Sony's incredible disc-playing car
n Sony’s glory days, the company’s HQ in Japan used to hold an annual competition for its engineering staff.
Just before the launch of CD in 1982, the golden prize went to Yoshihisa Mori, Director of the Audio Research Labs then working on gramophone pick-ups.
In his spare time, Mori was President of Japan's VW Beetle Owners Club. He had put his two interests together, and built a battery-powered model VW with a tiny amplifier and loudspeaker inside and a gramophone pick-up on the underside.
When placed on an LP gramophone record, the car ran round the record in ever-decreasing circles, guided by the pick-up stylus as it tracked the spiral groove. The speaker played the music.
Sound quality was hardly hifi, but surprisingly good because Mori's car circled the disc at a constant 33.3 rpm. This was more difficult that it sounds. The drive motor had to change speed continuously as the car moved from the long laps at the outer edge of the disc to the shorter laps near the centre. It did this by measuring the angle between the pick-up and the groove spiral.
Sony did not manufacture the car, saying "We are not a toy company", but later licensed it to a toy manufacturer. The idea was soon dropped though and Yoshihisa Mori went on to work on advanced digital audio recording technology. He continued to run the Japanese VW Owners' Club, but never did make a model VW that ran round a CD, playing it with a laser beam.