Regarding the observed panel symptom, it is commonly known as image sticking, which is also referred to as image retention or image persistence in the display industry.
Image sticking occurs when parts of an image temporarily "stick" on the screen after that image is gone and will remain unchanged and visible on the screen in the same location for a long period of time. Unlike CRT monitors, LCD monitor image sticking is not permanent, but constant images being displayed for a long period of time should be avoided. As image sticking presents in all types of panel technology and is more prominent in IPS panels, here are some tips that users can try to avoid or get rid of symptom when image sticking occurs.
How to avoid image sticking:
1. Please always turn off your display when it is not in use, as this helps extend screen life and minimizes the occurrence of symptoms.
2. Set up 3-minute screensaver that contains bright visuals for your display in the OS of your laptop.
How to get rid of image sticking:
1. Enable the Burn-in Cleaner function in the system menu (for PD2705Q, PD3420Q, and PD2725U only).
2. Play a colorful and fast-moving video with a lot of color changes (for a few minutes to half an hour) until the symptoms begin to disappear. Example video can be found on YouTube (Search: HD LCD Screen Burn In Fix)