The Evolution of Blu-ray: How The Blu-ray Disc Was Born

Copyright (c) 2008 Titus Hoskins

By now, you have probably heard of Blu-ray or Blu-ray discs and players, but do you know how this high definition technology came to be born or developed? It's a fascinating story, with some major battles thrown in for good measure, a story that is well worth reading even if you're not a tech junkie.

In order to truly understand Blu-ray, you have to go back to the early 80's when CDs or Compact Discs were introduced. CDs were a giant leap forward if you compared it to the current media at the time; mainly because the CD offered more storage, better sound quality and quickly became the universal standard for pre-recorded, recordable and rewritable media. CDs had around 650MB of storage capacity which was revolutionary at the time for data storage and retrieval.

However, no technology stands still, especially when you consider our insatiable need for more compact storage and higher quality images. Hence, we had the introduction of the DVD in the 90's which had a 5-10 X increase in capacity over the CD. The DVD allowed for high quality, standard definition video distribution and recording, not to mention accommodating larger data application. Another key element to this seamless transition, was that the DVD spec used the same factor as the CD which allowed for full backwards compatibility. These key factors would not be lost on the development in the next generation media; this being the Blu-ray Disc. The beginnings of the Blu-ray started in the mid '90's with the introduction of HDTV sets. Consumers soon realized there was no media capable of recording or playing back High Definition content. There were no mediums that could store HD codecs, with the exception of JVCs Digital VHS and Sony's HDCAM; but nothing practical like the CD and DVD media.

However, it was known that using lasers with shorter wavelengths you would be able to create optical storage with higher density. With this knowledge, Shuji Nakamura invented practical blue laser diodes. Its commercial use was delayed by a patent lawsuit, but eventually the Blu-ray disc became available and the next step in the evolution of storage media began.

The Difference: The benefits of Blu-ray Discs versus DVDs.

Although blu-ray disc are the same physical size of a DVD or CD, they are capable of storing and reading much more data. The reason behind this is its use of a blue laser as opposed to the red laser used by DVDs and CDs. The blue laser has a shorter wavelength, a smaller aperture lens and a thinner cover layer on the disc that makes it possible to create a smaller beam spot size capable of storing and reading much more data on the disc.

Of course, no discussion would be complete without mentioning the very heated battle between the two opposing technologies: Blu-ray vs HD-DVD. Each disc format have major backers, behind Blu-ray stands Sony, Dell, Hitachi, Hewlett-Packard, Panasonic, Pioneer, Philips, Samsung... and backing HD-DVD we have Toshiba, NEC and some major movie studios Universal Studios, Paramount Pictures, Warner Bros and New Line Cinema.

While many believe Blu-ray has won the battle and will probably become the dominant high definition technology. (Beta anyone?) The main argument being storage space, since Blu-ray offers 25 GB for single-layer and 50 GB for dual-layer; this is compared to HD-DVD which gives 15 GB for single-layer and 30 GB for dual-layer.

This is Blu-ray's strongest playing card, a single layer Blu-ray disc can hold 25 GB of data. This is compared to the 4.5 GB on a standard DVD. As mentioned before, a dual layer Blu-ray disc can hold 50 GB. This amount of storage allows the disc to capture a full 1080p High Definition image. It has a resolution of 1920 by 1080 progressively scanned pixels. A standard DVD has 720 by 480 pixels. Another benefit of the Blu-ray disc is it has a much wider bandwidth than a DVD. It can produce signals at speeds up to 48 Mbps. This is 6 times quicker than DVD's 8 Mbps.

Furthermore, remember your old DVD's will not be obsolete, as Blu-ray players can play DVD's. Blu-ray players can upscale regular DVD's standard definition images and convert them to a higher resolution which is needed on a HDTV. This process greatly increases picture quality, although it doesn't actually increase resolution. The quality of the players up scaling function is often the determining factor in the quality of the image that is converted.

Considering all these points and features, the future of Blu-ray looks very bright indeed. Blu-ray discs and players will probably be around for quite some time or until another more advanced technology takes its place! But for now, we can all fully enjoy the superior performance and visuals Blu-ray offers us.