Understanding changes in performance as a function of view angle is important for display technologies and for lighting sources. Because of the size of many of these devices, or because there is a need to observe view angle performance over a large spatial area, it is often impractical — due to physical testing space requirements — to move the imaging colorimeter around the device under test. In this case, a practical solution is to use a two-axis goniometer to move the device under test within the view of the imaging colorimeter, allowing sequential imaging from multiple viewing angles.

Radiant Imaging’s PM-FPMS and PM-NFMS systems are a cost effective, automated means for doing exactly this. A combination of dedicated control and analysis software, a PM Series™ Imaging Colorimeter, and a specialized goniometer, these systems are designed to automatically gather spatial light and color measurements from multiple viewing angles. Depending on the device under test — a display or a light source — application specific analysis software provides all the performance data required for device assessment and modeling. The FPMS/NFMS goniometer is available in multiple sizes to meet all common measurement requirements.

PM-FPMS provides full control for automated view angle performance measurement for displays

The PM-FPMS™ system performs brightness and color uniformity measurements as a function of viewing angle for flat panel displays. It is designed to provide accurate view angle performance measurement data for developers of LCD, PDP, OLED and LED displays, as well as of LED, CCFL and lamp-based backlights. Because the PM-FPMS system captures a full image of the display or component at each measurement angle, it provides much more comprehensive information than can be obtained from traditional spotmeter-based measurements.

PM-NFMS provides near-field models for large light sources, enabling illumination modeling

The PM-NFMS™ system performs brightness and color uniformity measurements as a function of viewing angle for large light sources, generating a near-field luminance distribution model. The near-field model — which is in Radiant Source™ Model format — can be used to analyze the performance of the light source directly, or it can be converted to a far-field distribution and used to extrapolate the illumination distribution of the source at any arbitrary distance. Because the PM-NFMS system is able to perform these measurements with the imaging colorimeter placed close to the light source, illumination distributions can be performed in a much smaller laboratory space than can be achieved by using a spotmeter to obtain a far-field distribution.