Optical MUSE Videodisc with 120 Minutes of Playback Time on Both Sides

Abstract

A doubled disc recording density is used to produce a high definition videodisc with 120 minutes of playback time on both sides. A MUSE video signal and two kinds of PCM sounds are recorded. A narrower track pitch (from 1.6 μm to 1.1 μm) and a lower linear velocity (from 20 m/s to 14 m/s) is used to produce a higher recording density. Improved optical pick-up resolution is achieved by the employment of a visible laser diode with a wavelength of 670 nm and an objective lens with a numerical aperture value of 0.55. Signal parameter examination is used to increase the signal to noise ratio of playback signals.
These technologies applied an injection-molded disc with a fine playback image.