Masaru Ibuka

If Akio Morita sold Sony to the world, Ibuka was the one who defined what it would make. An engineer by training, he set the challenges behind Japan's first tape recorder, the pocket transistor radio and the Trinitron colour television. The Walkman began with his request for a portable player to listen to music on long flights, which engineers built by adapting the Pressman recorder. He is the clearest case on this list of a founder steering design through precise demands rather than drawing it himself.