Display Metrology

Television, computers, and telecommunications are merging into advanced digital video and computer systems that will provide new services for education, engineering, manufacturing, robotics, entertainment, medicine, defense, security, transportation, publishing, banking, and government. A critical element in this convergence is that electronic displays are ubiquitous. To facilitate worldwide commerce in displays, well-defined methods for specification and verification of display quality are needed to ensure that a display will work under the necessary lighting conditions. NIST is working with industry standards-developing organizations to ensure such equity in the marketplace by developing the metrology base for displays.

The United States is a major buyer of electronic displays for computer, consumer, automotive, medical, and avionics use. The latter three applications require stringent testing to ensure adequate performance. For example, the medical radiological community requires a display that will provide them with the contrast and resolution that faithfully duplicates their experience with X-ray film with proper diagnoses depending upon it. In addition, well-defined methods for specification and verification of display quality are necessary to enable worldwide commerce of displays. Sound metrology is urgently needed in this highly competitive environment of new and emerging display technologies to ensure quantitative metrics for comparing the performance of emerging technologies. Further, universally recognized and accepted standard documents are needed to provide customers with the necessary tools to use in choosing the best display for their application.

To address these needs, we have focused our efforts on developing a common set of best practices in critical measurement areas. These areas include reflection and veiling glare, and the development of transfer standards to facilitate direct comparisons of different display technologies.

In the area of reflection metrology, we have developed quantitative methods based upon the bidirectional reflectance distribution function. We are 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). We have extended these techniques to address issues related to daylight readability of displays.

• Short course on display metrology, including hands-on laboratory experiments
• Standard metrics for handheld imagers for first responders
• Methods for characterizing luminance probes for use with high-contrast medical displays
• Guide of consumer tips for purchasing flat panel televisions
• VESA Flat Panel Display Metrology Standard, ISO display metrology standard 9241-305, SID International Committee for Display Metrology
• Standard metrics for daylight-readability performance of displays