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Press Release


The following information is true and accurate at the time of publication.

November 1, 2000



Sony Develops Next Generation Optical Disk Storage System For the Data Server Market
"5.25-inch Ultra Density Optical (UDO) Format"Realizes 40GB of Capacity

Sony Corporation today announced the development of an optical data storage system, provisionary named the "5.25-inch Ultra Density Optical (UDO) Format", with more than 40GB of recording capacity. Sony is positioning the UDO format as the successor to the Magneto-Optical (MO) disk system, and will now work to finalize the format by the spring of 2001 for product launch in late 2002.

Sony has been actively involved in the development of rewritable data disks, beginning with the 5.25-inch MO disk system (650MB) in 1988. Since then, Sony has doubled (1.3GB) the capacity in 1993, quadrupled it (2.6GB) in 1996, octupled it (5.2GB) in 1988, and is now working to develop 9.1GB system at 14 times the original capacity.

MO systems have gained popularity in the data storage market for features such as random access, high transfer rate, large capacity and long term reliability. In addition to PCs and workstations, MO systems are widely used to store data for LAN/Web servers and for storing medical image data and official public documents. In 1999, 120,000* units of the 5.25-inch MO system were shipped globally (Source: IDC report).


In anticipation of the ever-growing size of digital data in the network era, the market is now requesting an even higher capacity disk storage system with the 5.25-inch form factor. This is especially the case for data servers used for archival purposes, where large volumes of data must be quickly accessed and transferred.

In light of this market demand, Sony decided to develop the "5.25-inch UDO format," a next generation storage system based on a high density optical disk technology. By utilizing violet laser at 405nm wavelength and a land-groove recording system, the new format realizes 40GB of recording capacity. Dimensions of the external cartridge are the same as the current 5.25-inch MOs, which will facilitate future upgrades and expansions of the library systems. Sony is also developing a "Write Once Media Format" for archiving official public documents.

Sony will actively promote the "5.25-inch UDO format" as the optical disk storage system that offers a high capacity storage solution for data servers. In the future, development efforts will be undertaken to further increase the recording capacity to 80GB and 120GB.



Specifications of the "5.25 inch UDO Format"


5.25-inch UDO Format5.25-inch MO
system (9.1GB)*under development
RewritableWrite-Once
Disk Diameter130mm130mm130mm
Disk Thickness2.4mm2.4mm2.4mm
Cartridge SizeSame as ISO 130mm (135 x 153 x 11 mm)Same as ISO 130mm (135 x 153 x 11 mm) ISO 130mm
(135 x 153 x 11 mm)
Number of physical tracks96,96496,96449,728
Sector size8KB8KB4KB
Number of sectors2,504,4072,504,4071,118,880
Data area29.0-61.0mm29.0-61.0mm29.7-62.5mm
Laser wavelengthViolet (405nm)Violet (405nm)660nm
Objective lens (NA)0.850.850.575
Recording layerPhase changePhase changeMagneto Optical
Recording formatLand & GrooveLand & GrooveLand & Groove
Recording sideboth sidesboth sidesboth sides
Track Pitch0.33um0.33um0.65um
Minimum bit length0.13um0.13um0.3um
Recording density15.0 Gb/inch215.0 Gb/inch23.3 Gb/inch2
Transfer rate4-8MB/sec4-8MB/sec3-6MB/sec
Error correctionLDCLDCLDC
ModulationRLL (1,7)RLL (1,7)RLL (1,7)


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