Electrically controllable light conducting device

Claim 1

Light reflection control means for utilization in information display apparatus including: a. a rod of first light conducting material having a longitudinal dimension, a cross sectional dimension, first and second ends and an outer surface along said longitudinal dimension intermediate said ends, said rod being comprised of a solid formation of said material extending throughout said cross sectional dimension and said longitudinal dimension and presenting a predetermined index of refraction; b. a plurality of individual electrodes positioned closely adjacent said outer surface and extending along at least a portion of said longitudinal dimension; c. second light conducting material intermediate said outer surface and said electrodes, said material being in intimate contact with said outer surface and providing an interface of said first and second materials along said longitudinal dimension, said second material presenting electrically controllable light conducting characteristics; d. means for connecting voltages to said electrodes for establishing a fringe of individual electric fields adjacent the outer surface along said portion of the longitudinal dimension, said fringe of electric fields extending through said second light conducting material to at least the interface of said first and second materials independently of the necessity to penetrate the material of said rod, said second light conducting material being subjected to the influence of said fields for changing the light conducting characteristics thereof and controlling the reflection of light through said control means.