LCD Screen "Shadow Bugs"

HoneycombWX · 13 May 2017

Not sure if this is a frequent problem with new LCDs, but in the case of mine, my LCD panel was secondhand and used. Unfortunately, there appears to be a shadow of what appears to be an ant or a small bug that appears between the LCD panel and the backlight. While I did manage to move it around some by sticking a suction cup to the part of the screen where this "shadow bug" is at, I only managed to get it only partially away from the top border of the screen.

So, what causes these "shadow bugs" to appear on the LCD to begin with? I thought it was just a speck of dirt but then it wouldn't come off.

LCD Screen "Shadow Bugs"-cfas8miviaqcrd0.jpg

Fafhrd · 13 May 2017

An instance of pressure on the screen may cause the spacers and seals between each colour cell (3 for each pixel made up of Red, Blue, and Green) to deform allowing the Liquid crystal medium to spread across several cells, so that the cells cannot be energised to pass light of any colour and appearing as a black shadow. Sometimes a single colour cell is energised by neighbouring cells, resulting in a permanent red, blue or green pixel.

Using suction cups or pressure or tapping the screen can create these artefacts, as well as sometimes remove them.

Alternatively, the diffusion layers of the screen behind the LCD glass can have particles of dust introduced when the screen is jarred, or very small insects may crawl and be trapped to die there, resulting in small shadows.