How to deal with the afterimage on the display screen of small and medium-sized LCD screens

    When debugging the code of small and medium-sized LCD screens, software engineers occasionally encounter afterimages on the LCD screen, or they may encounter it after using the display screen for a period of time. First of all, everyone needs to understand what afterimage is. Afterimage on the display screen means that the content or picture displayed previously still exists when we switch to the next screen, but the color or font of the picture is lighter than the normal picture. The appearance of afterimage (afterimage) is usually related to the response characteristics of liquid crystal molecules, usage habits or hardware status. You can check and deal with it according to the following steps:

A. Determine the type of afterimage

First, distinguish whether it is temporary afterimage (recoverable) or permanent afterimage (irreversible):

· Temporary afterimage: It is mostly caused by the liquid crystal molecules maintaining the same state for a long time (such as static pictures), resulting in "fatigue", which usually disappears gradually through rest or adjustment.

· Permanent afterimage: It is mostly caused by aging of the LCD panel, physical damage or hardware failure, which is difficult to recover by itself and requires replacement of the LCD screen.

B. How to deal with temporary afterimages

If the afterimage is new and the degree is relatively mild, you can try the following operations:

1. Force activation of liquid crystal molecule movement

Liquid crystal molecules need to be "active" to restore their responsiveness, which can be done in the following ways:

· Play dynamic content: loop high frame rate videos (such as 60fps or above), scrolling text or dynamic wallpapers for 10-30 minutes to help the liquid crystal molecules restore their elasticity.

· Full white/full black screen refresh: cover the screen with pure color pictures (full white, full black, red/green/blue monochrome), and display each color for 5-10 minutes.

· If conditions permit, you can bake the LCD screen in an oven, setting the temperature to about 60 or 70 degrees to speed up the flow of liquid crystal molecules and reduce the afterimage of the screen.

2. Adjust display settings

· Reduce brightness and contrast: high brightness will accelerate the aging of liquid crystal, and dimming the screen can reduce molecular pressure (setting path: Settings → Display → Brightness/Contrast).

· Turn off display enhancement: Some mobile phones' "dynamic contrast", "local dimming", "HDR" and other functions may aggravate the afterimage, so temporarily turn off the test.

· Adjust the refresh rate (if supported): High refresh rate (such as 90Hz/120Hz) can reduce screen drag. Try switching to a higher refresh rate mode (Settings → Display → Refresh rate).

3. Avoid continuous display of static images

In daily use, try to avoid displaying fixed images for a long time (such as navigation, e-books, game menus). You can turn on automatic screen off (Settings → Display → Sleep time adjusted to 1-2 minutes), or use a screen saver (dynamic rather than static images).

C. Troubleshooting software/driver issues

If the afterimage is accompanied by display abnormalities (such as screen distortion, flickering), it may be related to the driver or system:

1. Re-debug the matching software code and update the initialization code of the display.

2. Adjust the refresh rate of the display.

If the afterimage is caused by abnormal system files, try to back up the data and restore to factory settings (Settings → System and Updates → Reset → Restore Factory Settings).

D. Hardware problem handling

If the above methods are ineffective, the afterimage may be caused by hardware failure and further testing is required:

1. Check the cable/interface (for detachable devices)

The screen of some devices is connected to the motherboard via a cable. Loose or oxidized cables may cause abnormal signal transmission. You can use a dust-free cloth with anhydrous ethanol to wipe the gold fingers of the display cable to remove the dirt and oxide layer on the gold fingers.

2. Panel aging or damage

· Aging: The life of an LCD panel is usually 50,000-80,000 hours (about 17 years based on 8 hours of use per day). Long-term high-brightness use will accelerate aging and cause irreversible afterimages. In this case, the LCD screen can only be replaced.

· Physical damage: Squeezing, impact or high temperature may cause leakage of the liquid crystal layer and dislocation of the crystal, forming permanent afterimages.

     When encountering afterimage, we need to rule out whether it is a hardware problem or a software problem, so that we can find a solution. Shenzhen Hongjia Technology specializes in R&D, production and sales of 1.14-inch to 15-inch LCD screens and matching touch screens. It has 12 years of industry experience and a group of experienced engineers. It can provide customers with one-stop solutions and can also be customized. You are welcome to email us for consultation.