High-Speed Recording up to 15,000 rpm Using Thin Optical Disks

We propose a high-speed optical disk system using thin flexible optical disks (HS-FOD) recording up to 15,000 rpm. The thin optical disk system is composed of three technical elements: media employing a thin and flexible substrate 0.1 mm thick, a mechanical stabilizer, and a high-speed tracking servo employing a feed-forward control with zero phase error tracking (ZPET-FF control). The HS-FOD system has an optical head with numerical aperture (NA) of 0.85 and is compatible with the optical system of a Blu-ray disc or a broadcast-use optical disk. We have successfully performed disk rotation stably and have performed precisely a focus servo and a tracking servo at 15,000 rpm. We also achieved writing and reading data at 15,000 rpm and recording 252 Mbps of random pattern data and could get small values of jitter below the tolerance. These results are enough to record professional high-definition television (HDTV) video signals in formats such as HD-D5 for broadcast-use.