SUBSTRATE SHEET FOR OPTICAL RECORDING MEDIUM AND METHOD AND APPARATUS FOR PRODUCING SUBSTRATE SHEET FOR OPTICAL RECORDING MEDIUM

摘要

PURPOSE:To improve productivity by separating a resin sheet forming stage and a preformat forming stage and using a resin roll having elasticity and heat insulating characteristic. CONSTITUTION:The pellets of polycarbonate are heated and melted by a ruder 1 and a molten resin sheet 14 is extruded by a T-die 2. This sheet is made into a resin sheet 15 having a uniform thickness by a resin roll 3. The sheet 15 and a molding roll 6 are then compression bonded by a compression bonding roll 10 via a photosetting resin compsn. layer 12. The layer 12 is cured by a photoirradiating means 9 and is integrated with the sheet 15, by which preformat patterns are transferred and formed and the substrate sheet 16 for optical recording media having the preformats 13 is obtd. Since the roll 3 having elasticity is used, the sheet is not forcibly rolled and the sheet substrate having smaller strains is obtd. The need for mirror finishing of the roll surface is eliminated and the roll working is facilitated by forming the layer 12 on the roll contact surface of the sheet 15. Since there is no need for frequent exchanges of the roll, the productivity is improved.