TDK today announces it will begin shipments of two new BD-R (write-once type) Blu-ray discs, capable of recording at 4x speed. A single-side, single-layer (25GB capacity) type will be launched at the end of July 2007 and a single-side, dual-layer (50GB) type will be available from August 2007.
TDK's new 4x BD-R discs record in less than half the time of the previous 2x BD-R discs, making the high-capacity optical discs even more efficient. This reduces the time required to copy 4.7GB, equivalent to a single-sided, single-layer DVD-R, to less than five minutes. This recording speed is equivalent to a DVD-R with 16x recording (177Mpbs max. transfer rate). It takes just 22 minutes to record 25GB of user data to a 4x BD-R.
The new TDK 4xBD-R discs, like their predecessors (BD-R) with 1x - 2x capability, have a dual-layer structure. The recording layer is a copper and silicon-based alloy which is unaffected by exposure to light, giving it outstanding archivability. The new discs also adopt TDK's DURABIS2 hard-coating, cover layering technology (formed by high-precision spin coating), and other original TDK technologies, enabling the creation of high-reliability discs.
TDK was the first to market bare Blu-ray disc media – revolutionary single-sided discs that are cartridge free thanks to the unique TDK DURABIS2 protective hard-coat finish. With single-layer 25GB and dual-layer 50GB products now available, TDK is continuing to drive forward the frontiers of next-generation media. In 2006, TDK unveiled BD prototypes with 6x recording capability and 6-layer discs boasting 200GB capacity.
The BDA (Blu-ray Disc Association) has approved the new 4x write-once type Blu-ray Discs, paving the way for their commercialisation.
Main features of the 1x - 4x recording speed compatible BD-R (write-once type) Blu-ray Disc for Data:
- 1. 4x recording compatible. Reduces recording time by half compared with previous 2x disc.
A recording layer boasting high sensitivity and a wide recording margin is utilised for compatibility with 4x recording (144Mbps transfer rate). 4x recording reduces recording time by half compared with the previous 2x disc. This reduces the time required to copy 4.7GB, equivalent to a single-sided, single-layer DVD-R, to less than 5 minutes, a recording speed that is equivalent to a DVD-R with 16x recording (177Mpbs max. transfer rate).
- 2. Use of DURABIS 2 coating designed for bare (cartridge-less) Blu-ray Discs provides significantly greater resistance to scratches and dirt (particularly fingerprint smudges), ensuring safe use even without a cartridge.
Since the area of the laser spot on the Blu-ray Disc is small (about one-fifth that of the DVD), scratches or dirt on the recording surface can have a much more severe effect than on DVDs, causing interference with the irradiation of the laser beam and, in worst cases, even loss of irreplaceable data. For the BD-R's recording surface, the DURABIS 2 coating specially developed for the bare Blu-ray Disc is utilised. Along with significantly higher resistance to scratches, it is also extremely resistant to dirt (particularly fingerprint smudges), ensuring safe use even without a protective cartridge.
- 3. Original high-precision spin coating creates a cover layer with nano-level smoothness, realising stabilised recording and playback.
The Blu-ray Disc is constructed of a 1.1mm thick substrate with a 0.1mm thick cover layer. For the laser beam to penetrate the cover layer to the recording layer, the cover layer assumes the function of a lens, so to speak. For this reason, in the Blu-ray Disc, which uses a blue-violet laser with significantly shorter wave length, the precision and smoothness of the cover layer, from the standpoint of accurate laser irradiation, is extremely important. To form this cover layer, TDK utilises an originally developed high-precision spin coating. The thickness precision is controlled at the nano-level, and an outstanding cover layer with extreme smoothness is formed. As a result, the load on the focus servo circuit used to correct laser beam position is reduced, making possible more stabilised recording and playback.
- 4. Recording layer utilising inorganic material in a metal, dual-layer structure is unaffected by exposure to light, giving it outstanding archivability.
Previous types of write-once type discs such as the CD-R, DVD-R and others utilised organic dye for their recording layer. The BD-R write-once type is based on a completely new concept for the recording layer utilising a two-layer structure composed of silicon (Si) and copper alloy (Cu) inorganic materials. When heated by the recording laser beam, these melt and the Si and Cu alloy become a composite forming recording marks. Because the material is inorganic, it is not affected by light, thus realising a disc with outstandingly high reliability in terms of archivability.
Comparison of times required for recording entire disc (25GB: CLV recording)*
- 1x 90 min.
- 2x 45 min
- 4x 22 min.
*Recording times represent theoretical values (TDK research)
About TDK
TDK Corporation is a leading global electronics company based in Japan. It was established in 1935 to commercialise “ferrite,” a key material in electronics and magnetics. The company today is a leader in the development of next-generation technologies such as Blu-ray Disc recording media, an optical disc ideally suited for high-definition video recording. TDK offers a full line of recordable DVD and CD media, digital camcorder tapes, professional data storage solutions and much more.
