METHOD AND APPARATUS FOR PRODUCING MASTER DISK FOR OPTICAL DISK AND SAID OPTICAL DISK

摘要

PURPOSE:To produce a master disk for an optical disk having high dimensional accuracy by rotating and radially moving a substrate continuously at an equal speed and moving the optical axis of a light beam to form and expose track patterns thereon. CONSTITUTION:The light from an Ar laser light emitting source 11 is modulated by an A0 modulator 12 and the light beam is projected on the substrate 15 via a galvanomirror 13 and a recording head 14 while the substrate 15 on which a sensitizing agent is coated is kept rotated at an equal speed. The head 14 and the substrate 15 are relatively moved in the radial direction of the substrate 15 to form the track patterns on the substrate 15. Exposing is executed in this case so as to draw the locus of the 1st round of the prescribed tracks or bit arrays while the optical axis of the light beam is moved in the direction for decreasing or increasing the relative moving speed of the head 14 and the substrate 15. The irradiation of the light beam is stopped and the optical axis is returned to the home position on the next one turn of the substrate while the equal speed of the substrate 15 is maintained. This operation is further repeated for the next and ensuing tracks or bit arrays as well.