PURPOSE: To scatter force from concentrating to the periphery of a pit part by molding resin and consequently prevent the pit part from chipping and the like by a structure wherein the information pit part of a casting mold is made to be a circular or elliptical form.
CONSTITUTION: A casting mold of substrate for information recording medium is obtained by forming pre-format pattern with photoresist. In the pre-format pattern 2, each pit 3 is made to be a circular form. A cast molding device is formed by assembling a mirror-finished glass plate 6, the size of which is the same as said casting mold, and a spacer 7 to the casting mold. A substrate 9 for information recording medium is obtained by pouring prepolymer of acrylic resin blended with polymerization promotor in said device so as to be cured and unmolded. Since the pit 3 is circular, no chipping occurs at the peripheral part of the pre-format pattern 2 of the substrate 9 for information recording medium.
| JP2000233417 | ELASTIC BODY |
| WO/2003/013831 | METHOD AND APPARATUS FOR CONTACT LENS MOLD ASSEMBLY |
HIRAOKA MITSUO
TAMURA TOMOYUKI
SATO TETSUYA
