Subpixel Disease on LCD Displays
"Subpixel Disease" is a term I coined to describe a problem that affects (so far) certain Active Matrix LCDs manufactured by IBM and Hitachi.
What is subpixel disease?
Affected displays will look perfect for the first few seconds they're powered on, but then subpixels around the edges of the screen will begin to get stuck on. This can vary in severity from hardly noticable, to rather severe. Subpixel disease is distinct from others types of pixel degredation (regular bad pixels or "pixel rot/screen cancer") as the affected subpixels work fine when the display is first powered on.
Subpixel disease is also distinct and unrelated to Tunnel Vision. While tunnel vision creates a natural "vignette" effect, subpixel disease is far more random. It also only takes around 20-30 seconds for all the malfunctioning subpixels to present themselves, while displays with tunnel vision can vary from taking seconds to hours to fully degrade.
What displays are affected?
So far, I have only seen subpixel disease occur on displays made by Hitachi and IBM. I believe Hitachi had something to do with IBM's display division, so that would explain why they're the two brands affected. Only Active Matrix displays are affected by subpixel disease. The majority of affected panels seem to be ones from the mid 1990s, like the 12.1-inch 800x600 displays used in the ThinkPad 760 Series and the ThinkPad 560. The Dell Latitude LM is another commonly affected laptop. It can also affect the Hitachi TX24D55VC1CAA, an 9.5-inch 640x480 LCD from circa 1994.
What causes subpixel disease?
Unfortunately, I do not know. It is likely just a natural degredation of these LCDs. I have hypothesised that excessive pressure being placed on the LCD may play a role, but I do not know if this is true.
Can it be repaired?
So far, there are no known ways of repairing an LCD with subpixel disease.
How common is it?
Subpixel disease is very common, but it is not very difficult to find unaffected panels as of 2025.
Gallery
Dell Latitude LM with subpixel disease. The first photo shows the LCD within the first couple seconds of power-on, before subpixel disease has set in. The second photo shows the laptop booted to the desktop, after subpixel disease has set in. The third and fourth photos show close-ups of the malfunctioning pixels.
WinBook XP with the 640x480 Hitachi LCD, affected by subpixel disease. The lower resolution allows you to see the behavior more clearly than the 800x600 panel of the Latitude.
Page last updated (MM/DD/YYYY): 09/29/2025
Update Reason: page created
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