COPY PREVENTION METHOD AND APPARATUS THEREFOR

摘要

THE INVENTION DISCLOSES AN APPARATUS TO PREVENT RECORDING OF FRAMES ON A SCREEN PROJECTED ONTO THE SCREEN FROM A FRAME SOURCE (10) IN A NON-DISTORTED MANNER BY ANY FRAME RECORDING DEVICE COMPRISING A MEANS TO OBSTRUCT THE BEAM OF LIGHT FRAMES IN A MANNER THAT THE BEAM IS OBSTRUCTED AT A FREQUENCY 50 HZ AND ABOVE. A METHOD OF COPY PREVENTION USING THE PRINCIPLES EMBODIED IN THE ABOVE APPARATUS IS ALSO DISCLOSED.