<title>Laser-based SXGA reflective light valve projector with E-cinema quality contrast and color space</title>

Abstract

Laser light sources present many advantages for projection displays over the currently employed incoherent light sources. Perhaps the most significant attribute is the laser's high degree of polarization, which greatly improves the efficiency of liquid crystal light valve (LCLV) projectors. The maximum achievable efficiency of an LCLV projector is severely limited with the use of an unpolarized light source such as an arc lamp. The polarized emission from a laser can be coupled to the screen much more efficiently, offering the possibility of smaller projectors with higher luminous efficacies. Additionally, the RGB primaries of laser light fall along the spectrum locus of the chromaticity diagram allowing for a much expanded color gamut over dichroically-separated lamp spectra. This provides the possibility of offering unprecedented color reproduction for the emerging digital cinema industry. The combined properties of polarization, monochromaticity, and low divergence result in a significant increase in image contrast when coupled to LCLV image engines. Substituting lasers for lamp light sources have shown to increase sequential contrast by as much as five-fold. This simple substitution has also resulted in broad improvements to the projector's entire MTF, thereby increasing the apparent resolution of the image. These are all striking arguments as to the potential of lasers in the emerging e-cinema market and the impetuous behind our current development effort presented here.

21.3: D‐ILA™ Technology for Electronic Cinema

“…The full visible spectrum sources -diode pumped solid state lasers -have been used as the illumination light source for a projector using the 23mm SXGA D-ILA image modulators. 8 The results showed a sequential contrast ratio of 1330:1 and increases of 2-5 times in the modulation at high spatial frequencies in the projected images. The color gamut area was twice as large as the SMPTE 240M color space and actually two-thirds the total area inside uniform color space spectrum locus.…”

34.3: D‐ILA™ Device for Top‐End Projection Display (QXGA)

“…These lasers show full-color visible performance with greatly improved electrical-to-light efficiencies with D-ILA [9].…”