Ultra Density Optical

Ultra Density Optical is an optical disc format designed for high-density storage of high-definition video and data. The format was introduced by Sony to replace the Magneto-optical disc format.

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Overview

An Ultra Density Optical disc, or UDO, is a 133.35 mm ISO cartridge optical disc which can store up to 30 GB of data. The second generation UDO2 media format was introduced in April 2007 and has a capacity of up to 80 GB. It utilizes a design based on the Magneto-optical disc, but uses Phase Change technology combined with a blue violet laser. A UDO/UDO2 disc that can store substantially more data than a magneto-optical disc. This is due to the shorter wavelength of the blue-violet laser employed. MOs use a 650 nm-wavelength red laser. Because its beam width is shorter when burning to a disc than a red-laser for MO, a blue-violet laser allows more information to be stored digitally in the same amount of space.
Current generations of UDO2 media store up to 60 GB.

History

UDO optical disc storage media was developed as a replacement for the 9.1 GB Magneto-optical digital storage medium. The Ultra Density Optical was first announced by Sony on November 1, 2000. It was later adopted with heavy investment by Plasmon, a UK technology company with extensive experience with computer archival backup systems and solutions.
Currently, UDO/UDO2 is being championed by its development partners Plasmon, Asahi Pentax, Mitsubishi Chemical, parent company of the Verbatim media storage brand, and various computer and IT solutions companies. Mitsubishi Chemical is the second major development partner of UDO media and the sole manufacturer of UDO media as of the 4th quarter of 2008.
On November 10, 2008, Plasmon creditors closed down Plasmon LMS as CEO Stephen 'FX' Murphy was unable to secure funding to keep the money-losing company afloat. The UDO media factory in the UK was shut down and dismantled.
On January 13, 2009, Alliance Storage Technologies, a Colorado Springs Manufacturer of optical technology and Service Provider, acquired the assets of Plasmon in a liquidation sale. ASTI currently sells and supports UDO technologies sold under the Plasmon brand.

Specifications

ECMA-380: Data Interchange on 130 mm Rewritable and Write Once Read Many Ultra Density Optical Disk Cartridges –Capacity: 60 Gigabytes per Cartridge – Second Generation

Writing technology

UDO uses a Phase Change recording process that permanently alters the molecular structure of the disc surface.

Disc format

There are three versions of UDO/UDO media: a True WORM, an R/W, and Compliant WORM.
; Rewritable
; True write once
; Compliant write once media

Magneto-optical comparison

The table below summarizes the differences between conventional Magneto-Optical specifications and those of the enhanced Ultra Density Optical disc.

Disc	5.25-inch UDO Rewriteable	5.25-inch UDO Write Once	5.25-inch MO system
Disc diameter	130 mm	130 mm	130 mm
Disc thickness	2.4 mm	2.4 mm	2.4 mm
Cartridge size	Same as ISO 130 mm	Same as ISO 130 mm	ISO 130 mm
Number of physical tracks	96,964	96,964	49,728
Sector size	8 kB	8 kB	4 kB
Number of sectors	2,504,407	2,504,407	1,118,880
Data area	29.0-61.0 mm	29.0-61.0 mm	29.7-62.5 mm
Designated laser wavelength	Violet	Violet	660 nm
Objective lens	0.85	0.85	0.575
Recording layer	Phase change	Phase change	Magneto-optical
Recording format	Land & groove	Land & groove	Land & groove
Recording side	Both sides	Both sides	Both sides
Track pitch	0.33 μm	0.33 μm	0.65 μm
Minimum bit length	0.13 μm	0.13 μm	0.3 μm
Recording density	15.0 Gb/in²	15.0 Gb/in²	3.3 Gb/in²
Transfer rate	4-8 MB/s	4-8 MB/s	3-6 MB/s
Error correction	LDC	LDC	LDC
Modulation	RLL	RLL	RLL

;Note

Drive mechanism

UDO Drives Specifications Summary

Media Load Time 5 s
Media Unload Time 3 s
Average Seek Time 35 ms
Buffer Memory 32 MB
Max Sustained Transfer Rate – Read 8 MB/s
Max Sustained Transfer Rate – Write 4 MB/s
MSBF – Mean Swap Between Failure 750,000 load/unload cycles
MTBF – Mean Time Between Failure 100,000 hours
Interface Wide Ultra 2 LVD SCSI

UDO comes in both internal and external drive guises. External drives are also available as part a robotic autoloader. All current drives are designed for heavy duty use.

Laser and optics

UDO systems use a blue-violet laser operating at a wavelength of 405 nm, similar to the one used in Blu-ray Disc, to read and write data. Conventional MOs use red lasers at 660 nm.
The blue-violet laser's shorter wavelength makes it possible to store more information on a 13 cm sized UDO disc. The minimum "spot size" on which a laser can be focused is limited by diffraction, and depends on the wavelength of the light and the numerical aperture of the lens used to focus it. By decreasing the wavelength, using a higher numerical aperture, the laser beam can be focused much more tightly. This produces a smaller spot on the disc than in existing MOs, and allows more information to be physically stored in the same area.
The opto-mechanism design of current Plasmon UDO drives was jointly developed with Asahi Pentax.

Applications

Archival storage

Currently UDO has an expected data archival life of around 50 years. Apart from the storage size, the discs are designed for durability and long term reliability.

Secure video

A company called Blu-Laser Cinema announced in June 2005 that it was launching a new player using the UDO format to provide a secure viewing and editing platform for film production houses. Targeted towards the high-end video editing and production community, the unit featured a smart card reader and a USB dongle with an embedded biometric fingerprint reader to allow access only to authorized users.

Features

The core technology for UDO is essentially similar to Blu-ray Discs, as well as PDD, although there are a number of key differences; the primary ones being:
; Data authenticity and integrity
; Long-term data retention
; High capacity and scalability
; Rapid information access
; Low total cost of ownership