2020 - today

Measuring the tristimulus values of LED-based light sources can be considered as measurement problem with a multidimensional output quantity. Thus a complete statement of measurement uncertainty of tristimulus values includes a declaration of the correlation between the individual coordinates. Furthermore, by calculating tristimulus values, correlations in-between the tristimulus values are introduced. However, these correlations are naturally taken into account when using the Monte-Carlo approach for measurement uncertainty evaluation.

The alignment quality and reproducibility in ILMD (Imaging Luminance Measurement Device) based display metrology has a great influence on the reproducibility of the obtained measurement data. In this context, this contribution outlines and introduces several advanced measurement and alignment concepts that can be performed with “photometric robotics.” The term describes machine vision performed with an ILMD supported by robotic movements.

The increasing display sizes and changing form factors of displays, including automotive displays, lead to impractical measurement distances for lateral uniformity measurements. This contribution suggests and exemplarily applies two alternative and combinable methods to allow lateral uniformity measurements at low distances and describes an adjusted BlackMURA compliant validation procedure. The proposed methods are validated with a high-quality display device and are compared to results using the standard long-distance measurement procedure.

The increasing display sizes and changing form factors of displays, including automotive displays, lead to impractical measurement distances for spatial uniformity measurements. This contribution suggests and exemplarily applies two alternative and combinable methods to allow spatial uniformity measurements at low distances and describes an adjusted BlackMURA complaint validation procedure. The proposed methods are validated with a high-quality display device and are compared to results using the standard long-distance measurement procedure.

Standardization of measurements is crucial for comparing measurement results. Here, three authors from TechnoTeam describe the steps needed for the standardized evaluation of image-resolved luminance measurement systems and their relation to basic display measurement tasks.

The reproducible quantification of anti-glare layer based display sparkle with Imaging Luminance Measurement Devices (ILMD) is essential for testing and conformity assessment of many displays aiming at outdoor applications. This study systematically researches relevant setup and system influences of a Fourier space-based sparkle evaluation. These include 13 different antiglare layers, two displays with different PPI, and several different system setups featuring 12 different camera/lens combinations and more than 10000 individual luminance images. Based on the resulting sensitivities, the measurement procedure is optimized with respect to the achieved reproducibility. The resulting procedure serves as basis to define a new automotive specification for reproducible sparkle measurements and may do so for other applications, that need to quantify sparkle in a reproducible way.

Imaging Luminance Measuring Devices (ILMDs) have become indispensable in the field of display characterization. The ability to capture the entire display with one measurement and to examine it for specific characteristics is only possible with such a spatially resolving system. With the completion of work on CIE TC2-59, ILMDs can now be characterized and compared. The following paper describes the basic terms surrounding the use of ILMDs. Furthermore, the characterization will be explained with some examples and the appropriate selection of the measuring instruments will be shown with examples of some tasks with respect the display ratings (i.e. average luminance and uniformity).