| 摘要 |
The light emitting surface of an image display light box is formed of multi-layer optical film having a reflectance greater than 95% and preferably about 99% or greater. This more efficiently utilizes light rays emitted by the light box's internal light source, since the multi-layer optical film reflects the light rays many times before the rays are absorbed and lost. Consequently, the light emitting surface can have a light transmissivity characteristic which is macroscopically invariant as a function of position on the light emitting surface. Light boxes utilizing prior art reflective materials require cumbersome, time-consuming, iterative trial and error techniques which must be customized for each light box in order to compensate for light absorption losses by imparting a variable transmissivity characteristic to the reflective material.
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