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1. (WO1998052192) METHOD FOR MACHINING MASTER OPTICAL DISK AND MASTERING DEVICE

Pub. No.:    WO/1998/052192    International Application No.:    PCT/JP1998/002174
Publication Date: Fri Nov 20 00:59:59 CET 1998 International Filing Date: Sat May 16 01:59:59 CEST 1998
IPC: G11B 7/00
G11B 7/135
G11B 7/26
Applicants: SEIKO EPSON CORPORATION

YAMADA, Hideaki

Inventors: YAMADA, Hideaki

Title: METHOD FOR MACHINING MASTER OPTICAL DISK AND MASTERING DEVICE
Abstract:
A method for machining a master optical disk which has a physical format and in which a rewritable optical disk constituted of a groove and pre-bit groups records a pre-bit group which is not on the same spiral as that of the groove by shifting the pre-bit group inward by, for example, a 1/2 track pitch from the center of the groove, which method comprises installing a light deflector utilizing an acoustooptic effect or another light deflector (101) utilizing an electrooptic effect on the optical path of a mastering device, thus deflecting one laser beam. This method makes laser beam machining possible at a plurality of arbitrary locations, for example, three locations at the center of the groove and two locations which are respectively shifted inward and outward by a 1/2 track pitch from the center of the groove with one scanning run for machining.