A full N-key rollover capability information entry device includes first and second sets of intersecting light guides oriented at an angle to one another which may comprise a mesh of waveguides that together form a self-supporting planar sheet of a substantially transparent material at the wavelength of light introduced into one end of at least one of the first and second sets of light guides. This permits each intersection to comprise a common portion of both a light guide of the first set and a light guide of the second set that intersect at that intersection. Detection of changes in the intensity of the light in at least one of the sets of light guides in response to key actuation that blocks a portion of the light at a certain intersection is indicative of that actuated key.