Fumio Tabata

The future of magneto-optical recording

This paper describes next generation technologies and future technologies of MO (Magneto-Optical) recording. A proximity optical head with blue laser, high NA lens and magnetic coil was developed. The head is kept at 30 μm height over media, using new optical feedback system. Front surface recording using the head and media well designed for blue laser achieved recording density of 17 Gb/in2, giving 23 GB/120 mm media. As future technologies, an optical flying head was developed with 3 μm flying height. Combining the head and DWDD media, a density of 40 Gb/in2 or 50 GB/120 mm media will be possible. &#les;

Development of an Isolation Table with an Active Vibration Control Mechanism.

Isolation tables are effective in preventing vibration. If objects on a table move, however, the table starts vibrating at a low frequency, with a large displacement due to the force of the impact. Some equipment on an isolation table cannot be kept at a constant distance from equipment on the ground. To overcome this problem, An active vibration control mechanism based on state feedback control using 4 voice-coil motors was developed. This system could suppress the displacement of the isolation table at 100 μm even if some objects on the table moved.