KELTEK Display Measurement Laboratory -- Home
Back to NIST Publications
REFLECTION METROLOGY

Overview:
The former NIST efforts concentrated on providing robust measurement methods of display reflection ultimately based upon the bidirectional reflectance distribution function (BRDF). We were using a three-component reflection model of specular (with a distinct virtual image proportional to the luminance of the source), Lambertian (perfectly diffuse, luminance proportional to the illuminance), and haze (a diffuse intermediate state of between specular and Lambertian that is peaked in the specular direction but proportional to the illuminance). Discussions of other reflection components encountered in display work should be forthcoming. Note that there can be some nomenclature inadequacies in the older publications, but the genearl ideas may be useful.

Publications:

Robustness of Display Reflectance Measurements: Comparison Between BRDF and Hemispherical Diffuse Reflectance: (SID2009-24p2-SKim.pdf) -- This paper shows how a BRDF actually does compare with a hemispherical diffuse measurement.  Citation: S. Kim, E. F. Kelley, and J. Penczek, "Robustness of Display Reflectance Measurements: Comparison between BRDF and Hemispherical Diffuse Reflectance," 2009-SID International Symposium Digest of Technical Papers, Society for Information Display, Paper 24.2, Vol. 40, pp. 325-327, 2009.

Character Contrast Under Uniform Ambient Conditions (SID2009-24p1-CharCon-EKelley.pdf) -- Character-contrast methods in integrating sphere to account for veiling glare in the detector.  Citation: E. F. Kelley, J. Penczek, and P. A. Boynton, "Character Contrast Under Uniform Ambient Conditions," 2009-SID International Symposium Digest of Technical Papers, Society for Information Display, Paper 24.1, Vol. 40, pp. 321-324, 2009.

Diffuse Reflectance and Ambient Contrast Measurements Using a Sampling Sphere: (ADEAC06_Sampling_Sphere_2-1.pdf) -- To avoid having to try to fit a large display into a large integrating sphere, a sampling sphere may be used to measure the diffuse reflectance of a display. However, there are some subtleties that need attention.  Citation: E. F. Kelley, "Diffuse Reflectance and Ambient Contrast Measurements Using a Sampling Sphere," Proceedings of the Third Americas Display Engineering and Applications Conference (ADEAC 2006), Society for Information Display, Atlanta, GA, USA, pp. 1-5, October 24,26, 2006.

Display Daylight Ambient Contrast Measurement Methods and Daylight Readability: (Daylight_Readability_JSID.pdf) -- Daylight (Sunlight) ambient contrast measurements are calculated from  laboratory measurements of reflection parameters. Daylight is a combination of directed sunlight and diffuse illumination from the sky, ground, etc. Readability is not just a function of ambient contrast.  Citation: Edward F. Kelley, Max Lindfors, and John Penczek, "Display Daylight Ambient Contrast Measurement Methods and Daylight Readability," J. Society of Information Display, Vol. 14, No. 11, pp. 1019-1030, November 2006.

Scalability of OLED Fluorescence in Consideration of  Sunlight-Readability Reflection Measurements: (SID04-OLED-Fluorescence.pdf) -- We show the linearity of OLED flurescence beyond sunlight levels and how laboratory reflection measurements can be scaled to sunlight levels. We provide an example of a sunlight-readability contrast measurement. Citation: E. F. Kelley and J. Penczek, "Scalability of OLED Fluorescence in Consideration of  Sunlight-Readability Reflection Measurements," 2004-SID International Symposium Digest of Technical Papers, Society for Information Display, Paper P.54, Vol. 35, Book 1, pp. 450-453, Seattle, WA, May 25, 2004.

Sensitivity of Display Reflection Measurements to Apparatus Geometry: (SensitivityApparatusGeometry-SID2002.pdf) -- We show how small changes in reflection-measurement apparatus configurations can affect the reflection measurement results--a characterization of robustness. Citation: E. F. Kelley, "Sensitivity of Display Reflection Measurements to Apparatus Geometry," 2002-SID International Symposium Digest of Technical Papers, Society for Information Display, Boston, MA, pp. 140-143, May 19-24, 2002.

Proposed Diffuse Ambient Contrast Measurement Methods for Flat Panel Displays: (Ambient_Contrast_NISTIR6738.pdf) --The measurement of the diffuse reflectance of a display and the contrast under such diffuse illumination is one of the most robust reflection measurements that can be made. A variety of apparatus can be used to obtain essentially the same reflectance value. Citation: E. F. Kelley, "Proposed Diffuse Ambient Contrast Measurement Methods for Flat Panel Displays," NISTIR 6738, 6 pp., April 2001.

The Three Components of Reflection: (IDDM02-ThreeReflectionComponents.pdf) --A tutorial paper introducing the three components of reflection. Citation: E.F.Kelley, G.R.Jones, and T.A.Germer, "The Three Components of Reflection," Informational Display, Vol. 14, No. 10, pp. 24-29, October 1998.

Display Reflectance Model Based on the BRDF: (DisplaysBRDF.PDF) --A paper providing some of the mathematical detail and examples of display BRDFs. Citation: E.F.Kelley, G.R.Jones, and T.A.Germer, "Display Reflectance Model Based on the BRDF," Displays, Vol. 19, No. 1, pp. 27-34, June 30, 1998.

Reflection Measurement Problems Arising from Haze: (SID98ApertureHaze.PDF) --This paper demonstrates that whenever the haze component of reflection is present and non trivial, then the measurement result becomes sensitive to the geometry of the apparatus. Citation: G. R. Jones and E. F. Kelley, "Reflection Measurement Problems Arising from Haze," 1998-SID International Symposium Digest of Technical Papers, Society for Information Display, Vol. 29, pp. 945-946, Anaheim, CA, May 17-22, 1998.

Notes:
1.   Also see the latest seminars or courses here .
2.   Considerable research is being done at NIST on the measurement and applications of BRDFs as well as reflections here.

Updated 20111009T0738