|Disc-shaped recording medium
|Sept. 14, 1993/ Aug. 19, 1991
|Tsurushima; Katsuaki, Yoshida; Tadao
|First proper MiniDisc patent (chronologically); covers recording of compressed audio on an enclosed disc. Borrows heavily from US05243588.
|A disc-shaped recording medium for storing compressed audio data which have been recorded thereon by an optical recording apparatus. The inner diameter of a data recording region of the disc-shaped recording medium is in the range from 28 mm to 50 mm. The outer diameter of the data recording region is in the range from 58 mm to 62 mm for an inner diameter of 28 mm, and is in the range from 71 mm to 73 mm for an inner diameter of 50 mm. The disc-shaped recording medium may be used with a small-sized portable disc recording and reproducing apparatus, and can record compressed audio data for playback with a playback time substantially as long as that of a standard compact disc having 12 cm diameter.