OPTICAL RECORD SHEET AND DEVICE FOR REPRODUCING SOUND THEREFROM

摘要

An optical sound track is formed in multiturn spiral arrangement on one surface of an opaque sheet-like medium. On the opposite surface some information relating to the sound intelligence recorded on the other surface may be visually represented. For reproduction, the record sheet is placed on an optical sound reproducer with its sound track in face-to-face registered relationship with a turntable on the top surface of the reproducer. A photoelectric reproducing head positioned below a radial slot of the turntable is made to follow the spiral path of the sound track by the resultant of its own linear motion along the slot and the rotation of the turntable relative to the record sheet.