Notes On The Pixel Fault Class - Caratec CAV192LDTS User Manual

10.1 Notes on the pixel fault class

Unless indicated to the contrary, all the flat screens supplied by Caratec GmbH comply with
Class 0.
In case of flat screens pixel defects occur related to technology and production. A 22" display
with a resolution of 1920 x 1080 pixels e.g. consists of more than 2 million individual screen
cells controlled by tiny transistors. With such a tremendous number it is possible that in
spite of highest quality standards one or several individual cells are not perfectly functioning,
and are permanently switched on or off. Then, the outcome are continuously shining or
continuously black pixels on the screen.
In this respect, the ISO standard 9241-307 defines quality classes providing transparency
with respect to warranty claims of final customers, retailers and wholesalers against the
manufacturers. With the commitment to an ISO defect class, the monitor manufacturers
undertake to comply with the corresponding standard for serial production. In this, the pixel
defect classes are guided by the number of pixel defects and by the specific defect type, as
explained in the following table.
Defect class Fault type 1
Defective pixel
Always on
0 0
I 1
II 2
III 5
IV 50
The pixel defect number is defined each time per 1 million pixels.
Explanation:
A continuously shining pixel (defect type 1) is more disturbing for thee user than a continuously
black pixel (defect class 2). The least evident is, if only one subpixel is defective, and shines
in one of the three colours red, green or blue, or is black (defect class 3).
Because of these differences also the respective accepted number of defects of the three
defect types is different, e.g. in class II.
48
Fault type 2 Fault type 3
Defective pixel Defective sub-pixel
Always black Always on
0 0
1 2
2 5
15
150
Fault type 3
Defective sub-pixel
Always black
0
2
2
Up to 50
Up to 500