I've just seen a BBC story stating that, as predicted, Toshiba has given up in the battle over high definition DVDs. It means that Sony's Blu-Ray technology will become the industry standard over Toshiba's HD format.
Sony of course lost the battle over video formats back in the late 1970s and the 1980s. VHSÂ® defeated Betamax which was technically superior but could not record longer programmes such as films, and was generally outmanouevred in the publicity war.
Although there has been (mainly Korean) work on machines that can take either format, most machines that can take high definition DVDs can only cope with one format. High definition has become very popular as its means far more clarity than you get on a normal television screen. If you want to see what it's like, try playing a DVD film on a PC and see the clarity.
High definition is very demanding in memory, and standard DVDs would only be able to show about 10 minutes of such films.
In February 2002 Sony, Matsushita and Philips announced their new DVD concept, Blu-ray. I believe that the relevant invention is this patent, which was applied for by all three companies. Here is its main drawing.
Oddly, it carries a â€śpriority dateâ€ť of the initial filing for May 2002, which is later. Four Japanese and two Dutchmen are listed as the inventors. It uses a 0.1mm disk substrate layer that allows up to 23Gbytes of storage on one side of a DVD. That requires new tooling and equipment, raising production costs. It is backwards compatible with DVD or CD. It uses violet-blue lasers, which have a shorter wavelength (450 nm) than normal lasers, so that substantially more data can be stored on a Blu-ray Disc than on the DVD format, which uses a red 650 nm laser.
Because Blu-ray places the data recording layer close to the surface of the disc, early discs were susceptible to contamination and scratches, and had to be encased in plastic caddies for protection. This would have been likely to hurt sales, and the discs now use a layer of protective material on the surface through which the data is read.
Like many others, I have a digital, â€śHD-readyâ€ť television. The number of HD televisions in the UK is huge and growing, but fewer than 10% of owners can actually watch HD programmes on them. Many of them subscribe to channels such as Sky. Freeview is not the answer, as the technology is not appropriate.
The first titles were only released on Blu-ray in June 2006. The fact that Columbia Pictures and MGM were owned by Sony was a huge, and perhaps crucial, boost. Gradually more and more companies switched their allegiance to the format. What was, perhaps, a fatal blow in the struggle for market share was struck in June 2007, when Blockbuster, the largest chain of video game and DVD rental shops in the world, announced that its next batch of HD DVDs would only be in the Blu-ray format. If films are mostly available in one format, customers will naturally buy the machine for that format.
An example of a patent specification that offers to cater for either format is Warner Home Video's WO 06/071809, published in July 2006.