Paper
26 April 2002 Etendue efficient coupling of light using dual paraboloid reflectors for projection displays
Author Affiliations +
Proceedings Volume 4657, Projection Displays VIII; (2002) https://doi.org/10.1117/12.463778
Event: Electronic Imaging, 2002, San Jose, California, United States
Abstract
With the introduction of Digital Micromirror Device (DMD) and Liquid Crystal on Silicon (LCOS) technologies, imagers for projection displays become increasingly smaller, thus requiring more intense, focused light with lower etendue values. To illuminate these smaller imagers, a patented dual paraboloid reflector system has been developed to collect and focus light from an arc lamp onto the imager without loss of brightness. This powerful optical platform provides the control and etendue efficiency that has been missing in standard illumination sy stems. The dual paraboloid reflector system consists of two parabolic reflectors placed symmetrically facing each other. The first parabolic reflector collects and collimates it into a parallel beam. The second parabolic reflector intercepts the parallel beam and focuses the light with unity magnification, i.e. 1:1 imaging, into a tapered light pipe (TLP) with conserved brightness. The TLP transforms the focused light into an output with the needed area, shape, and numerical aperture (NA). It also acts as a homogenizer so that the intensity profile at the output surface is uniform and eventually provides a uniform intensity profile at the screen. The reflection of light twice in the dual paraboloid reflector system provides a high IR and UV rejection ratios, resulting in less degradation of the optical components. Polarization and color recycling systems are also designed taking advantage of this reflector configuration.
© (2002) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kenneth K. Li "Etendue efficient coupling of light using dual paraboloid reflectors for projection displays", Proc. SPIE 4657, Projection Displays VIII, (26 April 2002); https://doi.org/10.1117/12.463778
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Cited by 7 scholarly publications.
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KEYWORDS
Reflectors

Lamps

Imaging systems

Liquid crystal on silicon

Polarization

Projection systems

Optical components

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