Problem

There are blinking diagonal lines or stripes on the photo or preview screen of the phone when the user uses it to take a photo or record a video for the computer screen.

Cause

In some computer products, the brightness of the screen is adjusted by using the PWM to control the light-emitting time of pixels. The images are refreshed at a defined rate, which is extremely quick and imperceptible to the human eye.

• When the brightness is 40%, the PWM screen-on ratio is 40%, which is equivalent to refreshing the screen with several groups of 40% bright bars and 60% dark bars. The scan frequency of the camera is relatively high, and can identify the bright and dark bars. Therefore, blinking diagonal lines or stripes can be seen during shooting.

  

• When the screen is at full brightness, the PWM screen-on ratio is 100%, meaning that the screen is refreshed with 100% bright bars each time. In this case, no stripes appear on the photo or preview screen.
• When the screen is set to the minimum brightness, the PWM screen-on ratio is 0%, meaning that the screen is refreshed with 100% dark bars each time. In this case, the screen is black.

Solution

This is normal and does not indicate a quality issue with your computer. Your computer has undergone rigorous reliability tests and material inspections.

Suggestions:

• Before you take a photo or record a video for the computer screen, adjust the screen brightness to 100%.
• It is recommended that you use the screenshot function of your computer to obtain the screen content.