VisionCAL® is a patented, turnkey solution for LED screen manufacturers and installers that can be used to dramatically improve color and brightness uniformity in LED displays. The system is designed to be flexible enough to address LED module correction needs in a controlled factory environment and also to perform in-field correction of the large, spectacular LED video screens used in stadiums, in arenas, for outdoor advertising, or for large indoor displays.
The human eye is very sensitive to variations in color and brightness, especially on LED video displays, where adjacent points (individual LEDs) and areas (LED modules) can readily be compared. Differences in color as small as 2 nanometers in wavelength and 3% in brightness are easily noticeable. Because of the inherent variability in LED performance and the large number of LEDs used on large screens, clearly-noticeable variations are almost impossible to avoid, even with very careful and expensive LED binning. This difficulty is magnified because LED performance will vary as a function of temperature and humidity, and so differences can occur from day-to-day even on the same production line.
The most cost-effective and adaptable method of achieving color and brightness uniformity for LED screens takes advantage of the science of LEDs and LED screen pixels: LED brightness can be reliably regulated by adjusting the power supplied to an individual LED, and the perceived color of an LED pixel can be adjusted by color mixing.
The Radiant Vision Systems VisionCAL system uses a ProMetric® Imaging Colorimeter to measure the color and brightness of every LED in an LED module or screen.