Patent ID: 7591094

Claim:
A high dynamic range image display light box, comprising: (a) a light emitting surface having: (i) an inward side and an outward side; (ii) a first portion comprising: (1) a substantial area of the light emitting surface; (2) an intrinsic reflectance value greater than 95%; (3) a first extrinsic reflectance-reducing characteristic giving the first portion a first light transmissivity characteristic of less than 5%, the first light transmissivity characteristic being macroscopically invariant as a function of position over the first portion; (iii) a second portion comprising: (1) the area of the light emitting surface excluding the first portion; (2) a second extrinsic reflectance-reducing characteristic giving the second portion a second light transmissivity characteristic of greater than 25%; (b) a sheet extending substantially parallel to and in close proximity to the outward side of the light emitting surface, the sheet bearing an image having: (i) one or more normal luminance display regions, each normal luminance display region having: (1) the same size and shape as a corresponding segment of the first portion of the light emitting surface; (2) a third light transmissivity characteristic which varies as a selected function of a desired normal luminance characteristic of the image; (ii) one or more high luminance display regions, each high luminance display region having: (1) the same size and shape as a corresponding segment of the second portion of the light emitting surface; (2) a fourth light transmissivity characteristic which varies as a selected function of a desired high luminance characteristic of the image; and (c) at least one diffuse light source on the inward side of the light emitting surface for emitting diffuse light onto the inward side of the light emitting surface; wherein the third light transmissivity characteristic and the fourth light transmissivity characteristic are selected such that the first, second, third and fourth light transmissivity characteristics together impart a high dynamic range to the image when the inward side of the light emitting surface is backlit.