Let me clarify the zero dead pixel warranty.
I understand that people pay hard-earned money for an LCD monitor and they expect it to be perfect. In reality, no manufacturer today can promise a flaw-free LCD monitor. Like diamonds most LCD panels have some amount of defects. People don't think twice about paying more for a diamond with less flaws and better color.
Limitations of the LCD manufacturing process sometimes result in dead sub-pixels. Three sub-pixels one red, one green and one blue make up a "Pixel". A dead "pixel" three adjacent sub-pixels is rare, however dead sub-pixels are very common. A "dead sub-pixel" can take the form of either a black or colored spot on a white background or a white or colored dot on a black background. Since this is a manufacturing issue sub-pixels typically will not go bad over time.
The manufacturing process for LCD displays requires millions of transistors in each panel that make up the sub-pixels. For example a 1280 x 1024 panel has (1280 x 1024 x 3) = 3932160 sub pixels. LCD panels are made exactly like integrated circuits (IC's), basically a big silicon wafer. The difference is that there are hundreds of IC's on a single wafer. Those close to the edges of the wafer are more likely to fail and are simply thrown away. The remaining good IC's are packaged. The amount of dead IC's defines the yield of the wafer.
Now imagine a single 17.4 Inch LCD wafer. It is huge as compare to an IC wafer and is more difficult to manufacture and just as prone to manufacturing problems as an IC wafer. The difference is you get a single panel from one wafer. And the manufacturing cost is the same whether the panel is perfect or not. Let's assume the LCD yields are 70%. This means that 30% of every LCD panel has some amount of defects (dead sub-pixels). Imagine how expensive cars would be if auto makers had to send 30% of their new cars just off the assembly line to the junkyard to be crushed. Someone needs to pickup the cost of those cars. OK maybe this is an extreme example but it applies.
Now I have a question, would you be more comfortable purchasing from a manufacturer who is up front and will tell you in plain English what the dead pixel policy is?
The f1200 allows No dead "Pixels" however it does allow for up to 12 defective sub-pixels. Three adjacent sub-pixels are not allowed.
NEC/Mitsubishi recently put out this press release on dead pixels.
Press Release
It says "pixel faults are limited to a maximum of two dark and two light pixels as well as a maximum of five defective sub-pixels per million or .0005 percent failure rate of sub-pixels"
The way I read it this means that the spec allows two dark and two light pixels for a total of 12 sub-pixels. Or 5 dead sub-pixels per million, since there are 3.9 million sub-pixels on a 1280 x 1024 panel this allows for up to 19 dead sub-pixels.
I hope I'm reading this correctly. Please correct me if I'm wrong.
Jim Witkowski
Chief Hardware Engineer
Cornerstone / MonitorsDirect.com