Re-writable optical disk having reference clock information permanently formed on the disk
USRE45292E1 · kind E1 · reissue
Assignee
Inventors
Key dates
| Filing date | Sep 19, 2012 |
| Grant date | Dec 16, 2014 |
| Priority date | — |
| Expiry date | Sep 19, 2032 |
Classification
- Technology area (CPC —)General
Abstract
An optical disk structure and optical disk recorder which enables data to be rewritten onto the recording layer of the optical disk. A clock reference structure is permanently formed along servo tracks of the optical disk. An optical transducer is coupled to the clock reference structure and generates a clock reference signal simultaneously with writing new data onto the recording layer of the optical disk. The data is written as data marks along the servo tracks. Each of the data marks includes edges. The edges of the data marks are recorded in synchronization with a write clock. The write clock is phase-locked with the clock reference signal. Therefore, the edges of the data marks are aligned with the clock reference structure with sub-bit accuracy. Standard DVD-ROM disk readers are not able to detect the high spatial frequency of the clock reference structure. Therefore, the optical disk structure and optical disk recorder of this invention allow production of re-writable optical disks which can be read by standard DVD-ROM disk readers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.