HD DVD had declined to say whether the 51 GB disc was compatible with existing drives and players. Specification 2.0 Part 1 (Physical Specification) for triple layer HD DVD had been approved in November 2007. At the CES 2007, Ritek revealed their high definition optical disc process that extended both competing high definition formats to ten layers, increasing capacity to 150 GB for HD DVD and 250 GB for Blu-ray Disc. A major obstacle to implementing this technology in either format (150 GB HD DVD will not be developed due to HD DVD's discontinuation) is that reader-writer technology available may not be
Archival Disc Archival Disc Archival Disc (AD) is the name of a trademark owned by Sony Corporation and Panasonic Corporation describing an optical disc storage medium designed for long-term digital storage. First announced on 10 March 2014 and planned to be introduced in the second quarter of 2015, the discs are intended to be able to withstand changes in temperature and humidity, in addition to dust and water, ensuring that the disc is readable for at least 50 years. The agreement between Sony and Panasonic to jointly develop the upcoming generation optical media standard was first announced on 29 July 2013. The