HIGH-DENSITY VIDEO DISC USING SUPERRESOLUTION AND GREEN LASER

Development of a high-density multiple sub-Nyquist sampling encoding (MUSE) video disc with a playback time of 2 h per side has been achieved using an optical head which utilizes the superresolution technique and a green laser, and by quadrupling the recording density of the analogue video disc. The focused spot size of the main lobe in the superresolving direction of the optical head was 0.63 mum (1/e2 full width). With this optical head, using the slit detection method, a carrier to noise (CN) ratio of 56 dB was obtained at a pit length of 0.3 mum which is the cut-off pit length of the 670 nm optical head. Compared with an optical head using only a green laser, the CN ratio at a pit length of less than 0.3 mum was improved by 2 to 3 dB. An SN ratio of 41.5 dB was obtained for the quadruple phi300 mm MUSE video disc which has a 0.8 mum track pitch and a 10.1 m/s linear velocity.