2.3 Optical carriers

Optical carriers are the oldest audiovisual carriers. They have been in use for analogue image representation for more than 170 years. For the storage of audio and video signals, however, they are amongst the youngest group of carriers. Although optical tape formats have been developed, they have not reached market acceptance. Therefore, optical audio and video carriers are restricted to disc13 formats.

13. Spelling of disc vs. disk; this publication joins the orthography of IASA-TC 04, second edition: all analogue and optical discs are spelled discs; magnetic disks are spelled disk.