20X Microscope Lens

Displays continue to increase in resolution and pixel density. Microdisplays such as those used for AR/VR/MR devices and smart watches can have hundreds or even thousands of pixels per inch (PPI). At the same time, these pixels and their subpixels can be as small as a few microns across. Manufacturers need to measure much smaller elements than ever before to ensure accuracy of light output, color, and other qualities.

This is especially true of emissive displays like OLED, LED, microLED or microOLED where each pixel in a display produces its own luminance and therefore can vary in output from pixel to pixel. These individual variations (called mura) can cause non-uniformity of the display that is visible even at a distance, especially when viewing the display at high bright states. 

The 20X Microscope lens can be used with a ProMetric Y-series Imaging Photometer for luminance-only measurement or a ProMetric I-series Imaging Colorimeter for measuring values of luminance and chromaticity. Extensive data analysis and display functions are also supported, including isometric plots, cross-sectional graphs, radar plots, and bitmaps.

Evaluate Individual Display Pixels

The magnification of the 20X Microscope Lens enables the imaging colorimeter or photometer to focus a greater number of image sensor pixels per display pixel for fine-detail measurement. Paired with a ProMetric® Imaging Photometer or Colorimeter, it enables users to acquire more precise pixel detail and increase the consistency of accurate measurements. The lens magnifies details of the display sensor while capturing display pixels and subpixels over several sensor pixels of high-resolution (61MP) image sensors for increased measurement precision. This combination of value, high performance, and flexibility offers manufactures easy-to-use measurement control, optimizing testing efficiency and supporting advanced analysis.

Emissive display subpixel luminance shown in false color scale.

Once measured, discrepancies in output from pixel to pixel can be calculated and applied as corrections. This normalization of pixel outputs (called demura) produces a display of entirely uniform appearance. These calibrations can be carried over from design to ensure accurate pixel output for the given substrate or pixel layout of devices in production operations.

Characterize Subpixel Patterns

Subpixel patterns can be challenging to characterize without a very high-resolution system and optics capable of microscopic measurement. The 20X Microscope Lens magnifies images by a factor of 20, enabling design manufacturers to ensure accurate subpixel layouts, shapes, and RGB color patterns. As shown in this image, the 20X Microscope Lens can achieve extreme detail in a very small spatial area to properly image individual elements with a substantial amount of separation between light regions.

Full FOV image of an emissive display captured using a ProMetric 61MP Imaging Colorimeter with 20X Microscope Lens. Inset: Zoomed in image of a single subpixel.