OPTICAL RECORDING MEDIUM, STAMPER, AND OPTICAL RECORDING MEDIUM MANUFACTURING METHOD

摘要

Conventionally, at an outer peripheral portion of an optical recording medium it often becomes difficult to assure a stable servo signal during recording or to assure a high−quality signal during reproduction. An optical recording medium including a substrate (101) having a groove (106) and a recording layer (102) formed on the substrate (101), wherein the width of the groove (106) becomes substantially greater at the outer side of the substrate (101).