Blue-Ray Disc

Blue-ray Disc
Once considered, the most demanding devices for storage were, DVDs and CDs, had taken back feed in this era of storing high definition video and big applications. This need of storing high definition video and large data has led to invention of Blue-ray Disc. Blue-ray Disc (also known as Blue-ray or BD) is an optical disc storage media format. Its main uses are in high-definition video and data storage. The disc has the same physical dimensions as a standard DVD or CD. A dual layer Blue-ray Disc can store 50 GB, almost six times the capacity of a double-dual layer DVD (or more than 10 times if single-layer). Philips and Sony started two projects applying the new diodes: UDO (Ultra Density Optical) and DVR Blue (together with Pioneer), a format of rewritable discs which would eventually become Blue-ray Disc (more specifically, BD-RE). The core technologies of the formats are essentially similar. The first DVR Blue prototypes were unveiled at the CEATEC exhibition in October 2000. Because the Blue-ray Disc standard places the data recording layer close to the surface of the disc, early discs were susceptible to contamination and scratches and had to be enclosed in plastic cartridges for protection. In February 2002, the project was officially announced as Blue-ray, and the Blue-ray Disc Association was founded by the nine initial members. The first consumer devices came to stores on April 10, 2003. This device was the Sony BDZ-S77; a BD-RE recorder that was made available only in Japan.

Technical specifications


|Type |Physical size |Single layer capacity |Dual layer capacity |
|Standard disc size |12 cm, single sided |25 GB (23.28 GB) |50 GB (46.56 GB) |
|Mini disc size | 8 cm, single sided |7.8 GB (7.26 GB) |15.6 GB (14.53 GB) |


Laser and optics

Blue-ray Disc...