Professional Disc
From Wikipedia, the free encyclopedia
Professional Disc (PFD) is a recordable optical disc format introduced by Sony in 2003 primarily for its new tapeless recording system, XDCAM. It was one of the first two formats (along with Ultra Density Optical) to utilize blue-violet lasers for reading and writing, which allowed for much higher density data to be stored on optical media compared to the longer wavelength infrared laser technology used in the CD and red laser technology used in the DVD format.
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[edit] Technology
PFD uses a 405 nm wavelength and a numerical aperture (NA) of 0.85 for the laser, allowing 23 GB of data to be stored on one 12 cm disc – the equivalent to nearly five single-layer DVDs, and a 1x speed data transfer rate of 88 Mbit/s for reading and 72 Mbit/s for writing. Since the 23GB disc was released a dual-layer 50 GB has been developed and been released.
Confusingly, this sounds very similar to the Blu-ray Disc format, another optical disc format using blue-violet lasers which is also supported by Sony. Even the PFD's caddy and Blu-ray's bk prototype caddy (later it was dropped) looked very similar. The only apparent difference is that single-layer PFD discs have a capacity of 23 GB whereas Blu-rays can store 25 GB. However, Blu-ray Discs currently allows a 2x data transfer rate of 72 Mbit/s – lower than PFD. This is because PFD discs use much higher quality media and drives use higher quality components, making them prohibitively expensive for the average consumer segment to which Blu-ray Discs are aimed.
[edit] Applications/products
[edit] XDCAM video system
The PFD format is used as the recording medium in Sony's XDCAM professional video devices, both for standard definition and high definition applications.
[edit] Professional Disc for Data (PDD)
Professional Disc for DATA (PDD or ProDATA) was a general-use recording media variant of PFD, aimed primarily at small and medium-sized enterprise for data archival and backup. PDD drives and media became available in mid-2004. The BW-RS101 external SCSI-3 drive originally retailed in the UK at £2,344 (excl. VAT) directly from Sony, and 23 GB write-once and re-writeable media retailed for £30 each. Two other drives – the BW-F101/A internal SCSI drive and the BW-RU101 external USB 2.0 drive also became available around the same time.
On March 31 2007, Professional Disc for DATA reached their "end of life".[1] PFD are still being manufactured and used in Sony XDCAM devices. Sony states that PDD and PFD media are not compatible, but does not specify the exact differences between products.
Sony's PDW-U1 Professional Disc drive is an external drive that connects via USB 2.0 to Windows or Mac OS X computers using Sony's freely included software. In a firmware and software upgrade in late July 2009, Sony added the ability for computer users to store any computer files on the Professional Disc. http://forums.creativecow.net/thread/142/866275#866289
