TFT Dead Pixel Allowances
LCD Displays are made up of a fixed number of pixels. Each pixel is made from 3 sub-pixels: one red, one blue and one green. Each sub pixel has its own transistor, so the manufacturing process to produce a TFT panel is highly complex. Due to this process, defects can occur at any time during the life of the panel. These defects cannot be fixed or replaced.
The standard of production techniques today cannot guarantee an absolutely fault free screen display. A few isolated constant lit or unlit pixels may be present.
To regulate the acceptability of defects and to protect the end user, ISO have created a standard for manufacturers to follow. ISO-13406-2 recommends how many pixel faults are acceptable before a panel can be replaced.
All LCD / TFT Monitors sold by Arbico Computers adhere to the ISO 13406-2 Spec in Class II with regard to pixel faults. ISO 13406-2 recommends how many defaults are acceptable in a display before it should be replaced, within the terms & conditions of warranty. Class II is the common class for consumer equipment. Class I is for Military, Hospital or other Critical applications. The below is relevant to Class II LCD panels.
The table below shows the allowable number of malfunctioning pixels that are acceptable, depending on the native resolution of the LCD and allowing for 2 malfunctioning pixels per million pixels.
| Native Resolution | No. of Pixels | No. of Million Pixels | Acceptable Defects |
| 1024 x 768 |
786,432 |
0.8 |
2 |
| 1280 x 1024 |
1,310,720 |
1.3 |
3 |
| 1600 x 1200 |
1,920,200 |
1.9 |
4 |
| 2048 x 1536 |
3,145,728 |
3.1 |
6 |
The table below shows the allowable number of malfunctioning sub-pixels that are acceptable, depending on the native resolution of the LCD and allowing for 5 malfunctioning sub-pixels per million pixels.
| Native Resolution | No. of Pixels | No. of Million Pixels | Acceptable Defects |
| 1024 x 768 |
786,432 |
0.8 |
4 |
| 1280 x 1024 |
1,310,720 |
1.3 |
7 |
| 1600 x 1200 |
1,920,200 |
1.9 |
10 |
| 2048 x 1536 |
3,145,728 |
3.1 |
16 |
The table below shows the allowable number of malfunctioning sub-pixels that are acceptable within a 5 x 5 block of pixels, depending on the native resolution and allowing for 2 malfunctioning sub-pixels within a 5 x 5 block, per million pixels.
| Native Resolution | No. of Pixels | No. of Million Pixels | Acceptable Defects |
| 1024 x 768 |
786,432 |
0.8 |
2 |
| 1280 x 1024 |
1,310,720 |
1.3 |
3 |
| 1600 x 1200 |
1,920,200 |
1.9 |
4 |
| 2048 x 1536 |
3,145,728 |
3.1 |
6 |
|
