Interest in emissive displays like OLED, microLED (µLED) and miniLED continues to grow. As displays with small, independent light-emitting elements become more common, quality inspection—to ensure display quality and uniformity—requires more advanced visual inspection technologies. Traditional LCD displays using LED backlights produce only a moderate amount of variability across regions of the display screen. With OLED/µLED displays, however, every individual emitter can be subject to a high a degree of variability in luminance and color.
Samsung’s 75” microLED television, on display at CES 2019.
Visual quality inspection must be able to measure at the pixel and sub-pixel level to detect these differences. It might seem like the obvious conclusion that using imaging systems with higher resolution sensors (e.g., 80MP or more) for display measurement are the answer. But high resolution alone doesn’t influence measurement performance. Other factors such as sensor type (mainly CCD and CMOS), pixel size & fill factor, full well capacity, and dynamic range are key—and controlling thermal noise, read-out noise, and signal-to-noise ratio ultimately determine the quality of images captured my measurement systems and thus the accuracy of any visual inspection regimen.
The Radiant ProMetric® 43MP Solution
Radiant has thoughtfully designed high resolution into our latest system—the ProMetric® Y43 Imaging Photometer—working closely with our sensor supplier to improve resolution without sacrificing image quality and measurement capability. The ProMetric Y43 features a 43-megapixel scientific-grade, cooled CCD sensor that limits image noise for highly accurate, repeatable imaging. It has high spatial resolution, allowing the camera to detect pixel and sub-pixel luminance and color variations across an entire display, for all bright states (gray levels),as well as catch subtle surface anomalies or particles, and other defects that are easily missed by human visual inspection or competitive measurement systems.
The Radiant ProMetric® Y43 Imaging Photometer.
Defects in images can be identified and quantified using Radiant’s TrueTest™ Automated Visual Inspection Software (available with tests for comprehensive display defect detection, mura identification & assessment, or application-specific testing of automotive displays, head-up displays, and augmented or virtual reality displays). TrueTest applies objective analysis and repeatable pass/fail criteria to Y-series images for fully automated quality control. With quality, highly detailed images provided by the Y43 imaging system, TrueTest’s ability to qualify displays becomes even more precise.
See it in Action at SID Display Week
The ProMetric Y43 will be among many of the products showcased at Radiant’s booth (#1220) at Display Week 2019. At the show, Radiant will feature demos of the latest measurement solutions for ensuring the quality of displays, illuminated components, and device surfaces. Live demonstrations showcase high-resolution photometric imaging systems, software, and specialized lenses for evaluating the unique characteristics of light and color in displays used in smart devices, automotive integrations, augmented and virtual reality (AR/VR), and other emerging applications.
The Display Week exhibition takes place May 14-16 at the San Jose McEnery Convention Center in San Jose, California, U.S.A. Organized by the Society for Information Display (SID), Display Week is the world’s leading event for electronic display innovation. The Radiant booth will feature 12 product demonstrations, each addressing an emerging technology or efficient measurement method in the display market:
Production-Level Testing– At the forefront of its booth, Radiant will underscore the form factor, efficiency, and automation benefits of its single-camera/software solutions in demonstrations of production-level testing for quality control—including uniformity analysis of three different types of displays on a line (LCD, OLED, and E Ink), regional testing and gamma correction of local-dimming displays (LED backlit LCD), and a proprietary method used to register pixels at high resolution to detect non-uniformity in OLED displays.
A foldable display based on OLED technology—expect to see more of these at Display Week 2019!
Emerging Technologies – Released this January, Radiant’s new Near-Infrared (NIR) Intensity Lens (recipient of a Vision Systems Design 2019 Innovators Award), expedites the process of measuring near-infrared light sources used for facial and gesture recognition, eye tracking, LiDAR, and other 3D sensing technology.
AR/VR – Radiant will showcase innovative optical solutions for near-eye display (NED) performance (using a photometric imaging system paired with a wide-angle lens). Our AR/VR Lens is used for testing VR headsets, and evaluation of augmented projections through AR smart glasses. With aperture at the front of the lens, the Radiant AR/VR Lens is able to capture the full angular FOV of NEDs through headsets and goggles from the human eye position.
Radiant’s AR/VR Lens will be demonstrated measuring luminance (brightness) and uniformity of the augmented reality display of the Vuzix Blade® smart glasses.
Automotive Displays – Radiant will debut new capabilities of its TrueTest™ Software at Display Week, which address specific measurement needs in the automotive industry. New TrueTest modules feature series of tests for head-up display (HUD) optical performance testing (the new TT-HUD™ module) and algorithms for easy analysis of free-form display area (an enhanced “Register Inside Display Area”—or RIDA—feature for evaluating non-rectangular displays in the new TT-AutomotiveDisplay™ module).
Radiant tests automotive head-up displays (HUD), including the latest AR-style projections, which display images at variable sizes and distances on an infinite plane.
Adjacent to these demos, visitors can rate the visual effect of “sparkle” on automotive anti-glare displays and compare their perception of display quality to measurements taken by a Radiant imaging photometer.
Surface Inspection – Beyond light and color measurement, Radiant will demonstrate how the application of photometry-based systems can be extended to inspect non-lit assemblies and surfaces for total device quality. Radiant’s advanced vision technology leverages the company’s high-resolution and low-noise CCD imagers—engineered to detect subtle variations of light—and applies these advantages to precision defect inspection of randomly-occurring anomalies such as scratches and debris on cover glass and surfaces.
Stop by Booth #1220 and scan your phone with our surface inspection system to instantly detects scratches, particles, and other cosmetic defects.
Visitors are invited to try the Radiant surface inspection solution at the booth, testing their own smartphone device to see what kind of surface defects the photometry-based system can detect on the fly—even those invisible to the eye.
Join us at SID
If you’ll be in San Jose at Display Week this week, stop by Radiant Booth #1220 to get a firsthand look at how we apply these solutions and others to address measurement challenges for all aspects of a display device, using objective data to quantify human visual perception of quality.
Get a Complimentary Exhibit Hall Pass Using the Radiant Discount Code: