Testing LCD panels and liquid crystal test cells is one of the most common applications for Axometrics measurement systems. We revolutionized the industry when we introduced full-Mueller-matrix testing to this market in 2005.

Using our patented Mueller Matrix Method, Axometrics systems can measure all parameters a liquid crystal cell simultaneously:

• Cell gap
• Rubbing direction / Alignment direction on both the TFT and CF glass
• Twist angle
• Pre-tilt angle on both the TFT and CF glass

The measurement works on every mode of liquid crystal, including twisted, parallel rubbed, anti-parallel rubbed, vertically aligned, and hybrid cells. Our software includes an automatic detection function so you can successfully make measurements even if you do not already know what type of LC geometry you are testing.

Using AxoScan, the measurement is fast enough that you can scan a nearly unlimited number of XY points on a panel.

High-resolution XY scan of cell gap made by AxoScan

For making measurements inside of one pixel, the AxoStep imaging polarimeter is an ideal choice. This is important for Multi-domain designs, Investigating LC behavior near patterned electrodes, and analyzing bad or damaged pixels. 

Cell gap and alignment direction variation within the subdomains of one pixel in a PSVA panel as measured by AxoStep.

Additionally, we offer solutions for measuring liquid crystal devices versus applied voltage, and temperature chambers for measuring gravity-induced cell gap defects (mura) when panels are heated and held vertically.

Another key measurement made for LCD panels is the off-axis retardation (Rth) of the color filter layers. It is known that large off-axis retardation of color filters can decrease the contrast ratio of a panel. The AxoScan’s ability to measure low retardation values proves useful in this application.

Off-axis retardation of a patterned color filter measured by AxoScan

Axometrics has worked closely with most of the world's leading LCD manufacturers to develop measurement solutions throughout the R&D, manufacturing, and QC stages of production. Contact us today to learn more.