Method for testing the electromagnetic compatibility (EMC) of image screen devices, involves determining the deviation of the average value of a test signal for each discrete segment of test window

摘要

A method of testing the EMC of display screen devices which receive a test image signal from a test generator involves dividing the image information of a test window (15) into several parallel segments (18) and then determining a reference magnitude from a noise-free test image (13) in the test window (15). An average value of the signal is then formed and the deviation of the average value of each discrete segment (18) from the reference magnitude is calculated, followed by the variance of the deviations of all segments (18) of the test window (15). The calculation of the variance is then repeated for several test windows (15) each rotated by an angle increment and comparison between the variances of the deviations for the individual angles of rotation of the test window is made. A Independent claim is included for a test device for verifying the EMC of display screen devices.