16
12. Pixel defects on screens
5 Pixel
Rows
Sub-Pixel
Pixel
blue
green
red
5 P
ix
e
l
For active matrix TFTs with a resolution of 3,440 x 1,440
pixels, which are each made up of three sub-pixels (red,
green, blue), there are a total of approximately 14.9 mil-
lion control transistors in use. Due to this very high
number of transistors and the associated extremely
complex manufacturing processes used, occasionally
one or more pixels can fail or become incorrectly cont-
rolled.
The ISO standard ISO 9241-307 defines, amongst other
things, the generally applicable guidelines relating to
pixel defects. Pixel defects are categorised into four
fault classes and three defect types. Every individual pi-
xel consists of three sub-pixels, each of which is assig-
ned a basic colour (red, green, blue).
Pixel fault class
Defect type 1
Pixel constantly lit
Defect type 2
Pixel constantly
black
Defect type 3
Defective sub-pixel
lit
black
0
0
0
0
0
I
1
1
2
1
0
1
3
5
II
2
2
5
5-n*
0
0
2xn*
10
III
5
15
50
50-n*
0
0
2xn*
100
IV
50
150
500
500-n*
0
0
2xn*
1000
n* = 1.5
The table describes the maximum number of pixel failures allowed on the screen, before a warranty
claim arises. A warranty claim may be applicable if the above number of defects in a category is ex-
ceeded.
