OPTIACL INFORMATION RECORDING AND REPRODUCING DEVICE AND DISCOID RECORDING MEDIUM

摘要

PURPOSE:To prevent timing error of information due to uneven rotation from being caused by providing a positioning means to a recording medium and a rotating mechanism. CONSTITUTION:A disc 7 being a recording medium and a turntable 12 of the rotating mechanism are provided respectively with a notch 7b for positioning and a projection 12a for positioning and the disc 7 and the table 12 have always a constant relative positioning relation. Thus, the generation of timing error onto optical information due to uneven rotation is prevented.