Comparison of high definition optical disc formats Blu-ray disc players since the end of the format war. Blu-ray Disc has a higher maximum disc capacity than HD DVD (50 GB vs. 30 GB for a double layered disc). In September 2007 the DVD Forum approved a preliminary specification for the triple-layer 51GB HD DVD (ROM only) disc though Toshiba never stated whether it was compatible with existing HD DVD players. In September 2006 TDK announced a prototype Blu-ray Disc with a capacity of 200GB. TDK was also the first to develop a Blu-ray prototype with a capacity of 100GB in May 2005. In October 2007 Hitachi developed
Picture disc many years later. These were deluxe picture discs, priced much higher than ordinary records, and they sold in very small numbers. In the early 1930s the entire record industry was being devastated by a worldwide economic depression and the proliferation of the new medium of radio, which made a wide variety of music available free of charge. Picture discs of all kinds were among the casualties. With the Great Depression and World War II no longer around to interfere with such modest luxuries, the picture disc reemerged in 1946, when Tom Saffardy's Sav-Way Industries began issuing Vogue Records. Vogues were