Swiss company Escatec has developed a new method of testing LCD displays with a camera, while compensating for moiré. Moiré is the set of patterns visible on an LCD screen when viewed through a camera lens. They are caused by interference between the images in the LCD arrays and the image sensor in the camera.
Any slight angle of difference between the arrays leads to a moiré pattern. In this case, cameras cannot be used to verify that the output from the LCD display is correct and checking by an operator is required.
Escatec found that offsetting the camera and screen by 45° resulted in ‘very predictable’ moiré patterns, meaning that it was much easier to verify the display.
Automated testing is used to speed manufacturing and reduce human costs.
The same equipment can be used for LED testing and characterisation and the company claims that its technology reduces testing time by 90%.