Mais est-ce que vous aviez déjà entendu parlé du VHD et du RCA CED ?
https://en.wikipedia.org/wiki/Video_High_DensityVideo High Density (VHD) is a videodisc format which was marketed predominantly in Japan by JVC. There was also an audio-only variant, Audio High Density (AHD).
https://en.wikipedia.org/wiki/Capacitan ... ronic_DiscThe Capacitance Electronic Disc (CED) is an analog video disc playback system developed by RCA, in which video and audio could be played back on a TV set using a special needle and high-density groove system similar to phonograph records.