High-uniformity limited-spread point spread function light emitter

摘要

Simple yet powerful mathematical solutions are provided for producing a minimally-spreading de-pixelization light spread function with four-fold bilateral symmetry to create a High Dynamic Range LED-LCD display where the point spread functions of each LED regardless of intensity can be designed such that adjacent rows and columns of LEDs within an array blend smoothly and uniformly to create a non-pixelated continuous image in two dimensions on the diffuser screen and with minimal luminance overlap to minimize the computational demands required at video rate of an HDR display. The resulting image has substantially visually perfect uniform luminance, linear luminance and quadratic luminance gradient. Additionally a new display architecture is unveiled and described that emulates the mathematically developed light spread functions mentioned. This new architecture comprises several sub-aspects to tune the display device to the desired design requirements.

主权项

1. A light distribution system to produce a smoothly varying Lambertian luminance output on an output surface that emits light in a frontward direction towards the viewer, in one or more directions perpendicular to the frontward direction to form a two dimensional array of unit cells, each unit cell comprising:
a. a rear optical cavity further comprising:
i. one or more electric light sources,ii. a rear surface with transmission less than about 5% and reflectance greater than about 70%,iii. a plurality of side surfaces with transmission less than about 5% and reflectance greater than about 70%,iv. a front Lambertian transmission surface having absorption less than about 20% and a Lambertian angular distribution for the transmitted light, wherein the front Lambertian transmission varies according to a predetermined transmission function T(x,y) having a four-fold bilateral symmetry in a square unit cell array or a six-fold bilateral symmetry in a hexagonal unit cell array to substantially match the symmetry of the unit cell array and wherein x and y) are measured from the center of the front Lambertian transmission surface; b. a baffled diffusion cavity adjacent the rear optical cavity, the baffled diffusion cavity further comprising:
i. an optically clear medium in an interior region of the baffled diffusion cavity, the interior region of the baffled diffusion cavity defining a space having a thickness of about 30% of the width thereof, andii. a baffle with an optical transmission rate of less than about 5% located on each of the four sides of the baffled diffusion cavity, with at least one baffle having a thickness of about less than about 10% of the width of the cavity; and c. a non-baffled diffusion cavity adjacent to the baffled diffusion cavity, the non-baffled diffusion cavity further comprising:
i. an optically clear medium, with a thickness of about 30% of the width of the cavityii. a front Lambertian light output surface having absorption less than about 20% and which by means of diffusion within the front Lambertian light output surface achieves a Lambertian angular distribution for the transmitted light and wherein the transmission percentage exceeds at least about 30% wherein the transmission function T(x,y) is predetermined by a deterministic ray trace or an experimental optimization to minimize the visual perception of dis-uniformity arising from the combination of dis-uniform light output, dis-uniform linear gradient light output variation, and dis-uniform quadratic gradient light output variation; and wherein the baffled diffusion cavity includes baffles with a first inner diffuse reflector layer and a second outer retro-reflective layer.