Patent ID: 8511884

Claim:
A one-way see-through illumination device comprising: a light guide, the light guide having a front surface and a back surface, there being a predetermined critical angle of incidence at the front surface and the back surface sufficient to establish total internal reflection of light incident at the front surface and the back surface when interfaced with an expected ambient medium; a light source optically coupled to the light guide for injecting light into the light guide at an angle of incidence relative to the front surface and the back surface that is greater than the predetermined critical angle of incidence to promote total internal reflection of the injected light within the light guide; an image pattern comprising a back layer and a front layer, the back layer of the image pattern being a light reflecting material and the front layer of the image pattern being an illuminable material, wherein the illuminable material is bonded to the back surface of the light guide and extracts the injected light from the back surface of the sheet of optical material to illuminate the image pattern for viewing through the front surface of the light guide, wherein the light emitted from the illuminable material is substantially monochromatic; and a color filter positioned behind the illuminable material for selectively absorbing the substantially monochromatic light emitted from the illuminable material that is back-reflected off the front surface of the light guide, the color filter allowing other wavelengths of light to be transmitted therethrough.