A tape-shaped switch (500) is provided on a base part (410). Coil springs (460) support a ring-shaped rotational drive section (450) on the position opposed to the switch (500), biasing the same away from the base part (410), so that the rotational drive section (450) may move toward and from the base...http://www.google.de/patents/US7269103?utm_source=gb-gplus-sharePatent US7269103 - Switch device, data-processing apparatus and playback apparatus
