11.3: Sensitivity of Display Reflection Measurements to Apparatus Geometry

Abstract

1Reflection measurements made upon electronic displays can suffer from non-reproducibility owing to their possible strong dependence upon apparatus geometry. The geometrical dependence arises from non-Lambertian diffusion properties. We show the inadequacies of several conventional reflection measurement methods and offer some guidance on how these methods might be improved or replaced.

24.2: Robustness of Display Reflectance Measurements: Comparison between BRDF and Hemispherical Diffuse Reflectance

“…In previous investigations on display reflectance measurements, we have determined that the hemispherical diffuse reflectance measurement performed with an integrating sphere is the most robust, reproducible and unambiguous direct measurement among the conventional methods used to characterize display reflection. [3] In this paper, we present the measurement results obtained by use of a high-resolution in-plane BRDF apparatus and show the agreement of the hemispherical diffuse reflectance values calculated from the BRDF data with those measured by the use of integrating spheres. [4] 2.…”

Broadband cholesteric liquid crystal devices with poly(N-vinyl carbazole) microstructures

“…The conventional reflection measurements are sensitive to apparatus geometry and a reliable result cannot be easily obtained, [13] so the transmission spectra rather than reflection spectra were measured in our experiment. The transmission spectra T(λ) of the CLC cells were measured using diffused light produced by a 10 cm diameter integrating sphere as shown in Figure 1.…”

Current projects in display metrology at the NIST flat panel display laboratory

“…The haze parameters are particularly difficult to measure, for the measurement can be sensitive to the geometry of the apparatus [2]. Thus, such parameters as the LMD distance, lens diameter, focus, source size, and source distance come into play.…”

“…In the past, the NIST DMP has established diagnostics and tools to address such issues as reflections [1,2], stray light [3] and color accuracy [4], and has supported the development of display standards [5,6].…”