Technical Journal

特集 録再ディスク

 MD (Mini Disc) is the most popular music recorder and portable music player in Japan. But other portable music players with HDDs (Hard Disk Drives) or silicon devices have become popular. In this situation, SONY announced the 1GB "Hi-MD" disc and portable recorder that incorporate DWDD (Domain Wall Displacement Detection) technology, leading to a maximum recording time of up to 45 hours for music data.
In this report, we propose the new integrated optical unit for MD pickups using polarized holograms, and PS-DPP (Phase-Shift Differential Push-Pull) method for RES (Radial Error Signal) detection. We develop a miniaturized integrated unit for MD pickups that can read two different types of discs, owing to two different retardation values of the phase compensation films, and to independence of the PS-DPP method on the track pitch of discs.

PDF版はこちらよりご覧頂けます。 (984kb)

前ページ 次ページ
ホーム > シャープについて > 技術情報 > Technical Journal > No.22 > 記事