I was told that the inventor came up with the idea while at the theatre with his wife. As the spotlights converged on a performer, the idea sprung to mind, and

I was told that the inventor came up with the idea while at the theatre with his wife. As the spotlights converged on a performer, the idea sprung to mind, and he yelped "I've got it!" Quite possibly embellished, but plausible that should be the inspiration.