Imagine if you will the start of a wrestling match, with two warriors on either side of the ring. The announcer takes the microphone center stage and bellows an introduction: “In this corner, the display industry — focused on the production of screens with ever-increasing resolution!” He pauses to allow the crowd, particularly the section filled with young gamers, to cheer its approval. “In this corner,” he continues, “the test and measurement engineers, ready to take on any challenge!” There is scant applause, perhaps, or maybe a couple of science geeks shouting encouragement.
The 20X microscope lens is designed to test displays comprised of individual LEDs, microLEDs and microOLEDs. Source: Radiant Vision Systems The crowd has a clear favorite, and it’s understandable: The display industry has been pulling out all the stops for years. There has been an evolution from liquid crystal displays (LCDs) using backlights to illuminate pixels to organic light-emitting diode (OLED) displays where each individual pixel illuminates itself, providing deeper blacks and higher contrast. The industry has shrunk OLEDs to microscopic sizes to yield greater response times in smaller spaces, a boon for augmented reality (AR) and virtual reality (VR) headsets. And to address OLED drawbacks such as screen burn-in and short lifespans, the industry has more recently turned its attention to shrinking the size of inorganic LEDs, resulting in microLEDs poised to be the cutting edge for display technologies.
Things aren’t quite as sexy on the other side of the ring, where the primary task is not to dazzle but to keep pace with this evolution. Yet while it might not be as obvious to the cheering masses, we’d all still be staring at monochrome computer screens and black-and-white televisions if not for the painstaking work of the test and measurement crowd. Among its latest accomplishments is a new 20X Microscope Lens from Radiant Vision Systems, designed to test small components and features such as individual LEDs, microLEDs and microOLEDs, along with display pixels and sub-pixels.
“Measuring the quality of emissive displays at the pixel and sub-pixel level has become a tougher challenge due to the size and number of pixels within one small display,” explained Radiant’s optics development manager Eric Eisenberg. “This solution provides manufacturers with definitive correction factors to adjust each display and evaluate all visual qualities as viewed from the AR/VR user’s perspective.”
The new lens mounts directly to a Radiant ProMetric imaging colorimeter or photometer, where its magnification enables either device to focus a greater number of image sensor pixels per display pixel for fine-detail measurement. Once measured, discrepancies in output from pixel to pixel can be calculated and applied as corrections to produce a display of entirely uniform appearance.
Calibrations can also be carried over from design to ensure accurate pixel output for the given substrate or accurate pixel layout for devices in production.
Thinking back to our imaginary wrestling ring, one might imagine the bell signaling the close of this latest round. And thanks to the new lens from Radian, it would appear that the crowd favorite has finally met its match.
