Abstract
This application note aims to educate users on the benefits of using Matrox Design Assistance to carry out visual quality inspections for OLED displays.
Problem Statement
OLED (Organic Light-Emitting Diode) displays and MicroLED are part of modern display technologies used in mobile phones, televisions, computers, and many more. Basically, an OLED display is based on an organic substance used as the semiconductor material in LEDs.
However, users might face a few challenges while carrying out visual quality inspections for these displays. This includes checking on the luminance for each subpixel, to ensure that each subpixel output is of the same brightness; Colour non-uniformity, where varying brightness levels for each subpixel may reduce the colour accuracy and colour non-uniformity across the display; And checking for defecting pixels, which includes dead pixels, hot pixels, or stuck pixels.
Moreover, users usually need to detect defective pixels, especially on LED panels, to categorise the final products into different grades. These defects are impossible to see with the naked eye.
Hence, how can users easily carry out these inspections?
Figure 1: Setup image of Basler 20MP acA5472-17uc colour camera, Myutron FTV60C-110 Telecentric lens 6X and a smartwatch.
Solution
For this application, we used Matrox Design Assistant software to carry out the visual quality inspection on a smartwatch display, along with a Basler 20MP acA5472-17uc colour camera and a Myutron FTV60C-110 Telecentric lens 6X to capture the image.
Figure 2: Matrox Design Assistant graphical web-based operator view
The Matrox Design Assistant can build an intuitive flowchart, and users are able to design a graphical web-based operator for applications. The software is also one of the Test Execution and Analysis Software used for these types of display panel inspections. It is part of a production-line software used for image analysis to identify defects and quality issues, and evaluate the measurements of the LED panels to categorise the final products into different grades.
This means that the software can match colour data to match RGB values on the smartwatch display panel and industrial standards. This is to ensure each subpixel output is of the same colour accuracy. At the same time, the software can convert the RGB data to HSL and CIELAB and perform the match in those colour spaces.
Figure 3: 6X magnification of OLED panel from the smartwatch
Figure 4: Singled out RGB colour data
The software is also able to check the intensity of each colour, to ensure that the grey values on each LED in the smartwatch screen panel are equal and of the same brightness. Lastly, Matrox Design Assistant is able to calculate the number of LEDs in each display panel.
