From the time high definition televisions (HDTV) made its appearance into the market in the year 1998 the demand for high capacity storage DVD has increased. Regular DVDs turned out to be insufficient for this application. DVDs support resolutions up to 720×480 pixels whereas HDTV will work with the resolution of 1920×1080 pixel format. The above definition approximately means that to run a two hour video on a HDTV requires storage capacities of 22GB where as the maximum capacity of the DVDs that are available in the market are 17GB.
This has led for the development of the DVD with higher storage capabilities suitable for HDTVs. This development ultimately resulted in two DVD formats with huge storage capability, one from Sony Corporation called as Blu Rays and other from Toshiba called as HD-DVD with the support from their technology partners. Evolution of Blu Rays: Sony started two new rewritable disc storage systems: ultra density optical UDO and DVR Blue. The first DVR Blue prototype was released in the October 2000 CEATEC exhibition.
In February 2002 the project was officially announced as Blu-Ray Disc(or simply BD) and Blue Ray Disc Association was founded with initial nine members at consortium made by the companies that include Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson. HD-DVD, on the other hand, was created by Toshiba and got support from Microsoft, HP and Intel. The regular DVDs use red laser (wavelength of 650nm) to read and write whereas blu-ray uses a blue-purple laser to read and write data.
As the wavelength is smaller for Blue –purple laser (450nm) this allows for a higher recording density. While recording the blue-purple laser is used to burn pits on the disc surface. The areas that weren’t burnt are known as lands. While reading blue-purple laser with lower intensity is thrown on the disc. When a pit is encountered the light is reflected with a lower intensity compared to the land. This is how a Blu-ray detects pits and lands. The physical dimensions of the Blu-ray are same as the regular DVD. This is from the blue laser that is used the named Blu-Ray has been derived.
On April 10th 2003 the first Blu-Ray devices were released. It was Sony BDZ-S77 a BD RE recorder which was made available only in Japan. The physical dimensions were finalized only ion 2004. In the year 2005 TDK made an announcement that a polymer coating has been developed for the Blu-Ray discs. BD-ROM specifications were finalized in the year 2006. In the year 2004, a consortium is formed which has been developing the DRM platform that is used to securely distribute movies to customers. The first BD-ROM players were released in June 2006. Blu-Rays titles were first released on June 20, 2006.
Initial releases used MPEG-2 video compression similar to DVDs. September 2006 viewed first release of newer VC-1 and AVC codec. First movies using dual layer discs which have storage capacity of 50GHz was released in October 2006. The first mass market for Blu-ray Disc was seen in July 18 2006. The prices are as large around US$699. The Table below shows the Physical dimensions and storage capacity of the BD in comparison with the regular DVD. Competition from HD DVD: A forum was set up in the year 1995 for the exchange of hardware and software updates of the regular DVD.
From the initial stage of the development of blue laser DVD committee has different opinions. In August 2002, Toshiba and NEC made an announcement about their competing standard advanced optical devices. DVD forum finally adapted it and the next year it was renamed as HD DVD. There was though competition between the Blu-Ray and HD DVD. The support from the technology partners from both the sides increased the competition among Blu-Ray and HD DVD. Both Blu-ray and HD DVD have same physical dimensions their storage capabilities and other supporting differences are listed in the tables below. Blu-Ray HD DVD
ROM single layer: 23. 3/25GB ROM dual layer: 46. 6/50GB RW single layer: 23. 3/25/27GB RW dual layer: 46. 6/50/54GB Highest test: 100GB Theoretical limit: 200GB Single layer: Dual layer: – – Highest test: Theoretical limit: 15GB 30GB – – 45GB 60GB 15GB 30GB – – 45GB 60GB Table-1 Comparison of the capacity of Blu-rays and HD DVD Attempts were made to avoid the confusion over the format between Blu-ray and HDDVD in the year 2005. Blu Ray supporters opted for Java Based platform for interactivity where as HD DVD opted for Microsoft’s HDi.
In august 2005 they both disagreed for a common format and the negotiations failed. And by the end of September Microsoft and Intel announced their support to HD DVD. In March 2005 Toshiba released the first HD DVD player months in advance than Blu- Ray. It made its appearance in US market in April 2005 at US$499. The price is small compared to that of the Blu-Ray so as the storage capacity. The difference between Blu-Ray and HD DVD is shown in the table below (Tab-1) and the technology partners of each format are shown in Fig-II.