Toru Sekiguchi

Development of noncompressed NTSC digital video disk recorder: I

A digital video disk recorder which can record noncompressed NTSC digital video signal and 4 channel digital audio signals for 32 minutes has been developed. Using (phi) 30 cm magneto-optical (MO) double-sided disk, 23 GB recording data capacity and 123 Mbps high recording bit rate were performed. In order to realize high density and large capacity recording, we have improved optical heads, recording media and others, especially we have developed the new recording method called CWL_CAV (Constant minimum Wave Length - Constant Angular Velocity.

High-performance magneto-optical recording for video file applications

The performance of a digital video file with 113.6 Mbps high data rate, using the duo-binary code, a 200 mm diameter magneto-optical disks and improved servo circuits, is described. Analog and digital recording are compared and a digital composite recording format is selected in order to obtain high quality video images. High density duo-binary recording code, a Magneto-optical disk with double recording layer structure and servo circuits with error integration memories are applied. 55 dB video S/N ratio at 6 MHz bandwidth, bit error rate lower than 10-7 and 2.6 minute recording time are accomplished with 0.46 μm minimum bit length.