Why does the camera always flash when shooting the computer screen?

The screen displays pictures at a certain refresh rate. Light and dark stripes will appear during the refresh process, but the refresh time of dark stripes is very short, which exceeds the perception range of the eyes, so the eyes can't see the stripes. In order to achieve a better photo effect, the mobile phone camera uses a higher scanning frequency, so it can shoot stripes or twill, which is a natural physical phenomenon and does not belong to the camera or screen display failure. It is suggested that you appropriately increase the screen brightness of the subject before shooting, and the effect will be improved.