8 May 1997 Diffractive projection displays
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Displays based on diffraction effects can provide very high lumen output at high contrast ratio, due to the absence of polarizers, low losses, large-area light valves, and bright light sources. The electron-beam addressed oil-film diffracting light valve employed by the Eidophor is an expensive technology. Recent developments in diffraction form liquid-crystal devices, micromechanical gratings, and elastomeric deformation, could result in a low-cost high- efficiency projector. Therefore, it is of interest to examine the performance limitations of diffractive systems in general, and in relation to other systems. The throughput efficiency of a projector is related to the light source collimation required to transmit light through the limiting apertures of the system. A diffractive device expands the optical divergence, and consequently sacrifices system optical throughput. If the source collimation is increased by the availability of short-arc lamps, or laser diodes, the diffractive throughput penalty is reduced or eliminated. The performance of micromechanical and liquid-crystal diffractive structures is analyzed using a realistic arc lamp model. Theoretical limitations on projector throughput and contrast ratio are derived for diffractive systems, and compared with polarization dependent liquid crystal systems.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
David Armitage, David Armitage, } "Diffractive projection displays", Proc. SPIE 3013, Projection Displays III, (8 May 1997); doi: 10.1117/12.273864; https://doi.org/10.1117/12.273864


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