Challenges with Goniometric Characterization of Curved Displays

The transition from traditional flat displays to continuous curved displays in automotive applications has introduced new challenges for optical display measurement. The curvature and size of such displays complicate the alignment between the goniometer’s fixed coordinate system and the display’s coordinate system, which is required for complete angular scans. Maintaining a constant working distance between the LMD and the display surface further necessitates motion that follows the display’s geometry. These requirements become even more demanding under temperature-controlled measurement conditions.
A combination of algorithm for coordinate transformation, 7-axis goniometer and a new concept of temperature chamber design enables compliance with the geometric and thermal constraints required for accurate characterization. Results of various measurement procedures, including SWC, EOC, and ISO-Scan, are presented with respect to their implications for display metrology on curved surfaces.