Multi-layer writable optical record carrier with an optimum power calibration area, and method and apparatus for forming optimum power calibration areas on such a record carrier

摘要

A writable optical record carrier comprising a plurality of recording layers L0, . . . , Ln−1 separated by a spacer material, each recording layer comprising an optimum power calibration area having a first portion with an average reflection value representative of a recorded layer and a second portion with an average reflection value representative of an unrecorded layer, a method, and an apparatus for forming optimum power calibration areas on such a writable optical record carrier are presented. The optimum power calibration areas partially overlap such that the optimum power calibration areas of each pair of consecutive recording layers form a step, and the first portions of said plurality of recording layers have the form of a staircase. Each step formed by a pair of consecutive recording layers k, k+1 has a preferred minimum step size.