MEDIUM, DEVICE AND METHOD FOR RECORDING INFORMATION AND DEVICE, AND METHOD FOR REPRODUCING INFORMATION

摘要

PROBLEM TO BE SOLVED: To provide a recordable and regenerable information recording medium that is superior in precision in any of recording layers with several recording layers on one side. SOLUTION: The information recording medium is a disc-shaped one with several laminated recording layers (214 and 215). Each recording layer has a spiral track (14) composed of several circuits and at least one index header (12) aligned in the radial direction of a disc so as to block off one part of the spiral track. The index header has address data of each track recorded by an embossed pit. One part or all of the index header in each recording layer is arranged so as to overlap each other in terms of the plane of incidence of optical beam.