Projection displays: New technologies, challenges, and applications

Abstract

-The achievable color gamut and light output of projection displays based on light-emitting diodes (LEDs), phosphor conversion, and lasers are discussed. The color appearance phenomena, colorfulness, and the Helmholtz-Kohlrausch effect are discussed in the context of LED and laser illumination of projection displays, as well as some pitfalls concerning the interpretation of the HelmholtzKohlrausch effect. Also the laser speckle phenomenon and the characterization of it are addressed. The importance of both the American National Standards Institute (ANSI) contrast and the sequential contrast of projectors, as well as the discrepancy between measured and perceived contrasts, are explained. Visibility criteria for contouring artifacts are explained and compared with new emerging electro-optical transfer functions that are more adapted to this issue. Stereoscopic solutions and early prototypes of autostereoscopic multi-view, super multi-view projection displays, and electroholographic displays are discussed as well as the limiting factors of these systems in the context of display resolution, and LED and laser light sources.

Color Conversion Materials for High‐Brightness Laser‐Driven Solid‐State Lighting

“…Laser‐based illumination system thus has been considered to be a compelling source for future SSL. It has advantages of i) high luminance, ii) compact size, iii) directional emission, and iv) very small ètendue (readily captured and focused) …”

β‐SiAlON:Eu2+ Phosphor‐in‐Glass Film: An Efficient Laser‐Driven Color Converter for High‐Brightness Wide‐Color‐Gamut Projection Displays

“…As known, the lighting source is the core component in projector, with the produced light transmitted to imager module for display of a color image on screen, whose optical performance always determines the system efficiency and imaging quality. [ 1–3 ] For a long time, the projectors assembled with xenon or high‐pressure mercury lamp dominated the commercial market; however, these lamps suffer from a mass of deficiencies including limited lifetime, UV/IR irradiation, relatively low luminous efficacy, large étendue value, and slow response to electric switch. [ 4,5 ] In looking for ideal lighting source, the era of solid‐state lighting opens up, stimulating the replacement of projectors’ lamp by light emitting diode (LED) or laser diode (LD).…”

“…[ 17 ] To improve the thermal resistance property of glass, it is preferable to cosinter the β‐SiAlON:Eu 2+ PiG on the sapphire plate with thermal conductivity of ≈30 W m −1 K −1 as thick film. [ 2,19–21 ] Up to date, reports on such kind of PiG film‐on‐sapphire composite material are few; and the in‐depth studies on improving luminescent properties via glass composition optimization, probing the local effect of laser–matter interaction, as well as, constructing ALPD prototype device to evaluate its availability, remain untouched. These are just what we are concerned in this work.…”

An Adaptive Quantizer for High Dynamic Range Content: Application to Video Coding

“…Where V is the normalization of codeword i and V ∈ [0, 1]. When the codeword varies from i to (i+1), the minimum reproducible contrast is defined in Equation (3) [22]. [7].…”