Information technology - Digitally recorded media for information interchange and storage - 120 mm Single Layer (25,0 Gbytes per disk) and Dual Layer (50,0 Gbytes per disk) BD Rewritable disk

This document specifies the mechanical, physical and optical characteristics of a 120 mm rewritable optical disk with a capacity of 25,0 Gbytes or 50,0 Gbytes. It specifies the quality of the recorded and unrecorded signals, the format of the data and the recording method, thereby allowing for information interchange by means of such disks. User data can be written, read and overwritten many times using a reversible method. This disk is identified as a BD rewritable disk.

This document specifies the following:

- two related but different types of this disk;

- conditions for conformance;

- environments in which the disk is to be operated and stored;

- mechanical and physical characteristics of the disk, which allow mechanical interchange between data processing systems;

- format of the information on the disk, including the physical disposition of the tracks and sectors;

- error-correcting codes and coding method used;

- characteristics of the signals recorded on the disk, which enable data processing systems to read data from the disk.

This document provides for interchange of disks between drives. Together with a standard for volume and file structure, it provides for ful