Process for producing optical disks

A process for producing optical disks comprising the steps of subjecting a photoresist layer on a substrate formed of silicon quartz, glass or a metal to light exposure, developing and etching treatments to obtain a stamper and then duplicating an information pattern for an optical disk from the stamper to a transparent plastic substrate by using a UV curable resin to prepare a replicated substrate of an optical disk, wherein the light exposure is conducted either by contacting a mask side surface of a photomask provided with a nontransparent mask having an information pattern for an optical disk to the photoresist side surface of said substrate having the photoresist layer or by noncontact projection, the photoresist layer of the non-irradiated regions is removed by developing, and the substrate surface provided thereunder is etched to give a raised pattern stamper having an information pattern for an optical disk, wherein plural stampers obtained by repeating the treatments of light exposure, developing and etching are fixed to a holder and plural replicated substrates are prepared by conducting a duplication process with said holder, wherein the duplication process comprises the steps of placing the UV curable resin in a convex form on a transparent plastic sheet moving continuously or intermittently, pressing the holder onto the resin, irradiating ultraviolet light to cure the UV curable resin, and then peeling the sheet off the stampers, and wherein, in the duplication process, at least three of said holders are used, the holders are pressed against the UV curable resin, and the ultraviolet light irradiation and the peeling of the resin from the stampers are conducted continuously.

A process for producing optical disks comprising the steps of subjecting a photoresist layer on a substrate formed of silicon quartz, glass or a metal to light exposure, developing and etching treatments to obtain a stamper and then duplicating an information pattern for an optical disk from the stamper to a transparent plastic substrate by using a UV curable resin to prepare a replicated substrate of an optical disk, wherein the light exposure is conducted either by contacting a mask side surface of a photomask provided with a nontransparent mask having an information pattern for an optical disk to the photoresist side of the substrate having the photoresist layer or by noncontact projection, the photoresist layer of the non-irradiated regions is removed by developing, and the substrate surface provided thereunder is etched to give a raised pattern stamper having an information pattern for an optical disk, wherein plural stampers obtained by repeating the treatments of light exposure, developing and etching are fixed to a holder and plural replicated substrates are prepared by conducting a duplication process with said holder, wherein the duplication process comprises the steps of placing the UV curable resin in a convex form on a transparent plastic sheet moving continuously or intermittently, pressing the holder onto the resin, irradiating ultraviolet light to cure the UV curable resin, and then peeling the sheet off the stampers, and wherein, in the duplication process, a holder having a polyhedron to each of the faces of which plural stampers have been fixed is used.