Optical disk and method of producing the same
US6957444B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 2003 |
| Grant date | Oct 18, 2005 |
| Priority date | — |
| Expiry date | Dec 29, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/258
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An optical disk includes a reflective layer, a recording layer, an optical-transparent bonding layer and an optical transparent sheet laminated on a substrate in this order. The total thickness of the optical-transparent bonding layer and the optical transparent sheet is 0.1 mm. The peak-to-peak height of wrinkles formed on the sheet is 2.5 μm or lower. The optical disk is produced as follows: A first ultraviolet ray is radiated to an optical transparent sheet at a first energy level in the range from 500 mJ/cm2 to 3000 mJ/cm2, a wavelength of the first ultraviolet ray being in the range from 250 nm to 300 nm. Prepared next is a substrate laminated on which are a reflective layer and a recording layer in this order. Ultraviolet hardened resin is applied on the recording layer to form an optical-transparent bonding layer thereon. An optical transparent sheet is provided on the optical-transparent bonding layer. A second ultraviolet ray is radiated to the optical transparent sheet at a second energy level the same as or lower than the first energy level, to harden the optical-transparent bonding layer, thus the optical transparent sheet being bonded on the substrate via the optical-t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.