Магнитооптический диск MO disk SONY CWO-4800B, 4.8GB, 5.25 in

• Up to Two-thirds Faster Performance Compared to Competing Models
• Advanced Multi-layer Recording Structure for Maximum Performance and Reliability
• Patented Sony Wide Margin Design Compensates for Drive Speed and Power Fluctuations

LIMDOW Model Names
DOW-2300B
DOW-2600B

Sony is MO disks have continually evolved in response to the ever-growing need for higher and higher speeds. The next step in this evolution was taken with the development of a unique direct overwrite method that utilizes a multi-layer magnetic film optical modulation process known as LIMDOW (Light Intensity Modulation Direct Over-Write).

To realize this feat, Sony changed the conventional single magnetic layer structure to a multi-layer one which includes memory, recording, switch and initialization layers and employs an optical power modulation method to achieve direct overwrite. In this approach, recording and erasing functions are performed during high and low power laser irradiation, respectively (see description below). In other words, direct data overwrite is possible by simply varying the laser power from strong to weak.

Until now, three steps were required for data rewrite in conventional MOs: erase, record and verify. However, the LIMDOW method requires only two steps, erase/record and verify, which substantially shortens rewrite time (by approximately two-thirds when compared to Sony is conventional MO).

Sony is Wide Margin Design supports a wide variety of drives and rotation speeds

Recording on an MO disc is accomplished by heating the magnetic layer with a laser and heat magnetism recording by recording electric field. The recording sensitivity of the disc is reduced as the rotation of the disc speeds up due to the fact it becomes more difficult to raise the temperature of the magnetic layer. By optimizing the design of the entire recording layer (see diagram), Sony has been able to suppress these changes in sensitivity; accordingly, this wide margin design supports a wide variety of drives with various rotation speeds.