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Sony says it has finally cracked the problem of displaying moving picture
adverts to train passengers travelling through a tunnel (EP 989 535/752).
Previous attempts were disappointing, and relied on the passing windows to act
as a shutter. Sony says the answer is spaced LCD screens which blink images on
and off at a rate which exactly matches the speed of the train. So each
passenger sees a sequence of blinking images on the tunnel wall which blend into
a short movie. The screens only light up when the driver’s cabin has passed, so
there is no risk of the driver watching the movies.