High Density Video Disc Using Superresolution And Green Laser

In order to achieve higher definition, longer playing and smaller disc diameter optical video discs, it is essential to improve recording density. It is reported that making wavelength shorter by using SHG and adopting super resolution technique are effective means to accomplish this. As for high density optical disc system using short wavelength SHG green laser, few reports on 90-minute MUSE disc system has been made.2>³> It is our subject in hand to develop a single sided High-Vision disc with a diameter of 300mm which can play for 2 hours, or a CD size double-sided NTSC disc with a diameter of 120mm which can play for 1 hour per both, as one of our product targets. This paper describes the optical head using super resolution and green laser, and the high density video disc with 2 hours of playback time per side.