Viewing screen formed using coherent light

摘要

A viewing screen for incident light including a sheet of embossable material in which a first micro-sculpted surface relief structure that controls the direction in which light propagates has been formed by replicating in the sheet of embossable material a second micro-sculpted surface structure that controls the direction in which light propagates, the second micro-sculpted surface structure having been formed in a photosensitive medium having a refractive index by (i) generating random, disordered and non-planar speckle in the photosensitive medium with coherent light which has been diffused through a holographic diffuser so as to define non-discontinuous and smoothly varying changes in the refractive index of the photosensitive medium which scatter collimated light into a controlled pattern with smooth brightness variation and (ii) developing the photosensitive medium, the incident light being incident on and returned from the viewing screen to a viewing area, the viewing screen controlling the direction of the incident light that is emanating from the viewing screen to the viewing area and increasing brightness in the viewing area relative to an area outside the viewing area.