Naohiro Kimura

Practical study of saw-tooth wobble addressing by theoretical and experimental approaches

We have proposed a new concept of addressing in optical disks, the saw-tooth wobble (STW) groove. In this paper, the practical study of the STW by theoretical and experimental analyses is described. The address information corresponds to an even ordered-harmonic, so the write clock has no jitter factor. A 30 dB of carrier-to-noise ratio is sufficient for achieving 1E-2 of address error. Using a practical detection system, a radial tilt margin of more than ±0.6 degree is achieved.

Signal Qualification Method for Partial-Response Maximum-Likelihood Read/Write Channel

The partial-response maximum-likelihood (PRML) signal processing technique is effective for high-density recording media. However, there are few omit evaluation methods for qualifying the played-back signal using a simple measurement tool such as a jitter meter. We propose a simpler PRML qualification method, the so-called maximum-likelihood sequence error (MLSE) detection method. In this paper, we show the validity of the new method for dual-layer Blu-ray Disc read channel and, furthermore, show the method for optimizing the write channel.