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Key technology for high density rewritable DVD (DVD-RAM)

1998; IEEE Magnetics Society; Volume: 34; Issue: 2 Linguagem: Inglês

10.1109/20.667758

1941-0069

Ikuo Satoh, Shunji Ohara, Nobuo Akahira, Mutsuo Takenaga,

Iterative Learning Control Systems

DVD-RAM requires a large storage capacity to write and read huge amounts of data such as MPEG2 and AV as well as computer data for full-scale multi-media applications. Its format is focused on unifying AV and computer files, and achieving read compatibility with DVD-ROM drive. DVD-RAM has been realized by using phase change media, 0.6 mm substrate, 650 nm laser and NA 0.6 lens. The track has a single-spiral wobbled land and groove format. Each sector in land and groove tracks can be accessed in a seamless manner by combining physical headers and the wobble signal. 8-16 modulated signal is overwritten on land and groove tracks with mark edge recording method. The sector position shifting of 8 bytes and two guard fields located at the top and end of the data field are introduced to prevent the signal deterioration caused by repeating overwrites. DVD-RAM disc has wide tolerances of laser power and disc tilt, and overwrite durability of over 10/sup 5/ cycles. It is also concluded that DVD-RAM is high reliable and compatible for reading by DVD-ROM drives.