
- 👤 Yoshitane Tuburaya
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 04:29
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/24015; G11B7/24097; G11B7/26
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
156 words
An optical disc comprising a first disc comprising a first hub half having a cylindrical portion and a first disc substrate with a center hole, wherein the first hub half and the first disc substrate are constructed as one body by inserting the cylindrical portion of the first hub half into the center hole of the first disc substrate, and a second disc comprising a second hub half having a cylindrical portion and a second disc substrate with a center hole, wherein the second hub half and the second disc substrate are constructed as one body by inserting the cylindrical portion of the second hub half into the center hole of the second disc substrate, wherein a surface of the first hub half and a surface of the second hub half are connected, so that the first hub half and second hub half are connected as one body and the first disc faces the second disc.
Claim 2
Dependent Claim
156 words
An optical disc comprising a first disc comprising a first hub half having a cylindrical portion and a first disc substrate with a center hole, wherein the first hub half and the first disc substrate are constructed as one body by inserting the cylindrical portion of the first hub half into the center hole of the first disc substrate, and a second disc comprising a second hub half having a cylindrical portion and a second disc substrate with a center hole, wherein the second hub half and the second disc substrate are constructed as one body by inserting the cylindrical portion of the second hub half into the center hole of the second disc substrate, wherein a surface of the first hub half and a surface of the second hub half are connected, so that the first hub half and second hub half are connected as one body and the first disc faces the second disc.
Claim 3
Dependent Claim
76 words
The optical disc as fined in claim 1, wherein the first hub half of the first disc further comprises a flange portion arranged at the end of the cylindrical portion of the first hub half, the second hub half of the second disc further comprises a flange portion arranged at the end of the cylindrical portion of the second hub half, and the first hub half is connected to the second hub half as one body.
Claim 4
Dependent Claim
41 words
The optical disc as -defined in claim 2, wherein the first and second hub halves comprise a cylindrical body and a flange body in an annular shape respectively, and the flange body is connected on the cylindrical body as one body.
Claim 5
Dependent Claim
22 words
The optical disc as defined in claim 3, wherein the flange body is connected on the cylindrical body with a bonding material.
Claim 6
Dependent Claim
27 words
The optical disc as defined in claim 2, wherein a recording layer is formed on at least one side surface of the first and second disc substrates.
Claim 7
Dependent Claim
51 words
The optical disc as defined in claims 2 or 5, wherein the flange potions of the first and second hub halves are constructed as one body between the first and second substrates so that the flange portion of the first hub half faces the flange portion of the second hub half.
Claim 8
Dependent Claim
57 words
The optical disc as defined in any of claims 2 through 6, wherein the flange portion of the first hub half is connected to the flange portion of the second hub half with a bonding material on the condition that the flange portion of the first hub half faces the flange portion of the second hub half.
Claim 9
Dependent Claim
34 words
The optical disc as defined in claim 6, wherein a bonding recess is formed on at least one end surface of the flange portions of the first and second hub halves, facing each other.
Claim 10
Dependent Claim
121 words
The optical disc as defined in claim 1, wherein the first disc substrate is connected to the first hub half with a bonding material, the second disc substrate is connected to the second hub half with a bonding material, an inner spacer is arranged between the first and second discs engaging in the outer surfaces of the cylindrical portions of the first and second hub half on the condition that the first disc substrate faces the second disc substrate, the inner spacer is connected to the first and second disc substrates with a bonding material, the inner-spacer is connected to the outer surfaces of the first and second hub halves, thereby the first and second discs are connected as one body.
Claim 11
Dependent Claim
101 words
The optical disc as defined in claim 2, wherein the first disc substrate is connected to the first hub half with a bonding material, the second disc substrate is connected to the second hub half with a bonding material, an inner spacer is arranged at the outside of the flange portions of the first and second hub halves, the inner spacer is connected to the first and second disc substrates as one body with a bonding material, and the inner spacer is connected to the flange portions of the first and second hub halves as one body with a bonding material.
Claim 12
Dependent Claim
101 words
The optical disc as defined in claim 2, wherein the first disc substrate is connected to the first hub half with a bonding material, the second disc substrate is connected to the second hub half with a bonding material, an inner spacer is arranged at the outside of the cylindrical portions of the first and second hub halves, the inner spacer is connected to the first and second disc substrates as one body with a bonding material, and the inner spacer is connected to the cylindrical portions of the first and second hub halves as one body with a bonding material.
Claim 13
Dependent Claim
55 words
The optical disc as defined in claims 1, 2, or 9 through 11, wherein the first and second disc substrates are- made of glass, and the first and second hub halves are made of an alloy of iron, nickel and chromium, containing nickel at 42 percent by weight and chromium at 6 percent by weight.
Claim 14
Dependent Claim
49 words
A process of making an optical disc comprising steps of arranging a hub half at the center of a disc substrate, and forming a recording layer having at least a tracking information on the disc substrate by using the center portion of the hub half as a reference point.
Claim 15
Dependent Claim
49 words
A process of making an optical disc comprising steps of arranging a hub half at the center of a disc substrate, and forming a recording layer having at least a tracking information on the disc substrate by using the center portion of the hub half as a reference point.
Claim 16
Dependent Claim
57 words
The process as defined in claim 13 further comprising steps of arranging a spindle projected from a surface of a stamper on the stamper having at least one groove arranged on the surface of the stamper, and positioning the disc substrate relative to the stamper by inserting the spindle into a center hole of the hub half.
Claim 17
Dependent Claim
163 words
A process of making an optical disc comprising steps of arranging a first hub half at the center of a first disc substrate, v arranging a second hub half at the center of a second disc substrate, forming a first recording layer having at least a tracking information on the first disc substrate by using the center portion of the first hub half as a reference point, forming a second recording layer having at least a tracking information on the second disc substrate by using the center portion of the second hub half as a reference point, positioning the first and second substrates by using a center hole of the first hub half and center hole of the second hub half after making the first substrate face the second substrate so that the first recording layer faces the second recording layer, and constructing the first substrate with the first hub half and the second substrate with the second hub half as one body.
Claim 18
Dependent Claim
163 words
A process of making an optical disc comprising steps of arranging a first hub half at the center of a first disc substrate, v arranging a second hub half at the center of a second disc substrate, forming a first recording layer having at least a tracking information on the first disc substrate by using the center portion of the first hub half as a reference point, forming a second recording layer having at least a tracking information on the second disc substrate by using the center portion of the second hub half as a reference point, positioning the first and second substrates by using a center hole of the first hub half and center hole of the second hub half after making the first substrate face the second substrate so that the first recording layer faces the second recording layer, and constructing the first substrate with the first hub half and the second substrate with the second hub half as one body.
References Cited (Backward Citations)
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