Press Release

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March 23, 2000

Sharp and Sony Jointly Develop Small Size High Density
Magneto Optical (MO) Disc

March 23, 2000 - Sharp Corporation and Sony Corporation today announced the joint development of a 50.8mm diameter small size high density magneto optical (MO) disc to comply with miniaturization of mobile devices and multiplication of data capacity.

By adopting a super resolution magneto optical system and a 0.5mm thick substrate, the new MO disc can record 1 gigabyte (1GB) with the red laser (655nm wavelength) and more than 2 gigabytes (2GB) with the blue laser (405nm wavelength) on a 50.8mm diameter disc. Utilizing the magneto optical recording system can minimize the deterioration of signals and maintain reliability even with repeated recording and playback. These features enable miniaturization and capacity multiplication of mobile devices such as PDA (Personal Digital Assistant), digital still cameras, video cameras and PC data storage.

In line with the practical application of the new MO disc, we will actively work with other companies to promote the standardization of a MO disc with the blue laser. Moreover we will further discuss the potential for a higher capacity version (more than 4GB with the blue laser and a 65mm diameter disc).

The new MO disc format will be widely promoted. At this stage the following companies have agreed to support the format: Casio Computer Co., Ltd., Fujitsu Limited, IBM Japan, Ltd., Mitsubishi Chemical Corporation, Pioneer Corporation, Royal Philips Electronics of the Netherlands, and TDK Corporation.

<Main Features>

(Physical format)

Recording mediaMagnetically induced super resolution media
Recording methodLaser-pulsed magnetic field modulation
Disc diameter50.8mm
Recording capacity1GB, (more than 2GB)
Laser wavelength655nm, (405nm)
Substrate thickness0.5mm
Track formatLand and groove
ECCReed-Solomon product code

Outside dimension58 X 54 X 4mm
False deletion preventionYes

(Logical format)
File structureUDF(Universal Disk Format) standard compliant
* ( ) is an estimate for the "blue laser" disc to be later standardized.

About Sharp Corporation:
Sharp Corporation is a worldwide developer of innovative products and core technologies that play a key role in shaping the future of electronics. As a leader in liquid crystal displays (LCDs), Sharp offers one of the broadest and most advanced lines of consumer electronics, office equipment and electronic components while creating new network businesses.
For more information, please visit Sharp's Web site at

About Sony Corporation:
Sony Corporation is a leading manufacturer of audio, video, communications and information technology products for the consumer and professional markets. Its music, pictures, computer entertainment operations and on-line businesses make Sony one of the most comprehensive entertainment companies in the world. Sony recorded consolidated annual sales of over $56 billion for the fiscal year ended March 31, 1999. Sony's Home Page URL: