Title:
TWO-LAYER TYPE OPTICAL DISK AND OPTICAL DISK REPRODUCING DEVICE
Document Type and Number:
Japanese Patent JP3807233
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a two-layer type optical disk and an optical disk reproducing device suitable for reproducing the optical disk having two different thicknesses.
SOLUTION: The lead-in of one recording surface in the two-layer type optical disk is provided in the inner peripheral side and the lead-out of the same is provided in the outer peripheral side, while the lead-in of the other recording surface is provided in the outer peripheral side and the lead-out of the same is provided in the inner peripheral side. Thus, both of two layers are reproduced by an optical pickup moving on a closed locus. Also, the optimal substrate thickness of the optical disk viewed from an objective lens used in the optical pickup is specified by a<t<(a+b). Where a shows the thickness of the first substrate, b shows the thickness of the second substrate and t shows the optimal substrate thickness viewed from the objective lens. Thus, the device can cope with the two-layer type optical disk composed of the substrate having two different substrate thicknesses.
Inventors:
Ishibashi Toshiaki
Masayuki Inoue
Yoshio Suzuki
Masayuki Inoue
Yoshio Suzuki
Application Number:
JP2001034777A
Publication Date:
August 09, 2006
Filing Date:
March 17, 1995
Export Citation:
Assignee:
株式会社日立製作所
International Classes:
G11B7/004; G11B7/005; G11B7/007; G11B7/085; G11B7/24038; G11B7/2405; G11B7/24097; (IPC1-7): G11B7/007; G11B7/004; G11B7/005; G11B7/085; G11B7/24
Domestic Patent References:
| JP8147762A | ||||
| JP8171731A | ||||
| JP3054740A | ||||
| JP6223384A | ||||
| JP5234091A | ||||
| JP3219440A | ||||
| JP2046916U | ||||
| JP5151644A | ||||
| JP8212561A | ||||
| JP8255347A |
Attorney, Agent or Firm:
Manabu Inoue
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